Travelling often means jumping from open streets into steel-and-glass terminals and deep underground platforms. It’s no surprise your bars can vanish at the worst moments: boarding passes won’t load, ride-hail pickups fail, and messages loop endlessly. Airport and metro environments are brutal for radio signals, with thick materials, interference, and rapid movement that stress even the best networks. The good news: with a little prep and the right settings, you can keep your phone usable through most weak-signal zones. In this guide, we explain exactly why coverage collapses in airports and tunnels, how modern networks try to fix it (from distributed antenna systems to femtocells and “leaky feeder” cables), and what you can do—step by step—to stay connected. We also cover Wi‑Fi calling as a fallback and what happens if you need to place an emergency call when your device shows no service. If you’re planning trips, we’ll show how the right eSIM choice helps too.

Why airports and subways kill your signal

The physics problem

• Materials: Reinforced concrete, metal cladding, and low‑emissivity glass reflect and absorb mobile signals, especially higher‑frequency 4G/5G bands.
• Distance and line of sight: You’re often far from macro towers, buried below street level, or behind multiple walls.
• Crowds: Thousands of devices in a terminal create contention and interference; uplink (your phone to the network) becomes the bottleneck.

The mobility problem

• Handoffs: Moving quickly—airport rail links, shuttles, escalators—forces frequent “handoffs” between cells. If the handoff fails or the next cell is congested, calls drop and data stalls.
• Bands and tech mix: Networks may drop you from 5G to 4G to 3G/2G for coverage. Each step down can disrupt active sessions.

The infrastructure gap

• Not every venue invests in indoor solutions. Where they do, systems vary:
• DAS (Distributed Antenna System): A network of indoor antennas rebroadcasting outdoor cell coverage inside terminals and concourses.
• Small cells/femtocells: Mini base stations installed for targeted capacity—lounges, gates, or staff areas.
• In tunnels: “Leaky feeder” coaxial cables or dedicated radiating antennas carry mobile signals along the track.
• Multi-operator support varies. One operator may have great signal; another may have none.

How networks try to keep you connected

• Low-band spectrum: 700–800 MHz bands penetrate buildings better; you’ll often see more bars on these, though speeds may be lower.
• Carrier aggregation and DSS: Combine bands or share 4G/5G to keep sessions alive as you move between cells.
• VoLTE and VoWiFi: Modern calling stays on 4G/5G or falls back to Wi‑Fi calling, reducing circuit-switched handoff issues.
• Priority paths: Airports sometimes prioritise back-of-house and critical services. Public areas may share limited capacity.
• Emergency handling: Networks attempt to place emergency calls on any available cell, sometimes even on a rival network, depending on local regulations.

Before you go: a 10‑minute prep checklist

1. Install a local or regional eSIM - A multi-network or strong local profile can massively improve indoor performance. - Regional options like Esim Western Europe or Esim North America let your phone choose among partner networks. - Check country specifics on Destinations or install a country plan such as Esim United States, Esim France, Esim Italy, or Esim Spain.
2. Enable Wi‑Fi calling - iOS: Settings > Mobile Data > Wi‑Fi Calling. - Android (varies): Settings > Network & Internet > Mobile network > Wi‑Fi calling. - Confirm your phone shows “Wi‑Fi” or an icon in the dialler when active.
3. Download essentials for offline access - Boarding passes, rail tickets, hotel directions, offline maps, and translation packs. - Authentication apps: sync or note backup codes to avoid SMS dependency.
4. Adjust network settings - Prefer 4G/5G Auto; avoid “5G Only”. - Turn on Data Saver/Low Data Mode to handle captive Wi‑Fi and weak uplinks.
5. Power plan - Weak signal drains batteries fast. Start with 70%+ and carry a power bank.

Pro tip: Add airline and airport apps to “unrestricted battery” so they can load passes on flaky connections.

At the airport: practical tactics that work

Use venue connectivity wisely

• Join official airport Wi‑Fi and complete the captive portal; Wi‑Fi calling may not activate until the portal is cleared.
• If Wi‑Fi calling still won’t engage:
• Toggle Airplane Mode on, then enable Wi‑Fi only to force calling over Wi‑Fi.
• Disable VPN temporarily; some VPNs block Wi‑Fi calling’s IMS traffic.
• Forget and rejoin Wi‑Fi if the portal pops up again.

Choose your spot

• Near windows or open atriums generally improves signal.
• Avoid dense metal structures (security lanes) and sublevels when placing important calls.
• Lounges may have small cells; a quick signal check can be worthwhile.

Manage handoffs

• If a call keeps dropping as you move, step aside and finish the call stationary.
• For video calls, switch to audio or pause video while walking between concourses.

If data stalls but bars look fine

• Try switching to 4G/LTE from 5G; some indoor DAS nodes still deliver steadier 4G.
• Toggle Mobile Data off/on, or briefly toggle Airplane Mode to trigger reselection.
• Manually select a different network if your eSIM allows it.

Pro tip: Some gates have better indoor coverage because they sit under newer DAS clusters. If you find one that loads fast, stay put while you upload photos or sync documents.

Underground and on the metro: what’s different

• Not all lines have mobile coverage. Some systems cover platforms only, others include tunnels, and some rely purely on station Wi‑Fi.
• Coverage can switch every few hundred metres as the train passes tunnel antennas, causing brief dropouts.
• Speed matters: fast lines can outrun small-cell footprints, making uplink patchy.

Staying connected below ground

• Make Wi‑Fi your default:
• Set your phone to auto-join official metro Wi‑Fi; finish any captive portal step at the first station.
• Keep Wi‑Fi calling enabled. You can often place calls and send messages between stops.
• Prepare for tunnel blackouts:
• Queue messages and downloads.
• Use offline navigation between stations and refresh when the train stops.
• For critical tasks:
• Wait for a station with platform coverage.
• If you must call, stand near the platform centre where antennas are typically positioned.

Pro tip: If the metro has partial coverage, switch chat apps to “low bandwidth” or audio-only modes to ride out tunnel gaps.

What if you need to call emergency services?

• Your phone will attempt to place emergency calls (e.g., 112, 911, 999) on any available network, even if your own provider has no service. This behaviour depends on local regulations and device support but is widely implemented.
• If you see “No Service”:
• Try the emergency number anyway; the phone will scan for any cell that can carry the call.
• Move towards open areas, station entrances, or near windows to improve odds.
• Wi‑Fi calling and emergencies:
• In many countries, emergency calls are supported over Wi‑Fi calling, but not everywhere. If Wi‑Fi is the only option, complete the captive portal and try—your phone will choose the best available path.
• If Wi‑Fi calling is unavailable for emergency calls, the device will attempt cellular instead.
• Location sharing:
• Modern systems can transmit your location (Advanced Mobile Location/AML) when you call emergency numbers. This may not work over all Wi‑Fi networks.

Note: Rules and capabilities vary by country and operator. If in doubt, move to an area with clear cellular coverage as soon as it’s safe.

Troubleshooting quick wins

Try these in order when signal or data misbehaves:

1. Toggle Airplane Mode on for 10 seconds, then off.
2. Turn Wi‑Fi off and on; complete any captive portals.
3. Switch network mode to 4G/LTE and back to 5G Auto later.
4. Manually select a different partner network (if your eSIM allows).
5. Reset network settings only if the above fails (you’ll need to rejoin Wi‑Fi networks).

Pro tip: Save your eSIM QR and plan details offline before you travel in case you need to reinstall after a network reset.

Picking the right eSIM for hard-to-reach places

• Prefer plans with multi-network access in your destination so your phone can latch onto the operator with the best indoor/DAS presence.
• If you’re visiting multiple countries or transiting through major hubs, regional eSIMs simplify coverage:
• Esim Western Europe for intra‑EU travel where metro coverage varies city by city.
• Esim North America for the US and Canada, where low-band 5G/4G differs by carrier and airport DAS deployments are uneven.
• Country-specific options can outperform roaming in airports with single-operator DAS:
• Esim United States
• Esim France
• Esim Italy
• Esim Spain
• Check operator notes and airport/metro coverage on Destinations.

For teams on the move, pooled data and policy controls help ensure staff stay reachable in terminals and tunnels. See For Business for options. Venue and travel partners exploring indoor solutions can visit our Partner Hub.

Tech corner: femtocells, DAS, and “leaky feeders” explained

• Femtocells and small cells: Low‑power base stations that improve coverage in a small area like a lounge or gate cluster. They attach to backhaul (often fibre) and broadcast licensed spectrum.
• DAS: A centralised system that pulls in operator signals and redistributes them via fibre/coax to many indoor antennas. Great for large airports where uniform coverage is needed.
• Leaky feeder cables: Special coax that acts like a long antenna, “leaking” RF along tunnels so trains and platforms receive consistent signal. Common in metros and long airport service tunnels.
• Handoffs: Your device measures signal quality and the network commands a move to a better cell. In dense or poorly tuned systems, handoffs can fail, causing drops. Staying still during calls helps.

Fast setup steps (iOS and Android)

• Force Wi‑Fi calling
• iOS: Control Centre > enable Airplane Mode > turn Wi‑Fi back on > ensure “Wi‑Fi” shows in the Phone app status line.
• Android: Quick Settings > Airplane Mode > enable Wi‑Fi; confirm Wi‑Fi calling icon in the dialler or status bar.
• Lock to LTE temporarily
• iOS: Settings > Mobile Data > Voice & Data > 4G.
• Android: Settings > Network & Internet > Mobile network > Preferred network type > LTE/4G.
• Switch networks
• iOS: Settings > Mobile Data > Network Selection > turn off Automatic and pick another partner.
• Android: Settings > Mobile network > Network operators > Search networks.

Pro tip: After leaving the airport or surfacing from the metro, return to Automatic network selection and 5G Auto.

FAQs

• Why do I have full bars but no data in an airport?
• Indoor systems can show strong signal but be congested on the backhaul or uplink. Try switching to 4G/LTE, move to a quieter spot, or use airport Wi‑Fi with Wi‑Fi calling.
• Does 5G work underground?
• Often only low‑band 5G or 4G is deployed in tunnels. High‑band 5G (especially mmWave) struggles with penetration and is rare below ground.
• Will Wi‑Fi calling charge me roaming fees?
• Wi‑Fi calling uses the internet, not cellular roaming, but call billing depends on your home operator. For data, airport Wi‑Fi is typically free or time‑limited. Using a local eSIM avoids surprises.
• Can I rely on emergency calls without mobile coverage?
• Your phone will try any available cellular network for an emergency call. It may also attempt the call over Wi‑Fi if supported. This is common but not guaranteed everywhere.
• Why does my battery drain faster in terminals and tunnels?
• Phones boost transmit power and scan more aggressively when signal is weak. Use Low Power Mode, keep a power bank handy, and prefer Wi‑Fi when available.
• Should I turn off 5G to save battery indoors?
• Sometimes. If 5G is weak or inconsistent, locking to 4G can stabilise connectivity and reduce scanning.

The bottom line

Airports and underground systems are challenging radio environments. Expect reflections, rapid handoffs, and capacity crunches—then prepare accordingly: enable Wi‑Fi calling, carry a multi‑network eSIM, download essentials for offline use, and know a few quick toggles to recover service when it falters. With the right setup, you’ll get your boarding pass, message your pickup, and place calls even when your bars dip.

Next step: Choose a regional plan that keeps you covered across borders and terminals. Start with Esim Western Europe.

Travellers often juggle two priorities: staying reachable on their usual number and getting affordable, fast data abroad. Dual‑SIM (physical + eSIM or dual eSIM) makes that easy—if you set it up right. This guide shows you how to control which SIM handles voice, SMS and data, how to avoid accidental roaming charges, and how to keep apps like WhatsApp and banking OTPs working smoothly. We’ll cover iOS and Android step‑by‑step, explain default line rules, and share practical roaming presets you can apply in seconds. You’ll also find app‑specific tips and troubleshooting for common snags.

If you’re new to travel eSIMs, browse country and regional options on Destinations, including ready‑to‑go packs such as Esim United States, Esim France, Esim Italy, Esim Spain, Esim Western Europe and Esim North America. Then use the dual sim data switching best practices below to keep costs down and coverage up.

What “data steering” means on your phone

Dual‑SIM data steering refers to how your device chooses a SIM for internet access, calls and messages, and whether it can switch between SIMs automatically. Key concepts:

• Default voice line: which SIM handles outgoing calls by default.
• Default SMS line: which SIM sends texts by default.
• Default data line: the only SIM that carries mobile data at any one time.
• “Allow mobile data switching” (iOS) / “Auto data switch” (Android): optionally lets the phone use the non‑data SIM for data during a call or when signal is poor.
• Data roaming per SIM: separate toggles to allow data outside your home network.
• Wi‑Fi assist / smart network switch: uses mobile data when Wi‑Fi is weak—useful, but can burn through data if you’re not careful.

Your goal as a traveller is usually to keep your home SIM active for calls/SMS, and use a local/eSIM for data—without letting the phone sneak data onto the wrong SIM.

Quick presets for travellers

Apply these simple presets to avoid bill shock and keep everything working:

• Pre‑trip 1. Install and label your travel eSIM. 2. Update apps and download offline maps on Wi‑Fi. 3. Confirm roaming SMS/call rates on your home SIM; disable data roaming on it.
• On landing 1. Set the travel eSIM as your default data line. 2. Leave your home SIM as the default for calls and SMS. 3. Turn OFF any auto data switching features to lock data to the travel eSIM. 4. Turn ON data roaming on the travel eSIM only.
• While travelling
• Keep Wi‑Fi Assist/Smart switch OFF unless you intentionally want mobile data to supplement weak Wi‑Fi.
• Use Low Data/Data Saver modes to reduce background usage.
• If you need tethering, enable Personal Hotspot on the travel eSIM.
• Flying home
• Switch default data back to your home SIM.
• Turn OFF data roaming on the travel eSIM (or disable the eSIM profile).

iOS: step‑by‑step dual sim data switching

Applies to iPhone XS and newer with Dual SIM (physical + eSIM or dual eSIM).

1) Install and label your eSIM - Settings > Mobile Data > Add eSIM. - Label each plan (e.g., “Home” and “Travel”). Accurate labels reduce mistakes later.

2) Set default voice and SMS lines - Settings > Mobile Data > Default Voice Line: choose “Home”. - Settings > Messages > Send & Receive: ensure your home number is ticked. If you also use your Apple ID email, you can send/receive iMessages without relying on SMS activation.

3) Choose your default data line - Settings > Mobile Data > Mobile Data: select “Travel”. - Mobile Data Options > Data Roaming: ON for Travel; OFF for Home.

4) Control automatic data switching - Settings > Mobile Data > Allow Mobile Data Switching: - OFF if you want to lock data to the Travel eSIM and avoid accidental home‑SIM data. - ON only if you need data continuity during voice calls on the home SIM and you’re comfortable with potential switching. If you enable it, double‑check that data roaming stays OFF on the home SIM.

5) Optimise data usage - Settings > Mobile Data > Mobile Data Options: - Data Mode: Low Data Mode to reduce background tasks. - Voice & Data: 5G Auto or LTE; switch to LTE if 5G is patchy or draining battery. - Settings > Mobile Data > Wi‑Fi Assist: OFF to prevent surprise usage when Wi‑Fi is weak.

6) Hotspot and tethering - Settings > Personal Hotspot: enable if your travel plan supports it. Hotspot uses the current default data line.

7) If data doesn’t work - Check APN: Settings > Mobile Data > your Travel plan > Mobile Data Network. Enter APN provided by your eSIM supplier if not auto‑filled. - Toggle Airplane Mode, then back. - Manually select a network: Settings > Mobile Data > Network Selection (turn off Automatic if needed and try another partner).

Recommended iOS roaming preset - Default Voice Line: Home - SMS/iMessage: Home (plus Apple ID email if you like) - Mobile Data: Travel - Data Roaming: ON (Travel), OFF (Home) - Allow Mobile Data Switching: OFF - Wi‑Fi Assist: OFF - Data Mode: Low Data Mode

Android: step‑by‑step dual sim data switching

Android menus vary. Below are common paths for Google Pixel (stock Android) and Samsung; other brands are similar.

Pixel (Android 13+) 1) Install eSIM - Settings > Network & internet > SIMs > + Add SIM.

2) Labels and defaults - Settings > Network & internet > SIMs: - Calls: set “Home” as preferred for calls. - SMS: set “Home” as preferred for texts. - Mobile data: set “Travel” as preferred.

3) Roaming and switching - Tap each SIM > Roaming: - Travel: ON; Home: OFF. - Look for “Auto data switching” or similar. If present, set OFF to avoid the phone using your home SIM for data.

4) Data controls - Settings > Network & internet > Internet > Data Saver: ON. - Turn off features like “Switch to mobile data automatically” if offered by your OEM.

Samsung (One UI 5+) 1) Install eSIM - Settings > Connections > SIM manager > Add eSIM.

2) Defaults - Settings > Connections > SIM manager: - Preferred SIMs: Calls = Home; Text messages = Home; Mobile data = Travel.

3) Roaming and switching - Tap each SIM > Data roaming: Travel ON; Home OFF. - “Switch data during calls” or “Auto data switch”: set OFF to prevent unintended use of home data. - “Dual SIM always on” handles call reachability via call forwarding; it can add costs and doesn’t affect data. Use only if you understand your operator’s charges.

4) Data controls - Settings > Connections > Data usage > Data saver: ON. - “Switch to mobile data/Wi‑Fi assist” under Wi‑Fi Advanced: consider OFF to avoid surprise usage.

Recommended Android roaming preset - Calls/SMS: Home - Mobile data: Travel - Data roaming: ON (Travel), OFF (Home) - Auto data switching: OFF - Data Saver: ON

App‑specific tips: WhatsApp, OTPs and more

WhatsApp - Your WhatsApp account is tied to your phone number, not the data SIM. You can keep WhatsApp registered to your home number while using data from your travel eSIM. - If WhatsApp needs re‑verification while abroad, you’ll need access to your home number via SMS or voice call. Keep your home SIM active for SMS (data roaming can remain OFF). - Don’t tap “Change Number” unless you truly want to move your account to a new number.

Banking OTPs and 2FA - Many banks send OTPs via SMS to your home number. Keep the home SIM active with data roaming OFF so SMS can still arrive. - If your bank supports app‑based codes or a token, set that up before travel to reduce SMS dependence.

iMessage and FaceTime - iMessage can use your Apple ID email as well as your number. In Settings > Messages > Send & Receive, tick your email to keep iMessage working even if your number can’t re‑activate. - If iMessage/FaceTime tries to re‑activate using SMS, ensure your home SIM can receive SMS.

Android RCS (Chat features) - Google Messages’ RCS is associated with a specific number/SIM. You can keep RCS on your home number while mobile data comes from the travel eSIM—just ensure the home SIM remains active, and RCS is registered before you go.

One‑time passwords from services - Expect some OTPs to arrive via SMS with delays when roaming. Have backup methods (authenticator app, email, or app approval) where available.

Troubleshooting and pro tips

• Lock data to the correct SIM: Turn OFF “Allow Mobile Data Switching” (iOS) or “Auto data switch” (Android) during travel.
• Check APN settings: If data connects but is slow or drops, verify APN is auto‑filled per your eSIM instructions.
• Manually change networks: In some countries, one partner network is faster. Try manual network selection on the travel eSIM.
• Prefer LTE when 5G is patchy: Switching to LTE can improve stability and battery life.
• Only one data SIM at a time: Dual‑SIM Dual Standby means two lines are active for calls/SMS, but only one can carry mobile data.
• Background data control: Use Low Data Mode (iOS) or Data Saver (Android). Consider restricting heavy apps to Wi‑Fi.
• Hotspot with care: Tethering uses your default data SIM; verify your plan allows it.
• Frequent flyers: Keep a “Travel” profile ready to toggle—data to Travel, data roaming OFF on Home, auto switching OFF.
• Regional eSIMs: Multi‑country options like Esim Western Europe or Esim North America reduce mid‑trip SIM shuffling. For single‑country trips, pick Esim United States, Esim France, Esim Italy or Esim Spain.

For teams and frequent travellers

If you manage staff on the road, set a standard preset: home SIM for calls/SMS, travel eSIM for data, roaming OFF on home SIM, and auto data switching disabled. Provide a simple runbook for iOS and Android.

• Centralise procurement and control with pooled eSIMs and usage reporting via For Business.
• If you’re a reseller or travel partner, explore co‑branded solutions through our Partner Hub.

FAQ

• Will changing the data SIM affect my phone number for calls or WhatsApp?
• No. Your phone number for calls/SMS stays on the SIM you set for voice. WhatsApp remains tied to the number it was registered with, regardless of which SIM provides data.
• Can I receive SMS on my home SIM with data roaming off?
• Yes. SMS uses the signalling channel, not mobile data. Keep the home SIM active and data roaming OFF to receive texts without using mobile data.
• Should I enable “Allow Mobile Data Switching” on iPhone while abroad?
• Usually no. Keep it OFF to prevent accidental data usage on your home SIM. Enable only if you need uninterrupted data during calls and you’re confident your home SIM won’t incur data charges.
• My travel eSIM shows signal but no data. What now?
• Toggle Airplane Mode, check APN, and ensure Data Roaming is ON for the travel eSIM. Try manual network selection to pick an alternative partner.
• Can I hotspot from my travel eSIM and still receive calls on my home number?
• Yes. Personal Hotspot uses the current default data line (travel eSIM), while your home SIM remains active for calls and SMS.
• Does my phone auto‑switch data to the “better” SIM when signal is poor?
• Only if you enable features like “Allow Mobile Data Switching” (iOS) or “Auto data switch” (Android). For cost control while roaming, keep these OFF.

Next step: Pick your destination and get a travel eSIM that fits your trip on Destinations, then apply the presets above before you fly.

Travelling often means bouncing between hotel Wi‑Fi, café hotspots and mobile data. Each network you join can see, intercept or manipulate your DNS — the phone book lookups your device makes to turn website names into IP addresses. That’s where Private DNS (encrypted DNS) comes in. It wraps those lookups in encryption (DNS over TLS or DNS over HTTPS) so intermediaries can’t snoop or tamper. The result: cleaner, more private browsing with little to no speed penalty.

This guide explains how private DNS works, when to use it versus a VPN, and exactly how to enable it on Android, iOS/iPadOS, Windows and macOS. We’ll also cover captive portal “sign‑in” gotchas in hotels and airports, battery impact, and which DNS providers are worth trusting on the road. Combine private DNS with a local eSIM and you’ll avoid flaky public Wi‑Fi entirely in many destinations — see our regional options on Destinations including Esim United States, Esim France, Esim Italy, Esim Spain, Esim Western Europe and Esim North America.

What is Private DNS and why travellers should care

• DNS translates website names into IP addresses. By default, these lookups are unencrypted and readable by anyone running the network you’re on (hotel, café, airport).
• Private DNS encrypts those lookups:
• DNS over TLS (DoT): DNS inside a TLS tunnel on port 853 (Android’s “Private DNS” uses DoT).
• DNS over HTTPS (DoH): DNS inside standard HTTPS on port 443 (supported in Windows 11 and via apps on iOS/macOS).
• Benefits:
• Stops local network operators from snooping your browsing destinations.
• Blocks simple DNS‑level ads/malware if you choose a provider that offers filtering.
• Reduces risk of DNS hijacking on hostile or misconfigured networks.

Limits to understand: - Private DNS does not hide your IP address or encrypt the rest of your traffic — the websites you visit still see your IP, and the network can see the IPs you connect to. For that, use a VPN. - It may interfere with captive portals (those “agree & connect” pages) — easy to work around; see below.

Private DNS vs VPN: which should you use on the road?

• Use Private DNS when:
• You want lightweight privacy without changing location or routing all data.
• You’re on mobile data (eSIM/local SIM) and mainly need DNS protection.
• You want minimal battery and speed impact.
• Use a VPN when:
• You’re on untrusted public Wi‑Fi and doing sensitive tasks (banking, work logins).
• You need to access corporate resources or a specific country’s services.
• You must protect all traffic metadata, not just DNS.

Pro tip: On mobile networks, TLS in apps (HTTPS) already secures content. Pairing that with Private DNS covers the main leak (DNS) without the heavier overhead of a VPN.

How to enable Private DNS on your devices (How‑To)

Android 9 and newer (DoT)

Most modern Android devices support system‑wide Private DNS (DNS over TLS).

1) Open Settings > Network & Internet (or Connections on Samsung). 2) Tap “Private DNS”. 3) Choose “Private DNS provider hostname”. 4) Enter one provider hostname (examples): - Cloudflare: 1dot1dot1dot1.cloudflare-dns.com - Google: dns.google - Quad9 (malware blocking): dns.quad9.net - AdGuard (ad/malware filtering): dns.adguard.com 5) Save and reconnect to your network.

Notes: - “Automatic” tries encrypted DNS only if your current DNS supports DoT; “Off” reverts to unencrypted DNS. - If a captive portal won’t load, temporarily set Private DNS to “Off”, sign in, then switch it back on.

Pro tip: Quad9 is a strong travel choice for malware/phishing protection without logging personal data.

iPhone and iPad (iOS 14+ via profile or app)

iOS doesn’t have a one‑tap system setting for encrypted DNS. Use a trusted DNS app or configuration profile.

Option A — Cloudflare or NextDNS app: 1) Install the “Cloudflare 1.1.1.1” app or the “NextDNS” app from the App Store. 2) Open the app, grant permission to add a VPN/DNS configuration (this is a local device profile, not a full VPN tunnel for Cloudflare’s “DNS only” mode). 3) Enable “DNS‑only” mode (Cloudflare “1.1.1.1” without Warp) or choose your NextDNS profile. 4) Leave the app enabled; it will enforce DoH across apps.

Option B — Install an encrypted DNS profile: 1) Create a profile with a provider (e.g., NextDNS web dashboard). 2) Download and install the mobile configuration profile in Settings > General > VPN & Device Management. 3) Verify the profile is active.

Captive portal tip: Toggle the DNS app off, complete the Wi‑Fi sign‑in, then re‑enable.

Windows 11 (DoH)

1) Settings > Network & Internet > Wi‑Fi (or Ethernet) > Hardware properties. 2) Edit DNS server assignment > Manual. 3) Enable IPv4 (and IPv6 if you use it). 4) Enter DNS addresses (e.g., 1.1.1.1 and 1.0.0.1 for Cloudflare; 9.9.9.9 and 149.112.112.112 for Quad9). 5) Set “Preferred DNS encryption” to “Encrypted only (DNS over HTTPS)”. 6) Save. Reconnect to the network.

Quick verify: Visit your provider’s test page (e.g., Cloudflare’s “Help” page) to confirm DoH is active.

macOS (Big Sur and newer)

macOS supports encrypted DNS via configuration profiles or apps.

Option A — Use an app (simplest): 1) Install Cloudflare 1.1.1.1 or NextDNS app for macOS. 2) Grant permissions to add a DNS profile. 3) Enable DNS‑only mode (Cloudflare) or your NextDNS configuration.

Option B — Install a DNS profile: 1) Generate a DoH/DoT profile from your provider (e.g., NextDNS). 2) Install via System Settings > Privacy & Security > Profiles (or Profiles in System Preferences on older macOS). 3) Apply to active network services.

Captive portal tip: Pause the app/profile temporarily to complete hotel/airport sign‑in pages.

Captive portals: the gotcha and the fix

Encrypted DNS can prevent captive portals from redirecting you to the sign‑in page because the network expects to intercept DNS. Here’s how to handle it smoothly:

• Join the Wi‑Fi network.
• If the login page doesn’t appear within 10 seconds:
• Android: Settings > Network & Internet > Private DNS > Off. Then re‑open your browser and go to http://neverssl.com to trigger the portal.
• iOS/macOS: Pause your DNS app/profile. Try http://neverssl.com or open the Wi‑Fi network’s info and tap “Join Network”/“Login”.
• Windows: Temporarily switch encryption to “Unencrypted only” or disable your DNS tool; reconnect and sign in.
• Once you’re online, re‑enable Private DNS.

Pro tips: - Some networks re‑check the portal after idle time; keep the DNS tool handy to toggle. - If the portal still won’t load, “Forget” the network and try again with Private DNS off until authenticated.

Will Private DNS slow me down or drain battery?

Speed: - The overhead of DoT/DoH is tiny after the first handshake. With anycast networks (Cloudflare, Google, Quad9), latency is comparable to or better than many hotel DNS servers. - DoH may add a fractionally higher CPU cost than plain DNS, but it’s negligible on modern devices. - Pick a nearby, reputable provider to avoid detours.

Battery: - Private DNS maintains lightweight encrypted sessions; the impact is minimal, far less than a full VPN. - VPNs keep an always‑on tunnel with regular keep‑alive traffic and packet processing — expect noticeably higher battery drain. - On mobile data, modern radios dominate battery use; private DNS won’t be the deciding factor.

Testing tip: Use a DNS benchmark app or “dig” from a laptop tethered to your phone to compare latency before and after.

Choosing a trusted DNS provider

Look for a clear privacy policy, broad global footprint, and (if desired) security filtering:

• Cloudflare (1.1.1.1): Fast, strong privacy stance, no content filtering by default. DoT: 1dot1dot1dot1.cloudflare-dns.com. DoH supported widely.
• Google (8.8.8.8): Globally fast and reliable; transparent but different privacy model from Cloudflare.
• Quad9 (9.9.9.9): Security‑focused with threat blocking, non‑profit; strong choice for travellers wanting extra protection.
• AdGuard DNS: Optional ad/malware blocking; privacy‑friendly.
• NextDNS: Highly configurable filtering, logs you control; requires a personalised profile.

Pro tip: For family devices, NextDNS/AdGuard can block trackers and malicious domains while travelling, reducing risky clicks on unfamiliar networks.

A practical travel checklist

Before you fly: - Update your device OS and apps (security patches). - Set up Private DNS or install your DNS app/profile. - Save provider hostnames or app toggles for quick captive portal workarounds. - Add a lightweight VPN for when you must trust public Wi‑Fi. - Consider a local eSIM so you can skip public Wi‑Fi altogether; browse regional options on Destinations — including Esim Western Europe and Esim North America.

On the day: - Prefer mobile data where possible. If you’re heading to the US or Europe, check Esim United States, Esim France, Esim Italy and Esim Spain. - On Wi‑Fi, enable Private DNS; toggle off only briefly for captive portals. - Use a VPN for banking or work portals on public Wi‑Fi. - Avoid installing random “Wi‑Fi booster” apps; stick to reputable DNS/VPN tools.

For teams and partners: - Business travellers can standardise encrypted DNS and eSIMs through our For Business solutions. - Travel providers and IT resellers can collaborate via our Partner Hub.

When you still need a VPN (even with Private DNS)

• Accessing corporate networks or region‑locked services where location matters.
• Using truly untrusted or tampered networks (e.g., conferences, shared coworking).
• Hiding destination IP metadata from local network operators.
• Enforcing security policies across all traffic for a business fleet.

Private DNS protects DNS queries; a VPN protects the entire session. It’s fine to run both when needed — start with Private DNS by default, escalate to VPN for sensitive sessions.

FAQ

• Does Private DNS change my location like a VPN?
• No. It only encrypts DNS lookups. Your IP address and approximate location remain the same.
• Will Private DNS break streaming or apps while travelling?
• Rarely. Some hotel or airline networks require their own DNS; if something fails, temporarily switch Private DNS off, then back on after login/stream start.
• Is DoT or DoH better for travel?
• Both are secure. Use what your device supports natively: Android prefers DoT; Windows 11 uses DoH. Performance differences are negligible.
• Can I use Private DNS on cellular data with an eSIM?
• Yes. It works on any network type. Pairing Private DNS with a local eSIM gives private, fast lookups without relying on risky public Wi‑Fi. See regional options on Destinations.
• Which DNS provider should I pick?
• For speed and privacy: Cloudflare or Google. For added threat protection: Quad9. For custom filtering/log control: NextDNS. Stick to one you trust.
• Does Private DNS save battery compared to a VPN?
• Yes. It has a much smaller battery impact because it encrypts only DNS, not all traffic.

Next step: Set up Private DNS on your devices today, then choose a local eSIM for your next trip on Destinations so you can rely on mobile data instead of risky public Wi‑Fi.

Travelling with a finite data allowance can be stressful—especially when maps, ride‑hailing, translation, and social apps all quietly sip from your gigabytes. The good news: you can reduce data usage travel‑wide without making your phone unusable or turning your photos into postage stamps. The trick is a layered approach: start with your phone’s OS‑level data saver, then tame background sync, set sensible quality for maps and streaming, and choose compression or “lite” modes where it counts. Do this once before you fly, and you’ll cut consumption by 30–70% while keeping the essentials fast and clear. Below you’ll find practical step‑by‑steps for iPhone and Android, app‑level switches that deliver the biggest wins, and a simple routine to keep you in control for the rest of your trip. If you need more data for a road trip or work, we also point you to regional eSIMs so you’re never caught short.

Why data disappears faster abroad

Roaming highlights how “chatty” smartphones are by default. Common culprits:

• Background app refresh, inbox syncing, and cloud photo backups
• HD video auto‑play in social feeds
• High‑resolution map tiles and live traffic
• App and OS updates, and automatic photo/video uploads
• Tethered laptops pulling down system updates and cloud files

Combine these with patchy hotel Wi‑Fi and you’ve got a perfect storm. The fix: constrain background activity, right‑size media quality, and pre‑download on Wi‑Fi.

Step 1: Enable OS‑level Data Saver

Your phone’s built‑in data saver is the single biggest switch to reduce data usage travel‑wide. It prioritises foreground tasks and reins in background sync.

Android: Turn on Data Saver and whitelist essentials

1. Settings > Network & Internet (or Connections) > Data Saver.
2. Toggle Data Saver On.
3. Tap Unrestricted data (or “Unrestricted apps”) and allow only the must‑haves (e.g., maps, ride‑hailing, authenticator, airline app).
4. Optional: Settings > Network & Internet > SIMs > Data usage > set a warning and a hard limit.

Pro tips: - In Chrome: Settings > Privacy & security > Preload pages > No preloading (stops prefetching data you might not read). - Many Android skins let you disable auto‑sync globally under Accounts & backup. Use sparingly; whitelist what you genuinely need.

iPhone: Use Low Data Mode on mobile and Wi‑Fi

1. Settings > Mobile Data > Mobile Data Options > Data Mode > Low Data Mode.
2. For Wi‑Fi networks: Settings > Wi‑Fi > “i” next to the network > Low Data Mode On.
3. Settings > App Store > Automatic Downloads: Off (or Mobile Data Off). Optional: turn off Video Autoplay.

Pro tips: - iPhone doesn’t have per‑app whitelisting for Low Data Mode, so individually disable Mobile Data for apps you don’t need: Settings > Mobile Data > toggle apps Off. - Disable Background App Refresh for non‑essential apps: Settings > General > Background App Refresh > Off for specific apps (or Wi‑Fi only).

Step 2: Control background sync and cloud uploads

These run silently and can devour hundreds of MB per day if left unchecked.

Checklist (Android and iPhone): - Email: Set to manual or longer fetch intervals. - iPhone: Settings > Mail > Accounts > Fetch New Data > Push Off; set Fetch to Hourly or Manual. - Android (Gmail): Gmail app > Menu > Settings > your account > Data usage > Sync Gmail Off (or limit labels). - Photos backup: - Google Photos: Profile > Photos settings > Backup > Mobile data usage Off (or limited). Enable “Back up only while charging” if offered. - iCloud Photos: Settings > Photos > Mobile Data Off; consider pausing Shared Library sync. - Messaging/media auto‑download: - WhatsApp: Settings > Storage and Data > Media auto‑download > set all to Wi‑Fi; toggle “Use less data for calls” On. - Telegram: Settings > Data and Storage > set auto‑download limits for Mobile Data to Low or None. - iMessage: Settings > Messages > Low Quality Image Mode On (sends smaller photos). - App updates: - Play Store: Profile > Settings > Network preferences > Auto‑update apps > Over Wi‑Fi only. - App Store: Settings > App Store > App Updates Off (or Mobile Data Off).

Pro tip: - Turn off “Wi‑Fi Assist” (iPhone: Settings > Mobile Data > Wi‑Fi Assist Off) so your phone doesn’t silently switch to mobile data when hotel Wi‑Fi stutters.

Step 3: Optimise maps and navigation

Maps are essential on the road, but live tiles and satellite layers consume data quickly. Pre‑download and run lean during the day.

Google Maps (Android/iOS)

1. On Wi‑Fi, open Google Maps > profile photo > Offline maps.
2. Tap Select your own map > zoom to cover your trip region > Download.
3. Settings > Offline maps > Auto‑update Over Wi‑Fi only.
4. During navigation, avoid Satellite view and 3D. Traffic uses modest data; keep it if you need it.

Apple Maps (iOS 17+)

1. On Wi‑Fi, Apple Maps > your profile image > Offline Maps > New Map.
2. Select the region > Download. Toggle “Only download over Wi‑Fi”.
3. While travelling, prefer offline routes; traffic and transit updates may require mobile data.

Pro tips: - Save must‑visit places to a list before you go; cached details reduce lookups. - Ride‑hailing: Keep mobile data on for those apps only. They’re time‑sensitive and low‑volume compared to video.

Step 4: Stream smarter (video, music, social)

Right‑sizing quality saves most of the heavy lifting while staying watchable.

Video

• YouTube: Profile > Settings > Video quality preferences > On mobile networks: Lower picture quality. Consider 480p for travel days.
• Netflix: App > Menu > App Settings > Cellular Data Usage > Save Data. Downloads: set to Standard and pre‑download shows on Wi‑Fi.
• Disney+/Prime/others: Look for “Data Saver” or set Mobile Streaming to Medium/Standard.
• Rough guide:
• 1080p uses ~3–7 GB per hour;
• 720p ~1.5–3 GB per hour;
• 480p ~0.7–1 GB per hour. Downgrading from 1080p to 480p can save 70–85%.

Music and podcasts

• Spotify: Settings > Audio Quality > Streaming: Low/Normal on Mobile; Downloads: Normal. Toggle “Download using cellular” Off.
• Apple Music: Settings > Music > Mobile Data Off; or set Audio Quality > Streaming: High Efficiency on Mobile.
• Podcasts: Download episodes on Wi‑Fi only and disable “Allow Over Mobile Data”.

Social apps

• Instagram: Settings > Data usage and media quality > Use less mobile data On; High‑quality uploads Off; Auto‑play videos On Wi‑Fi only.
• TikTok: Settings and privacy > Data Saver On; limit HD downloads.
• Facebook/Twitter/X: Disable auto‑play videos on mobile and set image upload quality to standard.

Pro tip: - Batch‑download playlists and episodes on hotel Wi‑Fi each night; you’ll cruise through the next day with minimal mobile usage.

Step 5: Browse with compression and “lite” modes

Modern sites are heavy. A few tweaks lighten the load:

• Opera/Opera Mini: Enable Data Savings/Compression to proxy and compress images, scripts, and videos—often 40–90% savings for browsing.
• Chrome (Android): Settings > Privacy & security > Preload pages > No preloading (stops background fetch).
• Reader Mode: Safari/Firefox Reader strips ads and scripts on articles, loading mostly text and a few images.
• Block auto‑play: In Safari (iOS), Settings > Accessibility > Motion > Auto‑Play Video Previews Off.

Pro tip: - If a site offers a “lite”, “basic” or AMP version, favour it on mobile data.

Step 6: Be careful when tethering laptops

Laptops can burn through a day’s allowance in minutes.

• Windows: Settings > Network & Internet > your mobile network > Set as metered connection On. Pause Windows Update and OneDrive sync.
• macOS: System Settings > Software Update > Automatic updates Off (temporarily). Photos > iCloud > Pause iCloud Photos. Disable Dropbox/OneDrive sync.
• Browsers: Disable auto‑play and heavy extensions. Save large downloads for Wi‑Fi.

Pro tip: - When possible, use the mobile app instead of the desktop site; mobile apps are often more data‑efficient for the same task.

Step 7: Measure and cap usage

Track what’s actually consuming your data and adjust.

• Android: Settings > Network & Internet > SIMs/Data usage > View per‑app usage; set warnings and limits.
• iPhone: Settings > Mobile Data > scroll for per‑app usage. Reset statistics at the start of your trip and review mid‑trip. Disable Mobile Data per app for hogs.

Pro tip: - If you’re hotspotting, use your phone’s built‑in usage graph and the laptop’s metered settings together to stay under budget.

When to pick a bigger plan (and where to get it)

Even perfectly optimised settings can’t compress a navigation‑heavy road trip plus daily video calls. If your itinerary includes long drives, remote work, or family streaming, choose a plan with headroom:

• Planning a multi‑country jaunt? See Esim Western Europe for one pass across borders.
• City‑hopping in Italy, France or Spain? Check country packs: Esim Italy, Esim France, Esim Spain.
• Crossing the pond? Compare Esim North America and single‑country options like Esim United States.
• Browse all covered countries on Destinations.
• Travelling as a team or on expensed trips? Centralise and control usage with For Business. Partners and resellers can explore the Partner Hub.

Quick “pre‑flight” checklist to reduce data usage travel‑wide

• Turn on Data Saver/Low Data Mode (mobile and Wi‑Fi).
• Set app and OS updates to Wi‑Fi only.
• Pre‑download offline maps for your route.
• Set video to 480p/“Data Saver”; music to Normal/Low on mobile.
• Disable auto‑play videos in social apps; limit media auto‑download in messengers.
• Pause cloud photo backups on mobile data.
• Set hotspot laptops to “metered” and pause large syncs/updates.
• Add Android data warning/limit or reset iPhone data counters.

FAQ

1) Will Data Saver affect call quality or WhatsApp calls? - Regular voice calls are unaffected. VoIP calls (WhatsApp/FaceTime Audio) use roughly 0.2–0.7 MB per minute. Data Saver may reduce background traffic, which can improve call stability on weak connections. In WhatsApp, enable “Use less data for calls” for extra savings.

2) Do VPNs save data through compression? - Most consumer VPNs don’t reduce usage; encryption prevents proxy‑style compression. A few “accelerator” services compress images, but benefits are app/site‑dependent. Rely first on OS Data Saver and in‑app quality controls.

3) Can I get live traffic when using offline maps? - Yes, but only when you have a data connection. Offline maps give you routing and POIs without data. Traffic overlays and real‑time rerouting require some connectivity; they’re modest in volume compared to streaming.

4) How much do I save dropping video from 1080p to 480p? - Typically 70–85% per hour. Expect ~3–7 GB/h at 1080p vs ~0.7–1 GB/h at 480p, depending on the platform and codec.

5) Best way to tame Instagram and TikTok on the road? - Turn on each app’s Data Saver, disable high‑quality uploads, and set video auto‑play to Wi‑Fi only. Limit background refresh and consider downloading stories/reels on Wi‑Fi if supported.

6) Should I switch off 5G to save data? - 5G itself doesn’t use more data, but faster speeds can encourage heavier consumption (pages and videos load sooner at higher quality). If you find yourself burning through data, keep 5G but lock video quality and disable preloading/auto‑play.

Next step: Choose the right regional eSIM with enough headroom for your trip on Destinations, then apply the settings above before you fly.

Travelling with an eSIM should be quick and painless, but the jargon around SM‑DP+, LPA and EID can make activation feel more complex than it really is. This guide demystifies the moving parts so you can install, recover or move your eSIM profile with confidence—whether you’re scanning a QR code at the airport or entering details manually on a long‑haul flight. We’ll compare activation methods (QR vs manual), explain where each code lives and what it does, walk through recovery steps if you delete or change phones, and share tips for transferring your plan to a new device. You’ll also find practical troubleshooting for common activation errors and a traveller‑ready checklist to avoid surprises abroad. If you’re heading to the USA, Europe or beyond, we’ve included links to regional plans so you can choose your coverage and get online fast.

The building blocks: SM‑DP+, LPA and EID explained

If you remember only one line from this article, make it this: the LPA on your phone uses your EID to fetch an eSIM profile from an SM‑DP+ server. That’s the whole “smdp+ eid esim” flow in a nutshell.

SM‑DP+ (Subscription Manager – Data Preparation)

• Think of SM‑DP+ as the secure server where your eSIM profile is prepared and hosted.
• During manual activation, you enter the SM‑DP+ address and an activation code so your phone knows where to download from and which profile to fetch.
• This is usually embedded inside the QR code; manual entry is the back‑up when you can’t scan.

LPA (Local Profile Assistant)

• The LPA is the software on your device (within iOS/Android) that manages eSIM tasks: downloading, installing, enabling, disabling and deleting profiles.
• When you scan a QR or enter details, the LPA talks to the SM‑DP+ server to securely download your profile.

EID (eUICC Identifier)

• The EID uniquely identifies your phone’s eSIM chip (like a serial number for the eUICC).
• Providers sometimes need your EID to push a profile or to re‑enable a download.
• Where to find it:
• iPhone: Settings > General > About > EID
• Pixel/Android: Settings > About phone > Status (or SIMs/eSIM details) > EID
• Samsung: Settings > Connections > SIM manager > eSIM > EID

Pro tip: Note your EID before you travel. If something goes wrong mid‑journey, support can help faster.

Activation methods compared: QR vs manual vs carrier app

Most travellers activate by scanning a QR code, but manual entry of SM‑DP+ + activation code is a robust fallback. Some devices and providers also support app‑based activation.

Method 1: QR code (fastest for most travellers)

• What you need: Stable Wi‑Fi (recommended), the printed/digital QR, and your device unlocked.
• iPhone (iOS 17+): 1. Settings > Mobile Data/Cellular > Add eSIM 2. Tap Use QR Code and scan 3. Follow prompts to label the line and set default for data
• Android (Pixel): 1. Settings > Network & Internet > SIMs > + Add SIM > Download a SIM instead 2. Scan the QR and confirm
• Samsung (One UI 6): 1. Settings > Connections > SIM manager > Add eSIM 2. Scan the QR and install

Pro tips: - Install over Wi‑Fi before you fly to avoid airport Wi‑Fi congestion. - If the camera refuses to scan, increase screen brightness or use manual entry.

Method 2: Manual SM‑DP+ + activation code

• What you need: The SM‑DP+ server address and an activation code (sometimes a confirmation code too).
• iPhone: 1. Settings > Mobile Data/Cellular > Add eSIM 2. Tap Enter Details Manually 3. Enter SM‑DP+ address and activation code; add confirmation code if requested
• Android: 1. Go to Add eSIM (as above) 2. Choose Enter activation code or Enter details manually 3. Enter SM‑DP+ address and activation code

Pro tips: - If you see “No valid SM‑DP+” check for typos, hidden spaces or dashes. - Keep the activation email/PDF offline. Airplane mode plus Wi‑Fi is fine; you don’t need a physical SIM to install an eSIM.

Method 3: Carrier or device app

• Some providers push profiles directly via their app; iPhone also supports “Convert to eSIM” and “eSIM Quick Transfer”.
• App‑based activations may not work if your device is region‑locked or the app geo‑restricts downloads.

When you can’t scan: manual activation that just works

QR codes package the SM‑DP+ address and activation code into one scannable square. If the code is blurry, printed too small, or you’re viewing it on the same device you’re activating, use manual entry.

Checklist for reliable manual activation: - Wi‑Fi connected and stable - Correct SM‑DP+ server address (copy/paste carefully) - Activation code exactly as given (case sensitive in some systems) - If asked for a “confirmation code” or “SMDP+ activation code”, that’s the same field as activation code for many providers - Time/date set automatically on your phone (TLS handshakes can fail if your clock is wrong)

If you still can’t download, capture a screenshot of the error and share your EID with support. Most providers can trace the server attempt by EID and time stamp.

Recovery after deletion or SIM swap: what to expect

Deleting a profile or moving phones doesn’t always mean it’s gone for good. Your options depend on the provider’s policy and whether the plan has already been consumed.

Common scenarios and recovery steps: - You deleted the eSIM before travelling: - Many plans can be re‑downloaded to the same device. Contact support with your EID and order reference. - You changed phones: - If the provider supports re‑download to a new EID, they’ll usually ask for the new device’s EID. Some plans are single‑use only. - You reset your phone: - iCloud/Google backups do not include the eSIM profile itself. You’ll need to re‑download or transfer it. - Your QR expired: - Ask for fresh SM‑DP+ credentials. Some providers time‑box activation links.

Traveller tip: Don’t delete an eSIM until you’re certain you no longer need it (e.g., number transfer complete, data fully used, or plan expired).

Moving your eSIM to a new phone

Not all providers support transfers, but when they do, these are the cleanest paths.

iPhone to iPhone: eSIM Quick Transfer (best case)

• Requirements: iOS 16+, both devices nearby, Bluetooth/Wi‑Fi on, same Apple ID often helps.
• Steps: 1. On the new iPhone: Settings > Mobile Data/Cellular > Add eSIM 2. Tap Transfer from Nearby iPhone 3. Confirm on the old iPhone and follow prompts
• If Quick Transfer isn’t offered, use your original QR/SM‑DP+ details or contact support to re‑provision.

Android to Android: device tools vary

• Pixel: Settings > Network & Internet > SIMs > Transfer or Add eSIM (if supported)
• Samsung: Smart Switch can move eSIM on certain models/regions; otherwise use original QR/manual activation.
• If transfer isn’t available, ask the provider to re‑enable download for your new EID.

Cross‑platform (iPhone ↔ Android)

• Direct transfer isn’t supported. You’ll need re‑provisioning to the new device’s EID with fresh SM‑DP+ credentials.

Before you switch phones: - Screenshot your eSIM details (ICCID, plan label) - Note both EIDs (old and new) - Ensure the plan isn’t mid‑use with roaming critical to your trip

Dual‑SIM travel setup: do it once, do it right

• Set your travel eSIM as the Mobile Data line; keep your home SIM for calls/SMS and multi‑factor codes.
• iPhone: Settings > Mobile Data > Mobile Data > choose your eSIM; turn on Data Roaming for the eSIM only.
• Android: Settings > Network & Internet/Connections > SIMs/SIM manager > Mobile data > choose eSIM; enable Data roaming for that line.
• Keep “Allow Mobile Data Switching” off if you want to avoid your phone silently using your home SIM for data.
• APN: Most eSIMs auto‑configure. If you have no data, enter the APN from your provider’s instructions and restart.

Troubleshooting: fast fixes for common activation errors

• “Unable to complete cellular plan change”
• Toggle Airplane mode on/off, reboot, and retry on strong Wi‑Fi.
• Ensure date/time are automatic.
• “Activation code invalid”
• Check for stray spaces; try manual entry.
• Confirm the code hasn’t already been redeemed or expired.
• Stuck on “Activating”
• Switch Wi‑Fi networks (captive portals can block downloads).
• Try another location; some corporate networks block eSIM traffic.
• Installed but “No Service”
• Enable Data Roaming for the eSIM line.
• Set Network Selection to Automatic.
• Confirm the plan is valid in your country; if you’re in the USA, see regional options like Esim United States or broader Esim North America.
• Data works, calls/SMS don’t
• Your plan may be data‑only by design (common for travel eSIMs).
• Profile disappeared after update/reset
• It wasn’t backed up. Contact support with your EID for re‑provisioning options.

Picking the right footprint for your trip

Choose coverage to match your route: - Single‑country stays: e.g., Esim France, Esim Italy or Esim Spain - Multi‑country tours: Esim Western Europe simplifies roaming across borders - Transatlantic or cross‑border: Esim North America covers USA/Canada/Mexico - See all regions on Destinations

For teams on the move, centralised purchasing and fleet management are available via For Business. Travel brands and resellers can explore co‑branded or embedded flows in our Partner Hub.

Pre‑trip checklist (5 minutes)

• Confirm your phone is eSIM‑capable and unlocked
• Save your SM‑DP+ address, activation code and QR offline
• Note your EID and order number
• Install on Wi‑Fi before departure; test data once
• Label your lines clearly (e.g., “Home” and “Trip – EU”)
• Set your eSIM as the data line; enable Data Roaming for that line only

FAQ

Q1: What’s the practical difference between EID and ICCID? - EID identifies your device’s eUICC (the chip); ICCID identifies a specific eSIM profile/plan. Support might ask for both, but EID is essential for pushing or recovering a profile.

Q2: Do I need to keep the QR code after activation? - Yes. Keep the QR and SM‑DP+ details until the trip is complete. Some providers allow re‑downloads; others treat the code as single‑use.

Q3: Can I store multiple eSIMs and switch between them? - Most modern phones store several profiles (e.g., 5–10). You can enable one eSIM data line at a time, then switch in Settings. Delete only when you’re certain you’re done.

Q4: Will eSIM activation work without Wi‑Fi? - It can work on mobile data, but Wi‑Fi is more reliable—especially during initial download. Airports and hotels with captive portals can cause issues; a private hotspot is ideal.

Q5: My provider asked for my EID to “push” a profile. Is that safe? - Yes—sharing your EID is standard practice for provisioning. It lets the SM‑DP+ server target your device’s eUICC precisely.

Q6: How do QR and manual activation differ from a security standpoint? - They’re equivalent. The QR just bundles the SM‑DP+ address and activation code. Manual entry uses the same secure TLS session via the LPA.

Next step: choose your coverage and install ahead of your trip. Browse all regions on Destinations.

A full set of signal bars doesn’t always mean fast data, and a single bar doesn’t always mean you’re stranded. The real story sits behind the scenes in three radio metrics used by 4G LTE and 5G: RSRP, RSRQ and SINR. If you’re a traveller juggling maps, ride‑hailing, translation, streaming, or hotspot sharing, these numbers can tell you whether moving closer to a window, switching to LTE, or trying a different network will help. This guide goes beyond jargon to give you rsrp rsrq sinr explained in plain English, including practical thresholds for “good/OK/poor”, how buildings and city streets skew each value, and quick steps to read them on iPhone and Android. We’ll also show how to act on what you see—useful if you’re bouncing between countries in Esim Western Europe, the Esim United States, or wider Esim North America.

RSRP, RSRQ, SINR explained (really simply)

• RSRP (Reference Signal Received Power): Think “how loud is the tower’s voice at your phone”. It’s pure signal strength from the cell, measured in dBm (negative numbers; closer to zero is stronger).
• RSRQ (Reference Signal Received Quality): Think “how clearly you can hear that voice in a crowd”. It mixes strength with how busy the channel is, measured in dB (negative numbers; closer to zero is better).
• SINR (Signal to Interference plus Noise Ratio): Think “signal versus all the junk around it”. A higher positive number is cleaner. This drives your top speeds and stability.

Used together: - RSRP tells you if you’re near/far or shielded by walls. - RSRQ and SINR tell you if interference, reflections, or congestion are ruining quality.

Units and signs at a glance

• RSRP: dBm, typically −65 (excellent) to −120 (very poor). Less negative is better.
• RSRQ: dB, typically −3 (excellent) to −20 (very poor). Closer to 0 is better.
• SINR: dB, typically −10 (unusable) to 30 (excellent). Higher positive is better.

What counts as good, OK, or poor?

These are practical, field‑tested thresholds for everyday travellers on 4G LTE and sub‑6 GHz 5G. mmWave behaves differently and is extremely sensitive to blockage.

• RSRP (signal strength)
• Excellent: −80 dBm or stronger
• Good: −80 to −90 dBm
• Fair/OK: −90 to −100 dBm
• Poor: −100 to −110 dBm
• Unreliable: weaker than −110 dBm
• RSRQ (signal quality)
• Excellent: better than −10 dB (e.g., −3 to −9)
• Good: −10 to −12 dB
• Fair/OK: −12 to −15 dB
• Poor: worse than −15 dB
• SINR (clean signal vs. junk)
• Excellent: > 20 dB
• Good: 13–20 dB
• Fair/OK: 0–13 dB
• Poor: < 0 dB

Quick mental model: - High RSRP + high SINR = best speeds and stability - High RSRP + low SINR/RSRQ = close to a cell but lots of interference/congestion - Low RSRP + decent SINR/RSRQ = further away; may be stable but slower

Pro tip: When speeds are the goal (video calls, uploads), SINR is the star metric. RSRP is necessary, but SINR unlocks higher modulation and throughput.

How buildings and streets change the numbers

Why your metrics change from street to lobby to lift:

• Walls and windows reduce RSRP (strength)
• Typical losses: modern glass 2–10 dB; brick 10–20 dB; reinforced concrete 20–40 dB; metal/low‑E coated glass up to 30+ dB.
• Sub‑6 GHz 5G and 4G at lower bands (700–900 MHz) penetrate better than higher bands (1800–3500 MHz).
• Urban “canyons” hurt SINR and RSRQ (quality)
• Reflections from glass and metal create multipath. Your phone hears the same signal arriving slightly out of sync, increasing interference.
• You may see decent RSRP but poor SINR/RSRQ on busy downtown corners.
• Elevation helps—sometimes
• Higher floors near a window often improve RSRP and SINR by clearing street‑level clutter.
• Deep inside high‑rise cores or basements, both RSRP and SINR usually drop.
• 5G specifics
• Sub‑6 GHz 5G (most of Europe and many US deployments) behaves like 4G but usually offers more capacity.
• mmWave 5G (pockets of the Esim United States) is extremely fast outdoors, but a single wall or even your hand can drop RSRP and SINR to unusable.

How to see RSRP/RSRQ/SINR on your phone

Not every phone/carrier exposes every value. Try these:

iPhone (Field Test Mode)

1. Make sure mobile data is on and you have reception.
2. Dial 3001#12345# and press call. This opens Field Test Mode.
3. Look for menus labelled “LTE” or “NR-NSA/NR” (5G Non‑Standalone).
4. Find entries called RSRP, RSRQ, and SINR (sometimes “RS-SINR”).
5. If you can’t find them, back out and explore “All Metrics” or “Serving Cell Meas”. Availability varies by iOS version and network.

Pro tip: If you’re on 5G NSA, measurements may appear under LTE (for control) and under NR for 5G data. Check both.

Android (varies by brand)

• Pixel (and many stock Android phones): 1. Settings > About phone > SIM status. 2. Look for “Signal strength” (dBm). Some builds also show RSRP/RSRQ; others show RSSI/ASU only.
• Samsung: 1. Settings > About phone > Status information > SIM card status for signal strength. 2. Advanced readouts may be available via ServiceMode codes like *#0011# (not guaranteed; depends on carrier/region).
• If native menus don’t show RSRP/RSRQ/SINR, reputable network diagnostic apps can help. Install before you travel.

Accuracy tips: - Readings refresh as you move; give them 10–20 seconds after relocating. - Hold the phone naturally—don’t cover the top edge or antenna bands.

Make sense of the trio: common scenarios

• Strong RSRP, poor SINR/RSRQ
• You’re near a cell or indoors with strong reflections. Expect inconsistent speeds, buffering, or call drops in crowds.
• Try: move a few metres, face a window, or step outside. For stability, temporarily switch to LTE if 5G is flapping.
• Weak RSRP, decent SINR
• Rural edge or deep indoors. You may get steady but moderate speeds—fine for maps and messaging.
• Try: higher floor, near a window, or a different room. Low‑band cells travel further; your phone may prefer LTE in these spots.
• Good metrics but slow speeds
• Network congestion. Quality is fine; capacity is saturated (stadium, rush hour).
• Try: force a different band/tech (LTE vs 5G), reselect the cell (Airplane Mode toggle), or switch network via a local eSIM.

Traveller checklist: quick wins to improve your metrics

• Move three ways before anything else: 2–5 metres, nearer a window, or up/down one floor.
• Place your phone on a window ledge or table rather than in your pocket or bag.
• Toggle Airplane Mode for 10 seconds to reselect a potentially better cell.
• If 5G is unstable indoors, try LTE temporarily; if LTE is congested, try 5G where available.
• Turn on Wi‑Fi Calling for voice if data is OK but calls drop.
• Hotspot positioning: put the hotspot/phone by the best‑signal window; connect your laptop from inside.
• Consider a local or multi‑network eSIM so you can switch to whichever carrier gives better SINR/RSRQ in your area:
• Touring several countries? See Esim Western Europe.
• City‑hopping across the US and Canada? Check Esim North America and the country‑specific Esim United States.
• Planning Paris, Rome or Barcelona? Compare Esim France, Esim Italy and Esim Spain.
• Travelling as a team? Centralise connectivity choices with For Business.

Pro tips for faster, steadier data

• Prioritise SINR for throughput. A jump from 8 dB to 18 dB can boost real‑world speeds dramatically, even if RSRP hardly changes.
• Low bands (700/800/900 MHz) penetrate buildings best; mid bands (1800/2100/2600/3500 MHz) are faster but need clearer paths. Indoors, aim for the lowest‑band cell you can catch reliably.
• If your phone or hotspot supports it, enabling LTE/5G carrier aggregation and keeping battery above 20% can maintain higher‑order modulation under marginal SINR.
• Roaming doesn’t inherently worsen radio metrics; it’s about which network you’re on. Having multiple profiles lets you pick the cleanest signal locally via Destinations.
• Partners and travel providers: help your guests connect first time by sharing these thresholds and stocking multi‑region eSIMs via our Partner Hub.

FAQ

• What is a “good” RSRP for 5G?
• Aim for −80 to −90 dBm for consistently fast 5G. 5G can still work down to around −100 dBm, but speeds and stability depend heavily on SINR and band.
• Which metric matters most for speed: RSRP, RSRQ or SINR?
• SINR. It reflects how clean the signal is and determines the modulation your phone can use. RSRP provides the foundation; RSRQ hints at network loading and interference.
• Why do I have 4 bars but slow data?
• Bars often reflect signal strength (RSRP) but not quality (SINR/RSRQ) or cell congestion. Good strength plus poor quality or heavy load = slow.
• Is RSSI the same as RSRP?
• No. RSSI is a broader received power measurement including noise and interference. RSRP isolates the reference signal and is the standard metric for LTE/5G coverage assessments.
• Do buildings affect 4G and 5G differently?
• Yes. Both are attenuated by walls, but higher‑frequency 5G bands lose more signal indoors. mmWave 5G struggles through most materials; sub‑6 GHz 5G behaves more like 4G.
• Will switching to LTE help if 5G is flaky indoors?
• Often, yes. LTE on a lower band can deliver steadier SINR indoors, even if peak speeds are lower. Try LTE for calls and uploads; switch back to 5G outside for capacity.

The bottom line

Use RSRP to judge if you have enough raw signal, RSRQ to sense network cleanliness, and SINR to predict real speeds. Small moves (window, floor, angle) can add 5–20 dB where it matters. When a network’s quality is poor where you are, the fastest fix is often switching to a different carrier via an eSIM with regional coverage.

Next step: Compare country and regional options on Destinations.

A reliable mobile connection abroad depends on more than just signal bars. Three low‑visibility pieces of your phone’s setup do most of the heavy lifting: APN (Access Point Name), IMS (IP Multimedia Subsystem) registration, and Carrier Services (or carrier settings). Get these right and data, VoLTE calls, SMS/MMS and Wi‑Fi Calling tend to “just work”. Get them wrong, and you’ll see symptoms like “connected but no internet”, calls dropping to 3G (or failing entirely in 3G‑sunset countries), delayed messages or stubborn roaming issues. This guide translates the jargon, shows you exactly where to find the settings on iOS and Android, and explains when to reset versus edit—especially crucial if you’re travelling with an eSIM.

If you’re planning trips to the US, Europe or beyond, you’ll also find links to ready‑to‑use regional eSIM options such as Esim United States, Esim North America and Esim Western Europe. Keep this page handy for quick fixes on the road.

Quick definitions (plain English)

• APN (Access Point Name): The gateway settings your phone uses to reach the mobile data network. It includes the APN name, username/password if needed, and optional fields for MMS. Think of it as the Wi‑Fi password equivalent for mobile data.
• IMS (IP Multimedia Subsystem): The system carriers use to deliver modern voice and messaging over 4G/5G. If “IMS registration” is shown as “Registered”, your device can use VoLTE, SMS over IMS and Wi‑Fi Calling (subject to your carrier plan and device support).
• Carrier Services / Carrier Settings: On Android, “Carrier Services” is a Google app that provides up‑to‑date carrier configuration for things like RCS/IMS. On iPhone, “Carrier Settings” is a carrier bundle that tells iOS how to behave on a given network.

Pro tip: APNs get you on the internet; IMS keeps modern calls and texts working over 4G/5G; Carrier Services/Settings glue it all together.

What is APN IMS registration and why travellers should care

If you’ve searched “what is apn ims registration”, here’s the punchline: APN controls your data path; IMS registration confirms your phone is authorised to use IP‑based services like VoLTE and Wi‑Fi Calling. Travellers especially notice IMS after 3G shutdowns. In the United States, for example, carriers have retired 3G. Without IMS/VoLTE, voice calls may fail entirely or fall back to legacy tech that no longer exists. The right eSIM plus correct APN and a healthy IMS registration equals smooth sailing.

Where to find these settings: iOS and Android

iPhone (iOS)

• Check carrier settings version and update: 1. Settings > General > About. 2. If a “Carrier Settings Update” prompt appears, tap Update.
• View or edit APN (only if your carrier allows it):
• Settings > Mobile Data > Mobile Data Options > Mobile Data Network.
• If you don’t see “Mobile Data Network”, your carrier locks APN edits (normal for many profiles and eSIMs).
• Check VoLTE/Wi‑Fi Calling toggles:
• Settings > Mobile Data > Mobile Data Options > Voice & Data > ensure LTE/4G/5G is on and VoLTE enabled (label varies by iOS version).
• Settings > Phone > Wi‑Fi Calling > turn on if your plan supports it.
• Reset network settings (broad fix):
• Settings > General > Transfer or Reset iPhone > Reset > Reset Network Settings.

Pro tips: - On iOS, you often shouldn’t manually change APN; the carrier bundle sets it. If data breaks right after installing a new eSIM, remove and re‑add the eSIM before editing APN. - If roaming, enable Settings > Mobile Data > Data Roaming.

Android (varies by brand, similar paths)

• Update Carrier Services:
• Open Google Play Store > search “Carrier Services” > Update.
• Or Settings > Apps > Carrier Services > Storage & cache > Clear storage, then Update via Play Store.
• Check IMS registration status:
• Settings > About phone > SIM status (or Status) > IMS registration status = Registered is ideal.
• On some Samsung models: Settings > Connections > Mobile networks > Network operators and Voice networks; or service menu codes (advanced; use with caution).
• View/edit APN: 1. Settings > Network & internet (or Connections) > Mobile network > Access Point Names. 2. Select the eSIM/line if prompted. 3. Choose the correct APN or tap + to add one from your provider’s instructions.
• Reset APN to default:
• APN screen > three‑dot menu > Reset to default.
• Reset network settings:
• Settings > System > Reset options > Reset Wi‑Fi, mobile & Bluetooth.

Pro tips: - Keep “Preferred network type” on 4G/5G Auto. Turning off 4G/VoLTE can break calling in 3G‑sunset regions. - If you changed Private DNS, set it to Automatic while troubleshooting.

When to reset vs edit: a practical decision guide

Use this simple flow when something breaks after installing a SIM/eSIM or when roaming:

• Symptoms: “Connected without internet” or pages time out
• First: Toggle Airplane mode off/on; reboot phone.
• Then: Check data roaming is ON (when abroad).
• Next: Confirm the APN selected matches the profile provided by your eSIM provider.
• If APN fields look wrong/missing: Edit or add the APN per the provider’s exact instructions.
• Still failing: Reset APN to default (Android) or remove/re‑add eSIM (iOS/Android).
• Last resort: Reset Network Settings.
• Symptoms: Calls failing, or no VoLTE/Wi‑Fi Calling
• Check IMS registration (Android) and VoLTE/Wi‑Fi Calling toggles.
• Update Carrier Services (Android) or Carrier Settings (iOS).
• If you’re in the US, ensure your device model is VoLTE‑compatible with local networks. Consider a data‑only plan and calling apps if not. See Esim United States.
• Symptoms: SMS/MMS delayed or failing
• Ensure mobile data is enabled (MMS often needs data).
• Verify APN “MMS” fields are present if your provider requires them.
• Update Carrier Services; clear its storage and re‑open Messages (Android).

Golden rules: - Edit APN only if you have exact values from a trusted source (your carrier or eSIM provider). - Prefer “Reset APN to default” over random tweaks. - Avoid third‑party APN profiles from unverified websites.

How APN and IMS affect VoLTE, Wi‑Fi Calling and roaming

• VoLTE (Voice over LTE): Requires IMS registration and carrier/device support. Without IMS in 3G‑sunset regions (e.g., the US), calls may not connect at all. For trips that include the US or Canada, see Esim North America.
• Wi‑Fi Calling: Also rides on IMS. Helpful indoors or in rural areas. Must be enabled on your device and provisioned by the carrier.
• SMS over IMS: Modern networks route texts over LTE/5G via IMS. If IMS registration flips to “Not Registered”, texts may delay or revert to older paths, sometimes failing on data‑only profiles.
• MMS: Often relies on correct APN “MMS” fields and mobile data. Some eSIM data plans do not support MMS on the data line; use chat apps if needed.
• Roaming: The APN set by your eSIM should generally work across partner networks. If you switch networks manually, keep APN unchanged unless told otherwise.

Traveller tip: - For European trips that hop across borders without fuss, regional plans like Esim Western Europe are designed to “auto‑roam” with the right APN pre‑loaded. Country‑specific options include Esim France, Esim Spain and Esim Italy.

Troubleshooting checklist (save for the road)

1. Confirm your plan is active and has data balance.
2. Ensure the correct line/eSIM is set for Mobile Data and Calls (dual‑SIM phones).
3. Turn Data Roaming on when abroad.
4. Preferred network mode: 4G/5G Auto.
5. APN: Select the profile provided by your carrier/eSIM. If missing, add it exactly as given.
6. Toggle Airplane mode off/on; then reboot.
7. Update Carrier Services (Android) or accept Carrier Settings Update (iOS).
8. Check IMS registration status (Android). If “Not registered”, ensure VoLTE is enabled and try a different local network if allowed.
9. Clear Carrier Services storage (Android) and reopen your messaging app if RCS/SMS is flaky.
10. Remove and re‑add the eSIM profile if issues began right after installation.
11. Reset APN to default (Android), then re‑select the correct APN.
12. Reset Network Settings as a last resort.

Pro tip: - Keep a screenshot of working APN fields before experimenting. It makes recovery painless.

Planning connectivity by destination

Pick an eSIM that already includes correct APN and roaming parameters to minimise manual fixes: - Browse country and regional options on Destinations. - North America trips: Esim North America or the US‑specific Esim United States. - Western Europe touring: Esim Western Europe or country‑specific choices such as Esim France, Esim Spain and Esim Italy.

For teams on the move, centralise setup guidance and support via For Business. If you’re a reseller or travel partner, see our Partner Hub for resources and onboarding.

FAQs

• What does “IMS registration: Not registered” mean?
• Your device isn’t currently authorised for IP‑based services like VoLTE/SMS over LTE on that SIM/network. Update Carrier Services (Android), ensure VoLTE is on, reboot, and try another partner network if available. Some data‑only plans won’t register IMS for voice features.
• Will changing my APN affect VoLTE?
• Indirectly. A wrong APN can block data paths needed for IMS/RCS features. Use only the APN provided by your carrier/eSIM. Avoid editing the “APN type” to include “ims”; that entry is typically system‑managed.
• Where do I find APN on iPhone? I can’t see the fields.
• Many carriers lock APN editing on iOS. If Settings > Mobile Data > Mobile Data Options > Mobile Data Network isn’t visible, the carrier bundle manages it automatically. Remove/re‑add your eSIM or accept a Carrier Settings Update instead of editing.
• Should I reset network settings or just APN?
• Start with APN reset (Android) or re‑adding the eSIM. Only use full Network Settings reset if simpler steps fail—it will forget saved Wi‑Fi and Bluetooth pairings.
• Do I need Carrier Services on Android?
• Yes. It’s a Google component that updates carrier config for IMS/RCS. Keep it updated. If messages misbehave, clear its storage and relaunch your messages app.
• Why do calls fail in the US but data works?
• Likely a VoLTE/IMS issue on a 3G‑sunset network. Ensure VoLTE is on, IMS is registered, and your device is compatible. If not, use data‑based calling apps and pick a plan optimised for the region, such as Esim United States.

The bottom line

• APN gets you online; IMS keeps VoLTE/SMS/Wi‑Fi Calling alive; Carrier Services/Settings keep both in sync.
• On iOS, avoid manual APN edits unless instructed. On Android, use “Reset to default” before entering trusted APN values.
• For travel, choose eSIMs with correct roaming profiles and keep VoLTE enabled—critical in 3G‑sunset countries.

Next step: pick a region‑ready eSIM on Destinations and travel with confidence.

Travelling with an eSIM and need to get your laptop or tablet online? Turning your phone into a hotspot (or tethering via USB/Bluetooth) is often the most reliable way to work, stream, or map your way through a new city. This guide explains how to set up and optimise hotspot and tethering on eSIM devices, what limits to expect, how to tweak APN settings when hotspot is blocked, and how to keep things secure and cool under load. You’ll also find device-limit guidance, speed expectations, practical VPN advice for laptops, and battery/heat tips drawn from real-world use. Where rules and networks vary by country, we point to the right country pages and Playbooks so you can check local notes before you land. If you just need the bottom line: yes, hotspot works on most eSIMs, but plan rules, device caps, and APN settings often decide how well it works.

• Planning a trip? Start at Destinations to check local tips.
• Regional picks: Esim North America, Esim Western Europe, Esim United States, Esim France, Esim Italy, Esim Spain.

Hotspot vs tethering: the quick definitions

• Personal hotspot: Your phone creates a Wi‑Fi network others can join.
• USB tethering: Your phone shares data over a cable to one computer; fastest and lowest latency; charges at the same time.
• Bluetooth tethering: Low-power, slow; fine for basic chat/email.
• Tethering vs hotspot: Tethering is the umbrella term; hotspot is usually Wi‑Fi sharing.

eSIM doesn’t change the mechanics: if your plan allows it, hotspot/tethering will behave like a physical SIM. The differences come from plan permissions, APN profiles, local carrier policies and device limits.

Does your eSIM plan allow hotspot/tethering?

Most travel eSIMs allow hotspot, but not all. Some carriers disable tethering on certain APN profiles or cap the number of devices.

Checklist before you rely on it: 1. Check the plan description for “tethering allowed” or “hotspot support”. 2. Look for data policy notes on the country/region page (start at Destinations or specific regions like Esim North America or Esim Western Europe). 3. Expect fair use in Europe and some throttling at peak times. If your plan says “mobile use only”, hotspot may be blocked. 4. Corporate travellers: consider a pooled or team plan so you’re not sharing a single phone. See For Business.

Tip: If hotspot is off or greyed out as soon as you enable it, it’s often an APN configuration issue. See the APN section below.

Set up hotspot on your phone (and fix common snags)

iPhone/iPad (iOS/iPadOS)

Basic setup: 1. Settings > Mobile Data > toggle Mobile Data on. 2. Tap Personal Hotspot. 3. Turn on Allow Others to Join. 4. Set a strong Wi‑Fi password (12+ characters). Avoid birthdays or simple words. 5. Optional: toggle Maximise Compatibility to use 2.4 GHz (better range, lower speed).

If Personal Hotspot is missing or won’t enable, check APN fields: - Go to Settings > Mobile Data > Mobile Data Network. - You may see three APN sections: Mobile Data, LTE Setup (optional), and Personal Hotspot. - Copy the APN value from Mobile Data into Personal Hotspot (username/password too, if present). - Return to Personal Hotspot and try again.

Pro tips (iOS): - If devices struggle to join, enable Maximise Compatibility to force 2.4 GHz, then try 5 GHz again later for higher speeds. - USB tether for long work sessions: plug into your laptop and enable Personal Hotspot; macOS/Windows will auto-detect. - Family Sharing can auto-join trusted Apple devices without sharing the password.

Android (steps vary by brand, but generally)

Basic setup: 1. Settings > Network & Internet (or Connections) > Hotspot & tethering. 2. Tap Wi‑Fi hotspot (or Mobile Hotspot). 3. Set Network name (SSID), Security = WPA2 or WPA3, and a strong password. 4. Toggle hotspot On. 5. Optional: Set AP band to 5 GHz for speed if all your devices support it.

If hotspot toggles off instantly or says “Not available”: - Check Data Saver/VPN apps aren’t blocking tethering. - APN profile may be missing the DUN flag (tethering APN). Try: - Settings > Mobile network > Access Point Names. - Create a new APN using the APN details provided with your eSIM. - Under APN type, include: default,supl,dun - Save, select the new APN, toggle flight mode Off/On, then retry hotspot.

Note: Some carriers lock APN editing. If you can’t add “dun”, use USB tether (often unblocked) or contact support via your plan page on Destinations.

USB and Bluetooth tethering

• USB (iOS/Android): Plug your phone into your computer; enable Personal Hotspot/USB tethering. Best for speed, latency, and power (it charges your phone).
• Bluetooth: Pair devices; enable Bluetooth tethering. Useful when Wi‑Fi is congested, but speeds are modest.

Device limits and realistic speeds

Device caps: - iPhone: typically up to 5 Wi‑Fi clients (plus 1 via USB and 1 via Bluetooth in some cases). Behaviour varies by iOS and device. - Android: commonly up to 10 Wi‑Fi clients, configurable in Hotspot settings. Some models/carriers cap lower.

Performance expectations: - The hotspot speed ceiling is your phone’s own mobile data speed. Expect 5–15% overhead for Wi‑Fi sharing. - 5 GHz hotspot usually outperforms 2.4 GHz (less interference), but range is shorter. - USB tether bypasses Wi‑Fi overhead and interference, improving stability and latency—ideal for calls and remote desktop.

Pro tips for better throughput: - Place the phone near a window for stronger mobile signal; avoid pockets and bags. - If 5G is weak or causing drops, try 4G/LTE only mode for steadier performance. - Change the hotspot channel (Android) if nearby Wi‑Fi networks are clashing. - Avoid chaining multiple VPNs (phone + laptop). See the VPN section.

Using VPN on a laptop over hotspot

A VPN can protect traffic on public networks, but it introduces overhead.

What works best while travelling: - Prefer modern protocols (WireGuard, IKEv2) over older, heavy options (OpenVPN TCP). Try UDP-based connections for lower latency. - If your corporate VPN is mandatory, enable split tunnelling so only work apps use the VPN; streaming and updates go direct. - Use a kill switch to prevent data leakage if mobile signal drops. - Banking/gambling sites may flag unusual IP geolocation across borders. Temporarily disable the VPN if legitimate services won’t load. - Test your “work stack” (VPN + conferencing + RDP/VDI) on hotspot before you travel.

If speeds collapse when starting the VPN: - Try a nearer VPN location. - Switch protocol (WireGuard/IKEv2). - Use USB tether to reduce latency and packet loss.

Business teams that need guaranteed performance should consider device-per-person rather than sharing a single hotspot. See For Business for options, and the Playbooks linked from Destinations for country-specific notes.

Battery, heat and reliability on the road

Hotspot is power-hungry. Add 5G radios, and heat becomes the bottleneck.

Practical checklist: - Use USB tether when possible: fastest and charges simultaneously. - If on Wi‑Fi hotspot, keep the phone on a table/stand with airflow; avoid dashboards and direct sun. - Disable unused radios: turn off Bluetooth/NFC if you don’t need them. - Lock the phone to 4G/LTE in weak 5G areas to reduce hunting and heat. - Lower screen brightness; use Low Power Mode (iOS) or Battery Saver (Android). - Keep a power bank handy, or a 20W+ charger for fast top-ups.

If the phone overheats: - Pause heavy downloads/updates on connected devices. - Switch to 2.4 GHz (Maximise Compatibility) to reduce RF load. - Move to cooler shade; remove thick cases temporarily.

Safe sharing: security and access control

Do: - Use WPA2 or WPA3 with a strong, unique password. - Change the hotspot password after sharing with new people. - Enable automatic turn-off when no devices are connected (Android setting on many models). - On iOS, consider Family Sharing for known Apple devices.

Avoid: - Open (password-free) hotspots. - Sharing with strangers or in crowded venues where shoulder-surfing is easy. - Leaving hotspot on when you walk away from your laptop.

Extra layer: - Keep your phone and laptop fully patched. - On Windows/macOS, mark the hotspot as “Private/Trusted” only if it’s yours; otherwise keep it “Public” to tighten the firewall.

Troubleshooting: common tethering blockers and fixes

Symptom: Hotspot setting is greyed out or turns off immediately - Cause: Plan blocks tethering or APN lacks DUN. - Fix: Edit APN (Android) to include APN type default,supl,dun, or copy APN into the iOS Personal Hotspot APN field. If APN editing is locked, try USB tether, then contact support via your plan page under Destinations.

Symptom: Devices connect to hotspot but no internet - Cause: Captive portal or exhausted data. - Fix: Open a browser on the phone itself to trigger any network sign-in. Check your remaining data in the app/portal.

Symptom: Poor speed on hotspot but good on phone - Cause: Wi‑Fi interference or 2.4 GHz congestion. - Fix: Switch hotspot band to 5 GHz (Android) or disable Maximise Compatibility (iOS).

Symptom: VPN disconnects frequently - Cause: High packet loss over Wi‑Fi or marginal 5G signal. - Fix: Use USB tether; lock to LTE; change VPN protocol to WireGuard/IKEv2.

Symptom: Laptop won’t see the hotspot - Cause: Hidden SSID or band mismatch. - Fix: Ensure SSID is broadcast; try the other band; forget and re-add the network on the laptop.

Country notes and planning

Rules and performance vary by market and carrier. Before you fly: - United States: 5G coverage is broad but varies by city and band. Check Esim United States for plan notes and any hotspot caveats. - Western Europe: Generally friendly to tethering on mainstream plans; watch fair-use policies. Start with Esim Western Europe. - France/Italy/Spain: Review local network compatibility and APN notes in Esim France, Esim Italy and Esim Spain. - Regional coverage maps and Playbooks are linked from Destinations.

Partners and travel teams can access implementation guidance and updates via the Partner Hub.

Pro tips from the road

• Prioritise USB tether for calls, RDP and VPN-heavy work.
• Keep a short, quality USB‑C or Lightning cable in your bag; cheap cables cause flaky tethering.
• Set laptop updates to “metered connection” to avoid background downloads chewing your data.
• Share with fewer devices. Each extra device adds overhead and contention.
• If you must share widely (family/team), consider a dedicated travel router that connects to your phone’s hotspot and manages the rest—then place the phone somewhere with the best signal.

FAQ

Q: Do all eSIM plans allow hotspot/tethering? A: No. Most travel plans do, but some block it. Check your plan details on Destinations or the regional page (e.g. Esim North America, Esim Western Europe).

Q: How many devices can I connect to my phone’s hotspot? A: iPhone typically supports around 5 Wi‑Fi devices; Android often allows up to 10 (varies by model and carrier). More devices mean less bandwidth per user.

Q: Will using a VPN on my laptop slow things down? A: A bit. Expect additional latency and some throughput loss. Use USB tether, a modern protocol (WireGuard/IKEv2), and split tunnelling to keep speeds usable.

Q: My hotspot toggle is greyed out on eSIM. What can I do? A: Ensure your plan allows tethering. Then check APN: on iOS, copy the data APN into the Personal Hotspot APN field; on Android, include “dun” in APN type (default,supl,dun). If APN editing is locked, try USB tether or contact support via your plan page.

Q: Is 5G always better for hotspot? A: Not always. Weak 5G can fluctuate and overheat your phone. Locking to LTE can deliver steadier performance for calls and uploads, especially indoors.

Q: What’s the safest way to share with a friend? A: Use WPA2/3 with a strong password, share via QR code, and change the password afterwards. Turn the hotspot off when done.

Next step: Choose your destination, confirm hotspot support on the plan page, and note any APN specifics in the Playbooks. Start at Destinations.

Travellers love the promise of “unlimited data”, but networks define “unlimited” differently from how most of us use the word. In practice, unlimited plans almost always come with a Fair‑Use Policy (FUP) and speed management rules. Understanding these is the difference between smooth streaming in a hotel lobby and a surprise crawl when you really need maps, ride‑hailing, or boarding passes.

This guide explains unlimited data throttling fair use in plain English. You’ll learn how throttling differs from deprioritisation, the typical caps you’ll see at home and while roaming, how to spot what’s happening on your line, and practical ways to avoid slowdowns on the road. We’ll also flag common gotchas—like hotspot limits and video shaping—that often hide in the small print. Planning a trip? We’ll show you how to pick a plan or travel eSIM with the right fair‑use terms for your usage, whether you’re heading to the US, Spain, Italy or across Western Europe.

What “Unlimited” Really Means Today

“Unlimited” almost never equals “full speed, all the time, for everything.” Most unlimited plans give you:

• A bucket of high‑priority or full‑speed data (often called premium data)
• A separate, often smaller allowance for hotspot/tethering
• A Fair‑Use Policy that applies especially when roaming

Once you hit a threshold—monthly, weekly, or even daily—your speeds may be managed in two distinct ways:

• Throttling: your line is capped to a fixed, low speed (for example 128 kbps, 512 kbps, or 1–3 Mbps)
• Deprioritisation: your line stays “unlimited”, but drops in priority behind others when cells are busy

Carriers use both to keep networks stable. For travellers, the impact varies enormously by location and time of day. Understanding unlimited data throttling fair use before you buy prevents surprises once you land.

Fair‑Use Policies (FUP) in practice

FUPs are there to stop unusual consumption that affects other users. Typical patterns we see:

• Domestic unlimited: 30–100 GB of “premium” data before deprioritisation may kick in
• Roaming FUP: 5–30 GB at full speed in a foreign country, then slower speeds or deprioritisation
• Daily high‑speed passes: 1–5 GB per day, then 1–3 Mbps until midnight
• Hotspot allowances: 5–50 GB at full speed; after that, tethering may be banned or throttled

These are ranges, not promises—always check the plan page. For region‑specific options, browse Destinations or see Esim United States, Esim Spain, Esim France, Esim Italy, Esim Western Europe and Esim North America.

Hotspot and video shaping

Two limits people often miss:

• Hotspot/tethering: Many “unlimited” plans only include a fixed hotspot allowance. After that, tethering may be slowed or blocked.
• Video streaming: Some plans cap video at SD (480p) or HD (720p) using traffic shaping, regardless of your available bandwidth.

If you rely on hotspot for work or need HD/4K video, choose a plan that explicitly includes it.

Throttling vs Deprioritisation: Know the Difference

These terms are not interchangeable. Here’s how to recognise each and why it matters.

• Throttling (speed cap)
• What it is: A hard limit on your maximum speed once you hit a threshold.
• When it triggers: After using your premium allowance, or after hotspot/video caps, or during traffic shaping rules.
• How it feels: Consistently slow across locations and times—e.g., streams drop to SD, large downloads crawl, video calls struggle.
• Typical numbers: 128–512 kbps for heavy throttles; 1–3 Mbps for lighter management.
• Deprioritisation (queue position)
• What it is: Your traffic moves lower in the queue only when the network is congested.
• When it triggers: After a premium data threshold, or at busy cells (stadiums, stations, city centres at peak).
• How it feels: Variable. Slow at busy times/places; normal or fast at quieter cells or off‑peak hours.
• Typical signs: Speed tests vary widely by time and location; uploads may feel especially sluggish in crowds.

Why it matters: If you’re throttled, changing time or place won’t help much. If you’re deprioritised, moving one block, switching to a less loaded band/technology (e.g., 4G to 5G or vice versa), or waiting until off‑peak can restore high speeds.

Typical caps for travellers, by region

These are indicative ranges to help set expectations. Always review plan specifics on the product page.

• United States / North America
• Premium data on “unlimited”: commonly 30–100 GB before deprioritisation
• Hotspot: 5–50 GB at full speed; then slower or disabled
• Post‑FUP throttle: 128–512 kbps on some budget plans; others keep full speed but deprioritise
• See Esim United States and Esim North America for travel‑friendly options.
• Western Europe (EU/UK)
• Domestic unlimited often very generous; EU‑roam FUPs of 5–35 GB are common
• Daily unlimited passes: 1–5 GB/day at full speed then 1–3 Mbps
• Hotspot limits vary; check if tethering is included in the FUP
• See Esim Western Europe, plus country pages like Esim France, Esim Italy and Esim Spain.
• Multi‑country trips
• Regional eSIMs bundle fair‑use per country or per plan. Expect FUPs in the 5–30 GB range for short trips.
• If you’re a power user, consider stacking plans or selecting tiers with higher premium data.

How to spot slowdowns (and prove what’s happening)

Use this quick, repeatable process:

1. Check your usage in the app/portal - Look for “premium data used”, “hotspot used”, or “FUP reached” messages.
2. Run two speed tests - One at a busy time (e.g., 6–8 pm), one off‑peak (early morning). Note ping, download, and upload. - Deprioritisation usually shows big time‑of‑day swings; throttling stays consistently capped.
3. Toggle network modes - Switch 5G to 4G (LTE), or vice versa. Sometimes a less crowded 4G band beats congested 5G.
4. Move 100–300 metres - Try a different street corner or side of the building. Cell boundaries and load change quickly.
5. Test with and without VPN - A VPN won’t fix volume‑based throttles, but it can neutralise app‑specific shaping. Compare results.
6. Try another device or SIM/eSIM if available - If the second line flies, your original line is likely managed; if both are slow, it’s probably coverage or congestion.

Pro tips: - Record screenshots of usage counters and speed tests. It’s useful if you escalate with support. - If tethering is slow but on‑device usage is fine, you’ve likely hit a hotspot cap.

How to avoid or minimise slowdowns

Follow these steps before and during your trip:

1. Choose the right plan tier - Prefer plans that advertise “premium data” amounts and explicit hotspot allowances. - For multi‑country trips with heavy usage, consider regional plans like Esim Western Europe or Esim North America with generous FUPs.
2. Match the plan to your destination - In the US, capacity varies by city and carrier. Travel‑specific options on Esim United States are tuned for visitors. - In Europe, check country pages—Esim France, Esim Italy, Esim Spain—for local FUP details.
3. Keep hotspot usage intentional - Download large files over hotel Wi‑Fi. - If you must tether, reduce video quality and pause cloud backups.
4. Optimise your apps - Turn off auto‑updates and background sync while on mobile data. - Pre‑download offline maps and playlists before you fly. - Set streaming apps to 480p/720p on mobile; switch back to higher quality on Wi‑Fi.
5. Manage your radios - If 5G is patchy, force 4G/LTE to avoid sticky, congested NSA 5G cells. - If upload is critical (video calls), test at different times or locations to dodge deprioritised uplink.
6. Carry a fallback - Add a second eSIM from a different network in your dual‑SIM phone. When one is congested, switch. - For teams, pooled or centrally managed data on For Business helps ensure reliable capacity.
7. Read the small print - Look for words like “after X GB, speeds reduced to 1 Mbps,” “video streams at SD,” or “hotspot 10 GB”.

Pro tips: - City centres at lunchtime and early evenings are peak hours. Plan uploads and large downloads for mornings. - Rural areas may have excellent peak speeds but fewer carriers. Keep a secondary eSIM for redundancy.

Heavy‑use and business travellers

If you’re syncing large files, running live demos, or supporting a team:

• Pick plans with stated premium data allowances and business‑grade hotspot limits.
• Use dual connectivity: one line for primary data, another as a hot backup.
• Consider centrally managed solutions via For Business for pooled data and support. Channel or travel partners can explore the Partner Hub.

Checklist: Before you buy an “unlimited” plan

• Is there a premium data allowance before deprioritisation? How many GB?
• What is the throttle speed after the FUP is reached?
• How much hotspot/tethering is included at full speed? What happens after?
• Is video streamed at a fixed resolution on mobile data?
• Are the FUP and hotspot limits different when roaming?
• Can I view real‑time usage counters in an app or portal?
• What networks and bands are supported at my destination?
• Does the plan suit my itinerary? Check regional options on Destinations.

FAQ

Q: What’s the difference between throttling and deprioritisation? A: Throttling is a fixed speed cap imposed after you hit a limit (e.g., 512 kbps). Deprioritisation only lowers your queue position during congestion; speeds can still be fast at quieter times or places.

Q: How many gigabytes can I use before I’m slowed on “unlimited” plans? A: It varies by plan and region. Common thresholds are 30–100 GB of premium data domestically, and 5–30 GB when roaming on travel eSIMs. Some plans throttle after that; others simply deprioritise.

Q: Does a VPN bypass throttling or deprioritisation? A: No for volume‑based throttling and deprioritisation—they apply regardless of encryption. A VPN may help only if the network is shaping specific apps (e.g., video), not if you’ve hit a usage cap.

Q: Why is my data slow even before I hit a cap? A: Likely congestion, weak signal, or sub‑optimal bands. Try another location, switch between 5G and 4G, and test at off‑peak times. Compare results to distinguish network load from policy limits.

Q: Is hotspot included in unlimited plans? A: Often in limited amounts (e.g., 5–50 GB). After the hotspot allowance, tethering may be throttled or blocked. Always check the hotspot line item separately from general data.

Q: Will 5G keep me safe from slowdowns? A: 5G can deliver higher peak speeds, but policy still applies. You can still be deprioritised on a busy 5G cell or throttled after hitting a FUP threshold.

Next step: Plan your trip with the right fair‑use and speed terms by browsing regional options on Destinations.

If you travel with an eSIM, two features determine whether your calls “just work”: VoLTE (Voice over LTE) and Wi‑Fi Calling (VoWiFi). Both let you place normal voice calls without falling back to old 3G/2G networks. That matters because many countries have retired 3G and some are winding down 2G; in the United States, for example, VoLTE is essential for voice. This guide explains how to set up and troubleshoot VoLTE and Wi‑Fi Calling abroad, especially when you’re using a data‑only travel eSIM and want your home number reachable. We’ll cover carrier prerequisites, dual‑SIM line selection, roaming toggles, and practical fixes for the common pitfalls travellers hit. If you only skim one section, make it the “Set‑up recipes” and the troubleshooting tree. For destination specifics and compatible plans, browse our regional eSIMs, including Esim United States, Esim Western Europe and Esim North America, or explore all Destinations.

What VoLTE and Wi‑Fi Calling mean when you roam

• VoLTE: Your phone makes standard cellular calls over 4G/LTE (or 5G) networks using IMS. It’s required in markets where 3G is shut down (e.g., USA). Without VoLTE support on the visited network, calls may fail or drop.
• Wi‑Fi Calling (VoWiFi): Your carrier routes your normal phone number over any Wi‑Fi or mobile data connection. Abroad, this lets your home number ring even if you’ve disabled roaming on your home SIM. Think of it as “your number, over the internet”.

How this plays with eSIM: - Most travel eSIMs are data‑only. You keep your home SIM for your number and use Wi‑Fi Calling over your eSIM’s data. - If you buy a local eSIM with voice, you’ll use VoLTE for direct cellular calling in country. Ensure that plan and your device are VoLTE‑enabled on the visited network.

Pro tip: For the US, prioritise VoLTE‑capable devices and plans; see Esim United States. For multi‑country trips, check regional coverage like Esim Western Europe and Esim North America.

Prerequisites: what must be true for calls to work

Before boarding, confirm the essentials based on how you’ll call.

If you’ll keep your home number via Wi‑Fi Calling over a travel eSIM (most common)

• Your phone supports Wi‑Fi Calling and it’s enabled on your home carrier account.
• Your home carrier allows Wi‑Fi Calling while abroad. Many do; some restrict it by country or plan.
• You can receive an SMS while on Wi‑Fi (needed for banking/2FA). Some carriers only deliver SMS over cellular; check before you rely on it.
• Your travel eSIM provides a stable data connection (4G or better).
• You know how to set “Default Voice Line” (iPhone) or “Preferred SIM for Calls” (Android) to your home SIM.

If you’ll use a local eSIM for voice via VoLTE

• The eSIM plan includes voice service (many travel eSIMs are data‑only).
• Your phone supports VoLTE on the visited carrier’s bands.
• The eSIM/carrier has provisioned IMS/VoLTE on your line.
• You’ve enabled VoLTE in device settings and allowed voice roaming.
• For the US: No 3G fallback; without VoLTE your calls won’t work.

Planning resources: - Country pages highlight network specifics and plan types: Destinations - Popular country packs with excellent LTE coverage: Esim France, Esim Italy, Esim Spain

Set‑up recipes that just work

Recipe A: Keep your home number alive with Wi‑Fi Calling over a data eSIM

This gives you cheap local data and your usual number for incoming/outgoing calls and SMS.

iPhone (iOS 16/17): 1. Install and activate your travel eSIM. Confirm data works. 2. Settings > Mobile Data: - Mobile Data: select your Travel eSIM. - Turn on Data Roaming for the Travel eSIM. - For your Home SIM: keep Data Roaming OFF to avoid charges. 3. Tap Default Voice Line: set it to your Home SIM. 4. Wi‑Fi Calling: Settings > Phone > Wi‑Fi Calling > On (for Home SIM). If your carrier presents a terms screen, accept/verify. 5. Allow Mobile Data Switching: - Recommended: ON. iPhone will use data from your Travel eSIM to support calls on your Home SIM, without using home data roaming. - Safety check: keep “Data Roaming” on the Home SIM OFF, so switching cannot trigger paid roaming. 6. Make a test call with Wi‑Fi or strong 4G data. You should see “Wi‑Fi” or “Wi‑Fi Calling” in the status.

Android (Pixel/Samsung/OnePlus – wording varies): 1. Install and activate your travel eSIM. Confirm data works. 2. Settings > Network & Internet > SIMs: - Mobile Data: Travel eSIM. - Data Roaming: ON for Travel eSIM; OFF for Home SIM. - Preferred SIM for Calls: Home SIM. 3. Wi‑Fi Calling: Settings > Wi‑Fi Calling > On for Home SIM. - Calling preference: Prefer Wi‑Fi (or Wi‑Fi preferred) if available. 4. Optional: “Use SIM data for calls on other SIM” or “Dual SIM data switching” ON, if available. It will use Travel eSIM data to sustain Home SIM calls. 5. Test an inbound and outbound call.

Pro tips: - Keep the Phone app’s line selector visible before dialling so you don’t accidentally place a call on the travel eSIM. - If SMS over Wi‑Fi isn’t supported by your home carrier, briefly enable home SIM cellular (still with data roaming OFF) to receive 2FA codes.

Recipe B: Use a local eSIM for native voice via VoLTE

Use this if your eSIM includes minutes or you need a local number.

All devices: 1. Confirm the eSIM plan includes voice. 2. Settings > Mobile/Cellular > enable VoLTE/4G Calling for that line. 3. Enable Voice Roaming if you plan to cross borders within the plan’s region (e.g., EU). 4. Network mode: 4G/5G Auto. Avoid 3G/2G‑only modes. 5. Place a test call. Check the status bar shows 4G/VoLTE during the call (not “3G/ H/ E”).

If calls drop to 3G or fail: - Update carrier settings (iPhone prompt) or install the APN/IMS config provided. - Reboot; re‑insert eSIM if needed. - Manually select a different partner network in the same country.

Country specifics and planning

• United States: 3G is shut down; VoLTE is mandatory for cellular calling. If your phone or plan doesn’t do VoLTE on the visited network, use Recipe A (Wi‑Fi Calling over data) as your fallback. See Esim United States.
• Canada, Mexico and USA trips: plan for cross‑border behaviour and partner networks. Check Esim North America.
• Western Europe: Broad VoLTE support and EU‑wide roaming on many plans. Recipe A works well for keeping your home number; Recipe B is easy if your eSIM includes voice. See Esim Western Europe.
• Popular single‑country picks with strong LTE: Esim France, Esim Italy, Esim Spain.

Travelling as a team? Centralise setup guidance and plan choice via For Business or coordinate with your reseller through our Partner Hub.

Troubleshooting tree: call fails or drops when abroad

Start with your scenario and follow the checks in order.

1) My home number doesn’t ring; I’m using a data eSIM - Is Wi‑Fi Calling enabled on the home SIM? Turn it on. - Can your device reach data? Open a web page; if not, fix data/APN first. - Carrier allows Wi‑Fi Calling abroad? If unsure, test on hotel Wi‑Fi; if it only works on your home ISP, your carrier may restrict it. - iPhone: Allow Mobile Data Switching ON; Home SIM Data Roaming OFF. - Android: Wi‑Fi Calling preference = Prefer Wi‑Fi; Dual SIM data switching ON (if available). - Still no joy: toggle Airplane Mode ON then enable Wi‑Fi only; try calling. If it now works, your carrier might prioritise Wi‑Fi Calling when cellular is off.

2) Calls fail in the USA on a local SIM/eSIM - Confirm the line supports VoLTE on that network. - Device: VoLTE/4G Calling ON; network mode 4G/5G. - If calls drop to 3G or never connect, switch to a different partner network or use Recipe A as a fallback.

3) I can call but SMS 2FA won’t arrive - Some carriers don’t deliver SMS over Wi‑Fi. Temporarily allow the home line to register on cellular (keep Data Roaming OFF) to receive codes. - Ask your bank to enable app‑based or email 2FA as a travel workaround.

4) Calls use the wrong line - Set Default Voice Line (iPhone) or Preferred SIM for Calls (Android) to the correct SIM. - Before dialling, check the SIM selector in the Phone app; on iPhone, long‑press the call button to switch lines.

5) Wi‑Fi Calling toggles are missing - Your carrier or device may not support it, or it’s not provisioned. Update carrier settings/OS, or contact your carrier to enable. - Some countries restrict VoIP/Wi‑Fi Calling; try a different network/Wi‑Fi.

6) Audio is poor or calls drop on Wi‑Fi - Switch Wi‑Fi to 5 GHz, or move closer to the router. - Turn off VPN; some VPNs break IMS traffic. - Disable battery/data savers that restrict background data.

Pro tips and gotchas

• Prefer Wi‑Fi Calling for long international calls. It uses your home plan’s domestic rates for many carriers, but always check your tariff.
• Avoid bill shock: keep Data Roaming OFF on your home SIM. You can still use Wi‑Fi Calling via the travel eSIM’s data if mobile data switching is enabled.
• In dual‑SIM mode, iPhone can show “Primary” and “Secondary”; rename them to “Home” and “Travel” so you don’t mis‑dial.
• Emergency calls: Wi‑Fi Calling may not route accurately abroad. Know the local emergency number and, where possible, place emergency calls over the local cellular network.
• US travellers: bring a VoLTE‑ready device. Older handsets that relied on 3G voice won’t work for calling.
• Business itineraries: standardise a setup playbook (Recipe A) for your team and test before departure. See For Business.

FAQs

Q: What’s the simplest way to keep my number when I use a travel eSIM? A: Use Wi‑Fi Calling on your home SIM over your travel eSIM’s data (Recipe A). Set your travel eSIM as the data line, keep data roaming off on the home SIM, and enable Wi‑Fi Calling.

Q: Do all travel eSIMs support voice calls with VoLTE? A: Many travel eSIMs are data‑only. If you need native voice, choose an eSIM that explicitly includes minutes/voice and make sure VoLTE is supported in your destination.

Q: Will Wi‑Fi Calling work in every country? A: Not always. Most carriers support it internationally, but some restrict usage by location or plan. A few countries and networks limit VoIP/Wi‑Fi Calling. Test on both Wi‑Fi and mobile data at your destination.

Q: My SMS codes aren’t arriving while abroad. Why? A: Some carriers don’t deliver SMS over Wi‑Fi Calling. Temporarily register your home SIM on cellular (with data roaming off) to receive them, or switch to app‑based 2FA.

Q: In the USA, my calls fail on a local SIM. What now? A: You likely need VoLTE on that network. Enable VoLTE/4G Calling, set network mode to 4G/5G, and try another partner network. If still failing, use Wi‑Fi Calling over your travel eSIM’s data as a fallback. See Esim United States.

Q: How do I avoid using the wrong SIM for calls or data? A: Set your Default Voice Line/Preferred SIM for Calls to your chosen number, and your Mobile Data line to the travel eSIM. On iPhone, consider turning on “Allow Mobile Data Switching” with data roaming off on your home SIM to stay safe.

The quick checklists

Before you fly: - Update iOS/Android and carrier settings. - Confirm Wi‑Fi Calling is enabled on your home SIM and supported abroad. - Decide your calling method: Wi‑Fi Calling over data (Recipe A) or local voice via VoLTE (Recipe B). - Verify your device is VoLTE‑ready for the region (critical for the USA). - Save our destination links: Destinations, Esim Western Europe, Esim North America.

On arrival: - Activate data on your travel eSIM; test browsing. - Set line selection: Data = Travel eSIM; Calls = Home SIM (if using Recipe A). - Enable Wi‑Fi Calling for the line you’ll use to call. - Place a short test call and send yourself a test SMS.

Next step: choose the right regional plan and follow the setup recipe for your device. Start with Destinations to pick your eSIM for the country or region you’re visiting.