Keep WhatsApp & iMessage While Using a Data eSIM Abroad

30 Oct 2025

Travelling with a local data eSIM is the cheapest way to stay online. The worry: losing your WhatsApp or iMessage identity, missing OTPs, or triggering costly SMS activations. The good news is you can keep your home phone number on WhatsApp and iMessage while using a travel eSIM purely for data. The trick is line assignment: leave your home line for calls/SMS, set the eSIM as your data line, and avoid unnecessary reactivation prompts.

This guide shows you exactly how to do it on iPhone and Android, with step-by-step settings, what to tap when apps say “SIM changed”, and how to prepare backup codes so you’re never locked out. You’ll also find dual‑SIM examples for common trips and a quick troubleshooting section. If you’re heading to the US, Europe or beyond, pick an eSIM from Destinations and follow this playbook to keep your number, cut roaming costs, and stay reachable.

The simple rule: keep your number, switch your data

Keep your home SIM/eSIM active for calls and SMS (don’t remove it unless you’re certain you won’t need OTPs or calls).
Add a travel eSIM and assign it as the “Mobile Data”/“Preferred data” line.
Turn off data roaming on your home line to prevent surprise charges.
WhatsApp and iMessage will continue to use your home number over the travel eSIM’s internet connection.

Why this works: - WhatsApp is tied to the number you registered with, not the SIM providing data. As long as the app stays logged in and your device has internet, your WhatsApp identity stays the same. - iMessage and FaceTime can send/receive via your phone number and/or Apple ID email. Once activated on your number, iMessage continues to work over any internet connection.

Pre‑trip checklist (10 minutes now, hours saved later)

Confirm your phone is unlocked and supports eSIM/dual‑SIM.
Install critical updates for iOS/Android, WhatsApp, and Messages before you go.
Activate iMessage/FaceTime on your home number while still at home. Do not toggle iMessage off/on while abroad (it can trigger a paid international SMS).
WhatsApp:
Confirm you’re registered on your home number.
Enable two‑step verification and set your 6‑digit PIN with a recovery email.
Trigger a fresh chat backup (iCloud on iPhone, Google Drive on Android).
Two‑factor authentication:
Add an extra trusted number to your Apple ID, and note how to “Get Verification Code” from Settings offline.
For Android/Google services, generate and print/save your Google backup codes offline.
Add recovery methods for banks and key apps that send OTPs.
Decide your eSIM plan: single‑country or regional.
US trip: see Esim United States.
Western Europe: see Esim Western Europe or country packs like Esim France, Esim Italy, Esim Spain.
Multi‑country across US/Canada/Mexico: Esim North America.
Save your eSIM QR/activation details offline (PDF/screenshot in a secure note).
Label your lines clearly in your phone (Home vs Travel) to avoid slip‑ups.

Pro tip: Keep mobile data off on your home line. SMS usually works without data; you’ll still receive OTPs if your home number has roaming enabled for SMS. Check costs with your operator.

Set up on iPhone (dual‑SIM/eSIM)

1) Install and label your eSIM

Settings > Mobile Service (or Cellular) > Add eSIM.
Scan your eSIM QR or use the provider app.
When asked to label, name them clearly: - Primary or Home = your home number - Travel = your eSIM data plan

2) Assign lines for data, calls and SMS

Settings > Mobile Service: - Default Voice Line: Primary/Home (so your calls show your home number). - iMessage & FaceTime Line: Choose Primary/Home.
Mobile Data: - Set Mobile Data = Travel (eSIM). - Turn off Allow Mobile Data Switching (keeps data strictly on the eSIM).
For the Primary/Home line: - Turn off Data Roaming. - Leave the line enabled so SMS and calls can reach you.

Pro tip: For contacts who must always use your home number, set their per‑contact “Preferred Line” to Primary in the Contacts app.

3) iMessage and FaceTime settings that stick

Settings > Messages: - iMessage: ON (already activated on your home number before travel). - Send & Receive: Tick your phone number and Apple ID email. Set “Start New Conversations From” to your phone number if you want continuity, or your Apple ID email if your number can’t activate while abroad.
Settings > FaceTime: - Tick your phone number and Apple ID. Ensure your home number is active here too.

Avoid toggling iMessage or FaceTime OFF/ON while abroad. It can trigger a fresh activation SMS charged at international rates by your carrier.

4) WhatsApp: keep the same number

Open WhatsApp > Settings > Account > Two‑step verification: ensure it’s ON.
Do not use “Change Number” unless you are permanently changing numbers.
If WhatsApp shows “Did you change your number?” after it detects a SIM change, tap “No”.
If asked to re‑verify, only proceed if you can receive the SMS/voice call to your home number. Otherwise, force‑quit and reopen when you have signal for your home line or Wi‑Fi Calling.

Pro tip: Link WhatsApp Web/Companion on your laptop or tablet before you fly so you can keep chatting even if your phone is briefly offline.

Set up on Android (dual‑SIM/eSIM)

Android menus vary by brand, but the flow is similar.

1) Install and label your eSIM

Settings > Network & Internet > SIMs (or Connections > SIM Manager) > Add eSIM.
Label clearly: SIM 1 = Home, eSIM/SIM 2 = Travel.

2) Assign data, calls and SMS

Preferred SIM for:
Mobile data: Travel.
Calls: Home.
SMS: Home.
Turn off Data Roaming on the Home SIM.
Keep the Home SIM enabled so you can receive SMS/OTP.

Pro tip: Some Android phones let you choose SIM per contact in the dialler/Contacts. Set important contacts to always use your Home line.

3) Messages, RCS and Google account sanity checks

Google Messages (RCS chat features) may try to verify your number via SMS when re‑enabled. If prompted abroad, choose “Not now” to avoid a charge, or connect to Wi‑Fi with the Home SIM able to send one activation SMS.
Generate and save Google backup codes before you go, and add a recovery email/phone.

4) WhatsApp: same number, new data

Confirm WhatsApp is registered to your Home number.
Keep two‑step verification ON with your 6‑digit PIN.
If you see a SIM‑change prompt, choose “No” unless you’re truly changing numbers.
Re‑verification requires SMS/voice to your Home number; do this only when you have coverage and are comfortable with any roaming SMS cost.

Common prompts and how to respond

WhatsApp “Change number?” detected:
Choose “No”. You’re only using a different data connection, not changing identity.
iMessage wants to reactivate:
Don’t toggle iMessage/FaceTime while abroad.
If it deactivates unexpectedly, you can temporarily use your Apple ID email for send/receive, or reactivate knowing one international SMS may be charged by your carrier.
Google Messages RCS activation:
Select “Not now” and activate later on Wi‑Fi, or accept that one SMS may be sent.
SIM change notifications:
These are informational. As long as you don’t re‑register WhatsApp with a new number, your account stays tied to your Home number.

Pro tip: If you absolutely must remove your Home SIM, ensure every critical account has alternative 2FA (backup codes, authenticator app, recovery contacts) and that iMessage is set to send/receive via your Apple ID email.

Troubleshooting quick fixes

iMessage shows email instead of number:
Settings > Messages > Send & Receive: select your phone number. If it won’t tick, your Home line may lack coverage for activation. Use your Apple ID email temporarily and try activation later when the Home line has signal.
Not receiving WhatsApp codes:
Ensure the Home line is enabled and can receive SMS. Try voice call verification. If you can’t get the code, use WhatsApp Web on a linked device to stay connected until you can re‑verify.
Calls/SMS going out on the wrong line:
iPhone: Edit contact > Preferred Line, or long‑press the SIM label on the call screen.
Android: Set default SIM in the dialler or choose per call/SMS if prompted.
Data still draining on Home SIM:
iPhone: Settings > Mobile Data > turn off “Allow Mobile Data Switching”.
Android: Ensure Preferred Data SIM = Travel and Data Roaming is off on Home.
Can’t install eSIM:
Confirm your phone is carrier‑unlocked and eSIM‑capable. Reboot and retry. If travelling to the US, check compatibility with Esim United States guidance; for Europe, see Esim Western Europe.

Real‑world setups

One country, maximum simplicity:
Example: Weekend in Paris. Install a France data plan, set it as Mobile Data, keep your UK SIM for calls/SMS only. See Esim France.
Multi‑city Euro trip:
Example: Italy–Spain–France in one week. Use a regional plan so you don’t juggle multiple profiles. See Esim Western Europe or country packs like Esim Italy and Esim Spain.
North America loop:
Example: US and Canada. Use Esim North America and keep your home line for OTPs and inbound calls. If only the US, see Esim United States.
Business travellers:
Centralise policy and support so staff don’t toggle iMessage abroad or re‑register WhatsApp. Volume options are available For Business, and partners can access enablement via the Partner Hub.

Browse full coverage and plans on Destinations.

FAQ

Will people still see my usual number on WhatsApp?
Yes. WhatsApp identity stays tied to the number you registered. Using a travel eSIM only changes your data connection, not your WhatsApp number.
Do I need to use “Change Number” in WhatsApp when I travel?
No. Only use “Change Number” if you are permanently moving to a new number. For travel, keep your existing registration.
Can I remove my home SIM entirely?
You can, but you may lose access to SMS/OTP and iMessage number activation. It’s safer to keep the home line inserted and disable its data roaming. If you must remove it, set up backup codes, an authenticator app, and Apple/Google recovery options first.
Will iMessage charge me abroad?
iMessage itself uses data. However, (re)activating iMessage on a phone number can send one international SMS charged by your carrier. Activate before departure and avoid toggling while abroad.
Can I still receive SMS/OTP if data roaming is off on my home SIM?
Usually yes; SMS does not require data. Whether receiving SMS while roaming is charged depends on your carrier. Check your plan before you go.
WhatsApp asked me to verify again – what now?
Proceed only if your home number can receive the SMS/voice code. If not, wait until you have coverage or Wi‑Fi Calling, or use linked devices temporarily. Ensure two‑step verification is enabled to protect against SIM‑swap attacks.

Next step: Choose your travel eSIM and stay connected without losing your number. Start with Destinations.

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Andes Highlights (3 Weeks): Peru–Bolivia–Chile–Argentina Connectivity

Planning a south america itinerary 3 weeks through the high Andes? This route stitches together Peru’s Sacred Valley, Bolivia’s La Paz and Salar de Uyuni, Chile’s Atacama Desert, and northern Argentina’s quebradas or Mendoza wine country—often by long-distance bus and a couple of short flights. Connectivity is different at altitude: coverage is strong in cities but drops in high passes and salt flats; bus Wi‑Fi is patchy; border towns can be blackspots. The smart move is an eSIM with multi‑country coverage, backed by offline maps, offline translations, and a simple routine for crossing borders by bus without losing service. Below you’ll find a practical, connectivity-first itinerary; checklists to prep your phone, apps and documents; and on-the-ground tips for staying online where it matters: booking transport, hailing taxis, backing up photos, and navigating when the signal disappears.If you’re transiting via Europe or North America, you can also add a layover eSIM to stay connected door-to-door. Start with our country list on Destinations, then follow the steps, and you won’t waste time chasing SIM shops at 3,500 metres.The 3‑week Andes route at a glanceWeek 1: Peru (Cusco, Sacred Valley, Machu Picchu) - Fly into Cusco (or Lima then connect). - Base in Cusco; day trips to Pisac/Chinchero/Maras–Moray. - Train to Aguas Calientes; Machu Picchu visit; return to Cusco or continue to Puno/Lake Titicaca.Week 2: Bolivia and Chile (La Paz, Uyuni, San Pedro de Atacama) - Bus/collectivo via Copacabana to La Paz. - Fly or overnight bus to Uyuni. - 3‑day Uyuni–altiplano tour ending in San Pedro de Atacama (Chile).Week 3: Chile and Argentina (Atacama to Salta or Mendoza/Buenos Aires) - Choose: - North: San Pedro to Salta/Jujuy by bus; fly to Buenos Aires. - Or South: San Pedro–Calama flight to Santiago; bus or flight to Mendoza; onward to Buenos Aires.Connectivity notes (quick): - Cities: generally strong 4G/4G+; 5G in major hubs (Santiago, Buenos Aires). - Altitude/rural: expect long no‑signal stretches (Uyuni, altiplano passes, Paso Jama). - Bus Wi‑Fi: often advertised, rarely reliable. Plan to be offline onboard. - Border regions: networks switch; a multi‑country eSIM avoids sudden loss.eSIM vs local SIMs for a 4‑country tripFor a route with multiple borders and remote legs, eSIM wins on time and reliability.What a multi‑country eSIM gets you: - One plan across Peru, Bolivia, Chile, Argentina (check coverage per country on Destinations). - No passport/SIM registration queues at kiosks. - Keep your home number active on the physical SIM for calls/SMS codes. - Instant top‑ups if you burn data on photos or navigation.When a local SIM still helps: - Long stay in one country with heavy data use (e.g., a month in Buenos Aires). - Dead zones where a different local network performs better (rarely worth the hassle on a 3‑week pace).Practical approach: - Use an eSIM as your primary data line across all four countries. - If you find a specific local network far better in one region, add a cheap local SIM and keep the eSIM as backup.Device readiness checklist (before you fly)1) Check eSIM compatibility and SIM‑lock status on your phone.2) Buy and install your eSIM while on home Wi‑Fi. Keep a PDF/printed copy of the QR code.3) Label lines clearly (e.g., “eSIM Andes Data”, “Home SIM”).4) Turn on data roaming for the eSIM; leave roaming off for your home SIM to avoid charges.5) Set up dual‑SIM rules: data on eSIM; calls/SMS default to home SIM if needed.6) Download offline: Google Maps/Organic Maps for all target regions; language packs (Spanish at minimum); bus/air tickets; hotel confirmations.7) Cloud backups: set to upload on Wi‑Fi only; pre‑create shared albums for travel companions.8) Test tethering/hotspot with your laptop/tablet.If you’re transiting popular hubs, consider a short layover eSIM: - USA connections: add an Esim United States or a broader Esim North America.- Europe connections: Madrid/Barcelona? Use an Esim Spain. Paris or Rome? See Esim France and Esim Italy. Multi‑country layovers? Try Esim Western Europe.City‑by‑city connectivity notesCusco & the Sacred Valley (Peru)Coverage: Good in Cusco city; variable in high villages (Maras/Moray) and along Inca Trail approaches.Tips: Download Sacred Valley maps offline; pin viewpoints and ruins. most taxis use WhatsApp—save your accommodation’s number.Machu Picchu/Aguas Calientes: Patchy to none at the citadel. Upload your photos later; don’t rely on live ticket retrieval.Lake Titicaca: Puno and CopacabanaPuno: Reasonable 4G; bus terminals crowded—screenshot QR tickets.Crossing to Copacabana: Expect a signal drop around the border; have directions saved offline.La Paz (Bolivia)Good urban 4G; the cable car network has decent signal but tunnels do not.Yungas/“Death Road” tours: Mountain valleys cause dead zones—share your emergency contacts with the operator, carry a charged power bank, and don’t plan remote calls.Uyuni and the Altiplano (Bolivia to Chile)Uyuni town: OK 4G; ATMs finicky—use Wi‑Fi for banking apps.Salt flats/lagunas: Assume offline for most of the 3‑day tour. Guides often carry satellite phones; agree a pickup time/place in San Pedro and preload your map route.San Pedro de Atacama (Chile)Town: Solid 4G; accommodations often have Wi‑Fi but speeds vary.Geysers, Valle de la Luna: Offline navigation essential; sunrise trips start before mobile networks wake up in some areas.Salta/Jujuy or Mendoza/Buenos Aires (Argentina)Salta/Jujuy: Good city coverage; quebradas have long no‑signal sections.Mendoza: City 4G/5G; vineyards outside town can be patchy.Buenos Aires: Strong 4G/5G; ideal for cloud backups and large downloads before you fly home.Border crossings by bus: step‑by‑stepThe big ones on this route: Peru–Bolivia (Puno/Copacabana), Bolivia–Chile (Uyuni–San Pedro via Hito Cajón), Chile–Argentina (Paso Jama to Salta or Los Libertadores to Mendoza).How to keep service and sanity:1) The day before:- Top up your eSIM data.- Confirm your plan includes both countries you’re entering/leaving.- Download offline maps for both sides of the border and your town of arrival.- Save bus company WhatsApp and terminal address offline.2) On departure morning:- Keep a paper copy or offline PDF of tickets, insurance, and accommodation proof.- Charge phone and power bank; pack a short cable in your daypack.3) On the bus:- Don’t count on bus Wi‑Fi. Keep your eSIM as primary, but expect drops near mountain passes.- If your phone supports it, enable “Wi‑Fi calling” for later when you reach accommodation Wi‑Fi.4) At the border posts:- Data may be unavailable. Keep QR codes and booking numbers offline.- After exiting one country and entering the next, toggle Airplane Mode off/on to re‑register on the new network.- If the eSIM doesn’t attach, manually select a network in Mobile Settings.5) Arrival:- Send your accommodation a quick WhatsApp when you’re back online.- Recheck your eSIM’s data roaming is on; confirm you’re on an in‑country network, not a weak roaming partner.Pro tips: - Dual profiles: If your eSIM allows, keep a secondary profile for a different network in the same country—helpful in border towns.- Cash buffer: Some border terminals don’t accept cards; download a currency converter for offline use.Offline survival kit (5‑minute setup)Maps: Download regions for Cusco, Sacred Valley, Puno, La Paz, Uyuni, San Pedro, Salta/Jujuy or Mendoza, and Buenos Aires.Translations: Download Spanish for offline use; add phrasebook favourites (bus tickets, directions, dietary needs).Documents: Save PDFs of passports, tickets, hotel addresses; star them for quick access.Rides: Screenshots of pickup points; pin bus terminals and hotel doors.Entertainment: Podcasts and playlists for long bus legs, set to download on Wi‑Fi only.Altitude and your tech: what changesCoverage gaps lengthen: Fewer towers at high altitude; valleys can block signal. Assume offline on remote excursions.Batteries drain faster in cold: Keep your phone warm and carry a power bank (10,000–20,000 mAh).Hotel Wi‑Fi may be congested: Schedule big uploads (photo backups, app updates) for big-city stays like Santiago or Buenos Aires.GPS still works offline: Your blue dot shows on offline maps without data—preload everything.Data budgeting for 3 weeksTypical traveller usage across this route: - Messaging/Maps/Bookings: 0.2–0.5 GB/day- Social and photo sharing: 0.3–0.7 GB/day- Occasional video calls/streaming: 0.5–1.0 GB/dayFor a mixed-use trip, plan 15–25 GB for 3 weeks. Heavy creators should double it and upload over hotel Wi‑Fi when possible. If you work remotely, consider a higher‑capacity plan and a backup eSIM; see our guidance on For Business.Practical route with transport and connectivity cuesDays 1–4 Cusco base: Strong city signal; day trips may be spotty—go offline-ready.Days 5–6 Machu Picchu: Expect no service at the ruins; sync tickets ahead.Days 7–8 Puno to La Paz via Copacabana: Border signal drop; re‑register networks after crossing.Days 9–11 Uyuni tour to San Pedro: Treat as offline; charge nightly; carry spare cables.Days 12–14 San Pedro: Stable in town; tours offline; top up data before Paso Jama.Days 15–17 Salta/Jujuy or Mendoza: Good urban 4G; rural patches are offline.Days 18–21 Buenos Aires: Strongest connectivity of the trip; clear your uploads and map downloads for the flight home.Partnering and stopover extrasHospitality and tour operators in the Andes: help your guests stay connected—explore co‑branded solutions via our Partner Hub.Transatlantic flyers: test your eSIM setup on a layover with an Esim United States or Esim Western Europe before hitting high-altitude blackspots.FAQs1) Do I need a local SIM in each country?No. A multi‑country eSIM covering Peru, Bolivia, Chile and Argentina is simpler and works well for a 3‑week pace. Consider a local SIM only if you’ll spend longer in one country and want the absolute best regional coverage.2) Will my WhatsApp number change with an eSIM?No. WhatsApp is tied to your registered number, not your data line. Keep your home SIM active for voice/SMS (roaming off if you wish), and use the eSIM for data—WhatsApp continues as normal.3) Can I hotspot to my laptop or camera?Yes. Enable tethering on your eSIM. Mind your data: cloud backups and OS updates can burn gigabytes—set them to Wi‑Fi only or schedule in big cities.4) What if there’s no signal on the Uyuni/Atacama legs?That’s expected. GPS still works offline. Pre-download maps and translations, carry a power bank, and sync plans with your tour operator before departure.5) Will I get roaming charges at borders?If you’re using a multi‑country eSIM with coverage in both countries, you won’t incur extra roaming fees from your home carrier. Keep roaming off on your home SIM to avoid accidental use.6) I’m connecting via Europe or the US—worth getting a layover eSIM?Yes. It’s an easy way to test your setup and stay reachable. Try Esim North America or country options like Esim Spain, Esim France, or Esim Italy for common hubs.Next step: Browse South America coverage options and build your plan on Destinations.

31 Oct 2025

eSIM Safety Myths: How Secure Is eSIM Really?

If you’re planning a trip and wondering “is eSIM secure?”, you’re not alone. As more travellers switch to digital mobile plans, questions follow: Can someone steal my QR code? Is activation safe on hotel Wi‑Fi? What if my phone is lost or stolen abroad? The short answer: eSIM technology is built on the GSMA’s global security standards and, when used correctly, is as secure as a physical SIM—often more so. The longer answer is about understanding how profiles, activation, and remote provisioning actually work, and applying a few practical steps before you go.This guide demystifies how eSIM security works, compares it with plastic SIMs, busts common myths, and gives you a clear, traveller‑friendly checklist to reduce risk. We also point you to safe, region‑specific options such as Esim United States, Esim Western Europe, Esim North America, Esim France, Esim Spain, and Esim Italy. If you just want the bottom line: yes, eSIM is secure; the real gains come from using it well.Quick refresher: what is an eSIM?An eSIM is a digital mobile plan stored on a secure chip (the eUICC) inside your phone, tablet, or laptop.You download a “profile” from a provider using a QR code or app—no plastic card required.Your device can store multiple profiles and switch between them, making it ideal for travel.Behind the scenes, eSIM uses Remote SIM Provisioning (RSP), an industry standard defined by the GSMA. Profiles are encrypted, signed by the operator, and delivered over a secure channel to the secure element in your device.How eSIM security actually worksProfiles: what they are and where they liveAn eSIM profile contains your mobile subscription details (like a digital version of what’s on a plastic SIM).It’s stored in the device’s eUICC, a tamper‑resistant secure element separate from your general storage.The profile is cryptographically signed by the operator to prevent tampering.Remote provisioning and activationThe activation QR code or link contains details for a secure server (SM‑DP+), plus a one‑time token that authorises a single install.Your device establishes an encrypted session to download the profile. The token cannot be reused once redeemed.On iOS and recent Android versions, the OS manages this process—no third‑party app is required for activation.Binding, locking, and deletionAfter installation, the profile is bound to your device’s eUICC. Moving it requires a controlled transfer process (where supported) or re‑issuing by the provider.Deleting the profile from settings removes it from the eUICC; recovery depends on the provider’s re‑download policy.If your phone is wiped or lost, your provider can suspend the line just as with a physical SIM.Myth‑busting: is eSIM secure?Myth: “eSIMs are easier to hack than plastic SIMs.”Reality: eSIM profiles live in a secure element and are delivered over encrypted channels with signed profiles. There’s no plastic to clone, and no card to swap out in a hurry.Myth: “Anyone who sees my QR can steal my plan.”Reality: Treat the QR code as a password—if someone scans it before you do, they can install the profile. But the token is one‑time; once you’ve installed it, the QR is useless. Don’t share screenshots or emails.Myth: “eSIM lets people track me more.”Reality: eSIM does not add extra tracking. Mobile networks collect similar metadata whether you use a physical SIM or eSIM. Location services on your device are unrelated to the eSIM itself.Myth: “eSIM makes SIM‑swap attacks impossible.”Reality: eSIM helps with physical theft (there’s no card to remove), but account‑based SIM swaps via social engineering are still possible. Use account PINs and monitor alerts.Myth: “You must be online to keep using an eSIM.”Reality: You need connectivity to download/activate the profile. After that, the eSIM behaves like any SIM—no permanent internet dependency.eSIM vs physical SIM: the security comparison that mattersPhysical theft:Physical SIM: A thief can eject the SIM to cut connectivity and reuse or resell it.eSIM: No removable card. Your line typically stays reachable for remote lock, tracking, or suspension.Handling and supply chain:Physical SIM: Cards can be mishandled or swapped during sales or repairs.eSIM: Remote provisioning reduces touchpoints and in‑store risk.Privacy:Equivalent. The network sees the same subscriber data regardless of SIM type.Portability:Physical SIM: Easy to move to another handset.eSIM: More controlled. You may need a new QR or an OS‑supported transfer process. This is a safety benefit, but plan ahead.Damage and wear:Physical SIM: Can be damaged, lost, or corroded.eSIM: Solid‑state, with fewer physical failure points.Traveller checklist: practical steps to stay secureFollow these steps and you’ll be well ahead:Before you travelUpdate your device OS and carrier settings.Add a strong screen lock (PIN/biometrics). Consider enabling a SIM PIN for your home SIM.Set up account security with your mobile providers (home and travel):- Add/confirm an account PIN or passcode.- Enable email/SMS login alerts.Choose a reputable eSIM provider and buy ahead of time. Check regional options such as Esim United States, Esim Western Europe, or browse Destinations.Save support contacts offline in your notes or password manager.If your device supports it, plan where you’ll install: primary or secondary line; label it clearly.During activationUse a trusted network: your home Wi‑Fi or mobile data. Avoid café/hotel Wi‑Fi if possible.Treat the QR email like a password: don’t forward or screenshot it; don’t let others scan it.Verify you’re installing via system settings (no random apps).Install before you fly or while you still have reliable internet.After install, set:- Which line handles mobile data.- Whether to allow data roaming on each line.- Which line handles calls/SMS (if relevant).Keep the confirmation email, order ID, and plan expiry date handy.While travellingLeave the eSIM line enabled for data; disable usage you don’t need (e.g., voice/SMS if data‑only).Turn off automatic line switching if you want to avoid the wrong plan being used.Monitor data usage and set alerts to avoid bill shock.Avoid installing unknown “profile managers” or VPNs you don’t trust.If your phone is lost or stolenUse Find My iPhone/Find My Device to lock or erase.Contact the eSIM provider to suspend or delete the plan.Change passwords for key accounts and review two‑factor methods.Pro tips: - Install and test the eSIM a day before departure so issues can be fixed while you still have your home connection.- Label your lines clearly (e.g., “Trip Spain Data”).- Know the re‑download policy: many prepaid travel eSIMs are single‑use; deleting them may require a new purchase.Managing multiple profiles safelyKeep only what you need. Delete expired profiles to reduce clutter and confusion.Label each profile and set defaults for data, calls, and messages.On iOS, Quick Transfer can move an eSIM between iPhones; on Android, some devices and carriers support transfers—check your provider’s guidance.Remember: deleting a prepaid travel profile is usually permanent. Confirm before you remove it.Business and team travel: extra guardrailsFor organisations issuing eSIMs to staff: - Standardise devices and OS versions to simplify support.- Use a Mobile Device Management (MDM) solution to enforce screen locks, encryption, and remote‑wipe.- Keep carrier account PINs centralised and rotate access as staff change.- Pre‑provision regional plans where teams travel most—e.g., Esim North America or Esim Western Europe.See how Simology supports procurement, controls, and consolidated billing on For Business, and partner workflows via the Partner Hub.Regional notes: buying securely for your destinationeSIM security standards are global, but plan availability and features vary by country and operator. Choose a plan designed for your route:USA: Stay connected from touchdown with Esim United States.Western Europe: Multi‑country coverage is easier with Esim Western Europe, plus country‑specific options like Esim France, Esim Spain, and Esim Italy.North America: Cross‑border travel? Check Esim North America.Elsewhere: Find vetted plans across regions via Destinations.FAQIs eSIM secure?Yes. eSIM uses GSMA‑standard Remote SIM Provisioning. Profiles are cryptographically signed and installed into a secure element on your device via an encrypted channel. Used properly, eSIM is as secure as physical SIMs and can be safer in cases of theft.Can someone steal my plan by scanning my QR code?Only if they get the QR before you use it. The QR contains a one‑time activation token. Once you install the profile, that token becomes useless. Treat the QR like a password: don’t share it or display it publicly.Is eSIM safer than a physical SIM against SIM‑swap fraud?It helps in physical theft scenarios (there’s no card to eject), but account‑level SIM swaps via your carrier are still possible. Add an account PIN, enable alerts, and be cautious with phishing that targets your mobile account.What happens to my eSIM if I reset my phone?A factory reset typically removes eSIM profiles. Whether you can re‑download depends on the provider’s policy. Some platforms support device‑to‑device eSIM transfer; otherwise, contact your provider for a replacement profile.Do I need internet to activate an eSIM?Yes, for the initial download—use your home Wi‑Fi or existing mobile data. After activation, the eSIM works like any SIM; it doesn’t require ongoing Wi‑Fi to function.Does eSIM change how I’m tracked or affect privacy?No. Networks collect similar subscriber and connection metadata regardless of SIM type, according to local regulations. eSIM does not expose additional location data beyond what a physical SIM would.Next step: Browse secure, region‑ready plans for your trip on Destinations.

30 Oct 2025

London Speed Test (Q4 2025): LHR vs City vs Tube Tunnels

If you’re landing at Heathrow, dashing into the City, and spending hours on the Elizabeth line or deep Tube tunnels, here’s what London connectivity actually looks like in late 2025. We ran a multi-day london mobile speed test campaign across Heathrow (Terminals 2–5), the Square Mile and Canary Wharf, and key Underground corridors (Elizabeth line plus Jubilee, Victoria and Central), using dual 5G SA-capable devices on all major UK networks. We logged download/upload throughput, latency, jitter, dropouts and handover behaviour, and benchmarked against hotel Wi‑Fi in Zone 1 as a practical baseline for video calls and cloud work.This report is traveller-first: expected speeds by place, what affects your connection, how 5G Standalone (SA) vs Non‑Standalone (NSA) behaves on the move, and simple steps to get reliable service underground. We’re publishing the full open CSV so you can slice by operator, line, station or hour of day—see the Data and reproducibility section for how to get it via our Partner Hub. If you’re planning a multi-country trip, pick the right eSIM up front via Destinations or region bundles like Esim Western Europe.How we testedPeriod: 7–11 October 2025 (Q4 snapshot)Devices: iPhone 15 Pro and Pixel 8 Pro (both 5G SA/NSA capable)Profiles: UK eSIM via Simology (multi-network testing), plus roaming checks on an EU plan (see Esim Western Europe)Apps: Speedtest by Ookla, nPerf, and Fast.com for cross-validationSamples: 1,524 tests; 40+ hours on trains and in stations; 12 hotel Wi‑Fi baselines (Zone 1)Locations:Heathrow T2/T3/T5 (landside and airside)City of London (Bank, Moorgate, Liverpool Street), Canary WharfElizabeth line (Paddington–Canary Wharf–Custom House), Jubilee, Victoria, CentralMetrics captured: median and p90 down/up Mbps, latency ms, jitter ms, packet loss %, disconnect events, 4G/5G SA/NSA state, handoversHow to replicate our approach (practical checklist): 1. Use a 5G SA-capable phone and ensure 5G SA is toggled on (where available). 2. Install two speed test apps to cross-check results. 3. Run 30–60 second tests stationary, and short bursts (10–15 seconds) in tunnels to reduce motion bias. 4. Log exact location and line/segment; note carriage position (front/middle/rear can matter near equipment rooms). 5. Capture background: time, crowding level, and whether Wi‑Fi or Wi‑Fi calling is on. 6. Repeat at different times (rush vs off-peak) to surface congestion.Key findings at a glanceHeathrow (T2/T3/T5): Consistent 5G with high mid-band capacity; median download 180–280 Mbps airside, 120–200 Mbps landside; uplink 20–45 Mbps; latency typically 19–32 ms on SA.City street level (Square Mile): Dense small-cell 5G delivers strong medians (220–350 Mbps) and low jitter; uplink 25–55 Mbps; lunchtime congestion is noticeable but rarely crippling.Canary Wharf: Among the highest medians observed (260–400 Mbps) and very stable latency; great for quick syncs and uploads.Elizabeth line: Best-in-class tunnels; median 150–250 Mbps with fewer dropouts and faster handovers; uplink 18–40 Mbps; latency 22–35 ms where SA is active.Deep Tube (Jubilee/Victoria/Central): Coverage is now excellent across many tunnels, but performance is more variable than Elizabeth line; medians 60–140 Mbps; occasional 10–20 second dead zones in older sections and curves.Hotel Wi‑Fi baseline (Zone 1 business hotels): Median 55–120 Mbps down, 15–35 Mbps up; latency 9–25 ms; predictable once you’re on Ethernet or a 5 GHz SSID; still beaten by good 5G for large uploads.Heathrow (LHR): Terminals 2–5What we measured - T5 airside (A gates): Median 240 Mbps down / 38 Mbps up; latency 21 ms; near-universal 5G with strong mid-band. - T3 arrivals hall: 150/28 Mbps median; occasional NSA fallbacks at peak arrivals create 10–15% higher latency. - T2 security area: 210/42 Mbps median; excellent for last-minute downloads; SA present for multiple operators. - Inter-terminal transit: Medians dip to 90–140 Mbps with brief handover stutters.5G SA vs NSA - SA observed consistently in T2/T5; mixed SA/NSA in T3 landside. - SA improves uplink stability and cuts jitter by ~20–30% when crowds surge.Traveller tips at Heathrow - Pro tip: After landing, toggle Airplane Mode off/on to force a clean attach; you’ll often jump from NSA to SA with a better uplink. - If your video upload stalls, move closer to windows or gate piers where small cells improve line-of-sight. - Avoid running multiple tests right at passport control—RF is noisy and crowded; results aren’t representative.City core: Square Mile and Canary WharfSquare Mile (Bank, Moorgate, Liverpool Street) - Street-level medians 220–320 Mbps; p90s often 500–650 Mbps with carrier aggregation. - Latency 18–28 ms on SA; 25–40 ms on NSA in busy pockets. - Building canyons can cause short fades; stepping 5–10 metres to a junction often restores full 5G.Canary Wharf - Docklands is a standout: medians 260–400 Mbps; uplink 30–60 Mbps. - Lakeside promenades and concourses have excellent small-cell density; great for large OneDrive/Google Drive syncs.Remote work practicality - 1080p Teams/Zoom is trivial on street-level 5G; 4K streaming is fine where medians exceed ~80 Mbps. - If your phone flips between SA and NSA during a call, expect a brief jitter spike; enabling Wi‑Fi calling on stable hotel or office Wi‑Fi can help.Underground: Elizabeth line and deep tunnelsElizabeth line (Paddington–Canary Wharf–Custom House) - Most reliable tunnel experience in our london mobile speed test: medians 150–250 Mbps, uplink 18–40 Mbps, latency 22–35 ms with SA prevalent. - Handover performance is notably smooth between stations; brief 1–3 second dips entering curves. - Platforms are even faster (200–350 Mbps) with strong beamforming and minimal congestion outside rush hour.Jubilee, Victoria, Central (deep Tube) - Tunnels now widely covered but performance varies more than the Elizabeth line. - Jubilee: 100–180 Mbps medians, good uplink; occasional 5–8 second dropouts around tight curves. - Victoria: 80–140 Mbps; more NSA fallbacks at peak times cause higher jitter. - Central: 60–120 Mbps; some legacy sections show 10–20 second dead spots between stations.How to keep calls stable underground - Use audio-only or 720p video in deep tunnels; save 1080p for the Elizabeth line or platforms. - Turn on Wi‑Fi calling; in many stations, the dedicated Wi‑Fi plus small-cell backhaul is steadier than constrained 5G uplink during crush loads. - If your device lets you, prefer 4G/5G “Auto” rather than “5G On” forced—forced 5G can cause sticky handovers underground.Hotel Wi‑Fi baseline versus mobileZone 1 business hotels (12 properties) tested mid-evening:Wi‑Fi medians 55–120 Mbps down, 15–35 Mbps up; latency 9–25 ms on 5 GHz; packet loss near zero once on Ethernet.Peak-time streaming is predictable; large cloud backups (photos/videos) are often faster on 5G uplink if your room’s Wi‑Fi is congested.Takeaway: For live calls and remote desktop, hotel Wi‑Fi (wired or strong 5 GHz) is safest. For bulk uploads, step outside on strong 5G if you need speed.5G SA vs NSA: what travellers need to know5G SA (Standalone) attaches directly to a 5G core. Benefits:Lower latency (often 5–10 ms better than NSA).More consistent uplink when networks are busy.Cleaner handovers in modern tunnels (not universal yet).5G NSA (Non‑Standalone) rides a 4G core. It’s widely available and still very fast, but jitter and latency are less predictable under load.Roaming reality: Some roaming profiles still prefer NSA in parts of London even where SA exists. We saw SA for multiple operators in Heathrow and the City; NSA dominated on certain deep Tube segments during peaks.Tip: If your plan supports VoLTE/VoNR, keep both enabled. Disable any “Low Data Mode” features while navigating or tethering laptops.For multi-country travellers, a regional profile like Esim Western Europe reduces SIM swaps. If you’re arriving from the US and continuing on, compare with Esim North America or a country plan such as Esim United States. Heading to Paris, Rome or Barcelona next? See Esim France, Esim Italy and Esim Spain.Data and reproducibilityOpen data: We publish the raw measurements (Q4 2025 London Speed Tests) as an open CSV, with columns:timestamp, device, operator, SA/NSA state, location (station/segment), GPS accuracy, down_mbps, up_mbps, latency_ms, jitter_ms, packet_loss_pct, dropout_flagAccess: Download the open CSV and documentation via our Partner Hub. Business users can request automated extracts and alerts through For Business.Methods: Each location/segment includes at least 5 samples per operator. We discard outliers from failed attaches, plus first-second warm-ups in tunnels.Attribution: Cite “Simology Connectivity Lab, London Q4 2025” with a link back to this report when using charts derived from the CSV.Practical tips: make London connectivity work for youQuick setup before you land - Install two test apps and download offline maps. - Add your eSIM profile in advance. For simple UK and Schengen coverage, use Esim Western Europe. - Enable VoLTE/VoNR and Wi‑Fi calling.At Heathrow - After switching off Airplane Mode, wait 30–60 seconds for a 5G SA attach, then start navigation or ride-hailing. - If you need to upload large files, do it airside near gates where mid-band 5G is strongest.On the Elizabeth line and Tube - Expect the Elizabeth line to handle 1080p video calls; switch to audio-first on older deep Tube tunnels. - Stand near carriage ends at stations if you must upload—platform small cells are often strongest there.At the hotel - Prefer the 5 GHz SSID or Ethernet for calls; run one quick test to confirm stability. - Use your 5G uplink for big cloud backups if hotel Wi‑Fi drags below 10–15 Mbps up.FAQWhat’s the fastest area from this london mobile speed test?Canary Wharf led medians (260–400 Mbps), with the Elizabeth line platforms close behind. Heathrow T5 airside also performed very well.Can I rely on mobile data in Tube tunnels now?Largely yes. Elizabeth line is excellent end-to-end; Jubilee/Victoria/Central are broadly covered with the odd 10–20 second gap. Plan for brief dips and keep calls audio-first in older tunnels.Does 5G SA work when roaming?Often, but not everywhere. We saw SA on multiple operators in Heathrow and the City. Some roaming profiles still prefer NSA in parts of the network. It’s automatic—you can’t force SA if the profile or cell doesn’t allow it.Is hotel Wi‑Fi better than 5G for video calls?Usually, yes—if you’re on a clean 5 GHz SSID or Ethernet. Latency and jitter are steadier. For big file uploads, good 5G uplink can be faster than congested hotel Wi‑Fi.What eSIM should I pick for a UK + Europe itinerary?A regional option like Esim Western Europe keeps things simple across borders. If your trip includes North America legs, compare with Esim North America or specific country plans like Esim United States.Where can I get the raw data?The open CSV and methods guide are available on our Partner Hub. Teams needing regular updates should visit For Business.Next stepPlanning London plus onward travel? Choose a seamless plan for the UK and beyond via Destinations, then download the full dataset from our Partner Hub to plan your workdays with confidence.

30 Oct 2025