Dual‑SIM Data Steering: Best Practices for iOS & Android

31 Oct 2025

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.

Read more blogs

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

Partner Spotlight: New Reseller/Affiliate Program + Commission Tiers

The Simology affiliate program is live — and it now comes with a parallel reseller track for partners who want to package eSIMs directly. Whether you publish travel guides, run a tour agency, manage a community of digital nomads or operate a marketplace, you can earn recurring commissions by recommending our eSIMs or by reselling them under your brand flow. Today’s launch adds clear commission tiers, a practical assets kit, and an upgraded tracking dashboard so you always know what’s working. You’ll also get deep links to our most-booked plans, including Esim United States, Esim France, Esim Italy, Esim Spain and regional bundles like Esim North America and Esim Western Europe. If you serve travellers, it’s an easy value-add: reliable connectivity, instant activation, and plans across our global Destinations. Below you’ll find eligibility, how commissions work, what’s in the kit, and quick steps to apply.Who the program is for (eligibility at a glance)You’re a great fit if you reach travellers or handle travel-related transactions. Typical partners include: - Content creators, publishers, bloggers, and comparison sites - Travel agents, tour operators, OTAs, airlines and rail - Fintech, banking, insurance and loyalty programmes with travel benefits - Co‑working spaces, coliving, and remote‑work communities - Student travel organisations and international education providers - Events, conferences, and destination marketing organisationsEligibility basics: - You have a live website, app, email list, or social channel with real audience reach - Your content aligns with brand‑safe standards (no misleading claims, no adult or harmful content) - You can support simple tracking (links and, for resellers, order reporting) - You agree to avoid false discounts or coupon misuseIf you’re a company seeking volume pricing, white‑label or managed onboarding, see our enterprise options under For Business.Two pathways: Affiliate vs ResellerChoose the model that matches how you engage your audience.Affiliate (recommend and refer): - Share trackable links or codes - We handle checkout, activation and support - You earn a commission on completed orders - Best for publishers, creators and communitiesReseller (package and sell): - You sell Simology eSIMs within your own flow - You set your margin on top of partner pricing - We provide fulfilment and network connectivity - Best for agencies, marketplaces and B2B bundlesNot sure? Start as an affiliate for speed, then layer on reseller later if you need deeper integration or custom margins.Commission tiers explainedWe’ve introduced transparent tiers so you can plan campaigns and forecast revenue. Tiers are assessed by paid orders per calendar month. Rates below apply to the order value excluding taxes and fees.Tier 1 (0–49 paid orders/month): 8% commission per orderTier 2 (50–199): 10% commission per orderTier 3 (200–499): 12% commission per orderTier 4 (500+): 15% commission per orderKey definitions: - Qualified order: A paid eSIM order that is not refunded or flagged as fraud within the validation window. - Attribution: Last‑click by default via your tracking link; coupon‑code attribution is supported where enabled. - Cookie window: 30 days (the click must precede purchase within 30 days). - Payout schedule: Monthly, after validation (typically within 30 days following month‑end). - Currency and method: Paid in your selected currency where available; standard options include bank transfer or PayPal.Reseller margins: - Resellers receive partner buy rates and set retail pricing. Effective margin depends on your chosen sell price. - Volume discounts may apply for high‑commitment partners. Speak to us via For Business.Note: Rates and terms may evolve; the current schedule is always available in your partner account.Your toolkit: assets kit + tracking dashboardLaunch fast with a lightweight toolkit designed for real‑world travel publishing.Assets kit highlights: - Deep links to top products: Esim United States, Esim France, Esim Italy, Esim Spain, Esim Western Europe, Esim North America, and the full Destinations index - Copy blocks and CTAs (short, medium, long) for articles, emails and in‑app prompts - “Recommended by” badges and lightweight banners (mobile‑first) - Pre‑approved product blurbs and plan FAQs to cut research time - Coupon codes (where assigned) and usage guidelinesTracking dashboard features: - Real‑time clicks, orders, conversion rate and average order value - Pending, approved and paid commission summaries - Top‑performing links and pages (identify what to scale) - SubID tracking for placements and channels (e.g., “newsletter‑oct”, “yt‑video‑italy”) - Deep‑link builder and coupon‑code mapping - Exportable reports for finance and campaign wrap‑upsWant a preview? You’ll find sample dashboard screenshots and assets in the Partner Hub.How to apply (and go live in under 48 hours)Apply in minutes; approval typically takes 1–2 business days.Step‑by‑step: 1) Visit the Partner Hub and choose Affiliate or Reseller.2) Complete the application (business details, channels, estimated volumes).3) On approval, access your dashboard, links/codes, and the assets kit.4) Add links to high‑intent pages (e.g., “How to get data in Italy” → Esim Italy).5) Publish your first placements and test a live order with your link.6) Monitor performance and iterate placements weekly.Launch checklist (copy/paste): - Add at least one deep link per top country you cover (US, France, Italy, Spain) - Place a regional bundle link where applicable (e.g., Esim Western Europe or Esim North America) - Include a short “How eSIM works” explainer and your link in relevant guides - Add your link to email footers and trip‑planning checklists - Create a coupon‑code callout above the fold (if you have a code) - Set up SubIDs for each placement to see what convertsWhat to promote first (data‑backed starting points)The fastest wins usually come from linking directly from country or region guides to the matching eSIM page. Use: - USA itineraries, work trips and event coverage → Esim United States - European city breaks and rail passes → Esim Western Europe - Schengen trips and language/culture articles → Esim France, Esim Italy, Esim Spain - Cross‑border North American travel (US + Canada + Mexico) → Esim North America - Destination pages outside your core beat → link to the full DestinationsPro tips: - Put your link where travellers actually decide: packing lists, SIM/eSIM sections, day‑1 arrival tips, and airport transfer posts. - Match link intent to plan duration (weekend city breaks vs multi‑week itineraries). - For video, add the link in the first two lines of the description and on‑screen lower‑thirds. - Use SubIDs to A/B test “Buy now” vs “Get eSIM set up in 2 minutes” CTAs. - Seasonal spikes are real; schedule refreshes before summer, winter holidays, and major events.Compliance and brand notes (quick but important)To keep conversions high and user trust intact: - Don’t promise “unlimited” where a plan is fair‑use; use the product’s actual wording. - Avoid price claims that can go out of date; prefer “from” pricing or link to live prices. - If you publish discounts, stick to your assigned code and the live terms in the dashboard. - Represent eSIM device support accurately; remind users to check device compatibility before purchase. - For queries about brand use or co‑branded assets, check the guidelines in the Partner Hub.For agencies and teamsWorking with multiple travellers or corporate itineraries? We can help set standards across your organisation: - Centralised reporting and multi‑seat access - Curated assets for your destinations portfolio - Optional reseller pricing for packaged trips - Dedicated support for integrations and bulk queriesIf this sounds like you, start on the partner track and then speak with our team via For Business about custom arrangements.Frequently asked questions1) How are commissions calculated in the Simology affiliate program?Commission is a percentage of the order value excluding taxes and fees, based on your tier for that month. An order becomes payable after the validation window (to account for refunds or fraud checks). Your dashboard shows pending, approved and paid amounts.2) What is the attribution model and cookie length?We use last‑click attribution for tracked links with a 30‑day cookie. If coupon‑code attribution is enabled on your account, eligible orders using your code will credit you even without a tracked click (subject to programme rules).3) Can I join as both affiliate and reseller?Yes. Many partners start as affiliates for simplicity, then add reseller once they’re ready to package eSIMs in their own flow. Each track has distinct terms; you’ll see both in your partner area.4) When and how do I get paid?Payouts are issued monthly after the validation window closes, typically within 30 days following month‑end. You can choose a supported payout method (e.g., bank transfer or PayPal) and set your preferred currency where available.5) Are there any traffic restrictions?We welcome organic content, email, and compliant paid traffic. Prohibited sources include misleading ads, spam, incentivised clicks that misrepresent the offer, and any content that breaches brand‑safety guidelines. Full rules are in the Partner Hub.6) Which pages convert best?Deep links to specific plan pages tend to outperform generic home links. Popular starters include Esim United States, Esim Western Europe, Esim North America, plus country pages like Esim France, Esim Italy and Esim Spain. For broader coverage, use the Destinations index.Why partners choose SimologyTraveller‑first plans with instant activation and robust coverageClear, competitive commission tiers and on‑time payoutsDeep linking and SubID structure for serious optimisationAssets you can ship today — no long creative cyclesGlobal footprint so one partnership covers your audience worldwideNext step: Apply now via the Simology Partner Hub and get your links and assets within days.

30 Oct 2025

APN, IMS & Carrier Services: The Hidden Settings That Control Your Data

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 careIf 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 AndroidiPhone (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 guideUse this simple flow when something breaks after installing a SIM/eSIM or when roaming:Symptoms: “Connected without internet” or pages time outFirst: 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 CallingCheck 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 failingEnsure 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 roamingVoLTE (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)Confirm your plan is active and has data balance.Ensure the correct line/eSIM is set for Mobile Data and Calls (dual‑SIM phones).Turn Data Roaming on when abroad.Preferred network mode: 4G/5G Auto.APN: Select the profile provided by your carrier/eSIM. If missing, add it exactly as given.Toggle Airplane mode off/on; then reboot.Update Carrier Services (Android) or accept Carrier Settings Update (iOS).Check IMS registration status (Android). If “Not registered”, ensure VoLTE is enabled and try a different local network if allowed.Clear Carrier Services storage (Android) and reopen your messaging app if RCS/SMS is flaky.Remove and re‑add the eSIM profile if issues began right after installation.Reset APN to default (Android), then re‑select the correct APN.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 destinationPick 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.FAQsWhat 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 lineAPN 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.

30 Oct 2025