You have set up your travel eSIM and it is installed on your device. The next question is how to use it effectively while you are actually traveling — which line handles data, which keeps your home number available, what to turn off to prevent charges on your home SIM, and what to restore when you return. That is what this guide covers.
For background on how dual SIM technology works (DSDS, DSDV, DSDA modes), see What Is Dual SIM?. For the step-by-step eSIM installation process, see Your First Travel eSIM. For the full pre-departure checklist, see the Pre-Trip Smartphone Checklist.
The Standard Dual SIM Setup for Travel
The most common travel configuration uses two lines with clearly separated roles:
| Line | Role |
|---|---|
| Home SIM | Voice calls and SMS — keeps your home number reachable |
| Travel eSIM | Cellular data — connects to local networks at local rates |
This setup gives you two things that matter most when traveling: a data connection that does not depend on international roaming rates, and a home phone number that stays active so you can receive SMS and inbound calls.
Most travel eSIMs are data-only — they provide internet access but no phone number or SMS capability. This is by design: the data-only model covers the primary use case (internet access abroad) at lower cost, while your home SIM handles everything that requires your actual number.
If you have not yet chosen a travel eSIM plan for your destination, SimFinder Travel lists current plans with coverage, data amount, and validity period for each.
Assign Each Line to Its Job
Once your travel eSIM is installed and you are at your destination, configure the line assignments explicitly. Do not rely on the default — devices vary in which line they default to for data, and defaulting to the home SIM abroad is a costly mistake.
iPhone: Cellular Line Settings
On iPhone, go to Settings > Cellular.
Set the travel eSIM as your cellular data line:
- Tap Cellular Data
- Select the travel eSIM line
Set your home SIM as the default voice line:
- Under the line list, tap Default Voice Line
- Select your home SIM
Turn off Allow Cellular Data Switching:
- Tap Cellular Data
- Toggle Allow Cellular Data Switching to off
This last step is critical. With Allow Cellular Data Switching on, your device automatically routes data through your home SIM if the travel eSIM signal drops. Abroad, that means roaming charges on your home plan. Turn it off so the device stays on the travel eSIM for data regardless of signal fluctuation.
iMessage and FaceTime: If you use iMessage or FaceTime, check which address (phone number or Apple ID email) your messages are sent from. Go to Settings > Messages > Send & Receive and Settings > FaceTime > You Can Be Reached At. Using your Apple ID email address rather than your home number as the primary address ensures iMessage works over the travel eSIM data connection without requiring SMS delivery through your home SIM.
Android (Google Pixel): SIM Settings
- Go to Settings > Network & Internet > SIMs
- Set the travel eSIM as the Preferred SIM for data
- Set your home SIM as the Preferred SIM for calls
- Under your home SIM settings, confirm Mobile data is disabled for that line
On Pixel, you can also set a per-call preference — the device can ask which SIM to use for each outgoing call, which is useful if you want to occasionally make calls through the travel eSIM.
Samsung Galaxy: SIM Card Manager
- Go to Settings > Connections > SIM card manager
- Under Preferred SIM, set:
- Calls: home SIM
- Texts: home SIM
- Mobile data: travel eSIM
- Disable Switch to better data network if the option appears — this behaves similarly to iPhone’s Allow Cellular Data Switching and can route data back to a roaming home SIM
Receiving SMS While Traveling
If you use SMS-based two-factor authentication for banking, email, or other accounts, receiving those codes while abroad depends on your home SIM staying active in a specific configuration.
Why the Home SIM Must Stay in Voice/SMS Mode
SMS and voice registration on a mobile network are separate from data roaming. When your home SIM line is active (not disabled), your device registers with the visited network in roaming mode — this is how the network knows to route inbound calls and SMS to you even though you are not on your home carrier’s network. Data roaming is a separate toggle that controls whether the SIM can use the visited network for internet access.
The configuration that receives SMS without incurring roaming data charges:
- Home SIM line: enabled
- Data Roaming for home SIM: off
- Voice Roaming for home SIM: depends on your carrier (see below)
With this setup, your home SIM registers on the visited network for voice and SMS purposes only. SMS 2FA codes sent to your home number arrive as they would domestically.
Voice Roaming and SMS Reception
Some carriers require Voice Roaming to be explicitly turned on for the home SIM to receive inbound SMS abroad. Others include SMS reception in the default roaming registration regardless of the Voice Roaming toggle.
If you are unsure how your carrier handles this, the safe approach is to leave Voice Roaming enabled on your home SIM. Enabling Voice Roaming does not in itself incur charges — charges apply only when you actually make or receive a call. The roaming registration that enables SMS delivery does not cost anything on most carriers.
Check your home carrier’s international roaming documentation before departure. Some carriers send a welcome SMS when you land abroad that confirms your roaming registration is active; that is a reliable indicator that SMS will be received.
Wi-Fi Calling as a Fallback
If your home carrier supports Wi-Fi Calling and your device is connected to Wi-Fi, your home number may receive calls and SMS over the Wi-Fi connection rather than the cellular network. This works even with the home SIM’s cellular data disabled and voice roaming off.
Wi-Fi Calling availability varies by carrier and country. On iPhone, check Settings > Cellular > [home SIM line] > Wi-Fi Calling. On Android, check Settings > Network & Internet > SIMs > [home SIM] > Wi-Fi calling.
If your home carrier supports it and you expect to be in areas with good Wi-Fi but poor cellular coverage, enabling Wi-Fi Calling on your home SIM before departure is a reliable backup for SMS delivery.
For an alternative approach to SMS 2FA that does not depend on your home SIM being reachable at all — including before you travel — see the Pre-Trip Smartphone Checklist, which covers migrating time-sensitive accounts to an authenticator app.
Incoming Calls on Your Home Number
Your home number remains reachable while you are traveling, but answering calls on it has cost implications that depend on your home carrier’s plan.
How Inbound Roaming Calls Work
When someone calls your home number abroad, the call is routed from your home carrier to the visited network operator. You receive the call normally. The charge for this varies:
- Some plans include a number of international roaming minutes at no additional cost
- Some plans charge per-minute for incoming international roaming calls
- EU travelers with an EU SIM within the European Economic Area are covered by Roam Like at Home regulations, which eliminate additional charges for calls and data within the EEA
Because rates vary significantly by carrier and plan, check your home carrier’s international roaming rates before departure. Do not assume inbound calls are free.
Call Forwarding Before Departure
If your home carrier charges for incoming roaming calls and you want to avoid those charges, set up call forwarding before you leave. Options:
- Forward to a VoIP number: Services that provide a VoIP number can receive calls and deliver them as push notifications. The forwarded call arrives over the internet rather than the cellular network, so no roaming charges apply on the receiving end.
- Forward to voicemail: Route inbound calls directly to voicemail. You listen to messages when connected to the travel eSIM data, at no additional cost.
To set call forwarding on iPhone, go to Settings > Phone > Call Forwarding and enter the forwarding number. On Android, call forwarding is typically found in the Phone app settings under Supplementary Services or Additional Settings. The exact path varies by device manufacturer.
VoIP Apps for Free Inbound Communication
The most practical alternative for travelers who do not want to manage call forwarding is to ask regular contacts to reach them via a VoIP app. WhatsApp, FaceTime (Apple to Apple), LINE, and Messenger all route calls over the internet — they use the travel eSIM data connection and incur no carrier roaming charges.
The limitation is that only contacts who know to use the app will reach you this way. For contacts who do not use any VoIP app, call forwarding to voicemail remains the cleaner solution.
What to Turn Off on Your Home SIM
Preventing unintended charges from your home SIM while using the travel eSIM requires turning off specific settings. These settings exist at the line level in your device’s cellular menu.
Data Roaming: Off
This is the most important setting. Data Roaming controls whether your home SIM can use mobile data on the visited network. With this off, your home SIM cannot incur roaming data charges even if the device briefly registers on a foreign network.
- On iPhone: Settings > Cellular > [home SIM line] > Data Roaming — off
- On Android: Settings > Network & Internet > SIMs > [home SIM] > Roaming — off
Confirm this setting before boarding your first flight. The device may have roaming on from a previous configuration.
Allow Cellular Data Switching: Off (iPhone only)
As described in the line assignment section above, this setting allows the device to automatically move data to the home SIM when the travel eSIM drops signal. Turning it off ensures the device stays on the travel eSIM for data at all times.
Location: Settings > Cellular > Cellular Data > Allow Cellular Data Switching
Mobile Data on the Home SIM Line: Off (Android)
On Android, you can disable mobile data specifically for the home SIM line without disabling the line itself. The line remains active for voice and SMS registration, but the SIM cannot use cellular data.
- On Pixel: Settings > Network & Internet > SIMs > [home SIM] > toggle Mobile data off
- On Samsung: Settings > Connections > SIM card manager > [home SIM] > toggle the data option off
What You Do Not Need to Turn Off
You do not need to disable the home SIM line entirely to prevent charges. The goal is a home SIM that remains registered on the network for voice and SMS, but cannot use roaming data. Disabling the line entirely would prevent it from receiving SMS 2FA codes, which is the opposite of what you want.
Switching Data Back to Your Home SIM
When you return home, the line assignments you configured for travel need to be reversed. Your travel eSIM is still set as the data line; your home SIM has Data Roaming off. Neither is correct for domestic use.
After Returning Home
On iPhone:
- Go to Settings > Cellular > Cellular Data
- Select your home SIM line as the data source
- Go to Settings > Cellular > [home SIM line] > Data Roaming — if you want data roaming available for future domestic roaming, turn it back on. If you are now on your home network, it does not matter — roaming applies only to foreign networks.
- Go to Settings > Cellular > Cellular Data > Allow Cellular Data Switching — you may re-enable this if you want the fallback behavior domestically
On Android:
- Go to Settings > Network & Internet > SIMs
- Change the Preferred SIM for data back to your home SIM
- Re-enable Mobile data for your home SIM line
Keeping or Removing the Travel eSIM Profile
There is no need to delete the travel eSIM immediately after returning. The profile stays dormant on your device and does not consume data or incur charges when disabled.
If you return to the same region, you may be able to reactivate the same profile or top up data through the provider’s app — faster than purchasing and installing a new plan. Check your provider’s documentation for whether the profile supports reactivation.
If the plan has fully expired and the provider does not support reactivation or top-up, you can delete the profile to keep your SIM list manageable.
To delete on iPhone: Settings > Cellular > [travel eSIM line] > Delete eSIM
To delete on Android: SIM manager settings > [travel eSIM line] > Delete or Remove
Before deleting, confirm whether the provider issues a new QR code for reinstallation at no charge. Some providers allow reinstallation from their app; others generate a new profile at additional cost. If you anticipate returning to the same destination, keeping the expired profile installed until you are ready to purchase again costs nothing.
Device Limitations
Not all devices support dual SIM operation. Understanding the constraints of your specific device prevents surprises while traveling.
iPhone
iPhones operate in DSDS mode (Dual SIM Dual Standby). Both SIMs remain on standby and can receive calls and SMS simultaneously. During an active call on one line, data on the other line pauses — so a call on the home SIM briefly interrupts data on the travel eSIM.
iPhones do not support DSDA (Dual SIM Dual Active), which would keep both lines fully independent. For most travel use cases — background navigation data plus home number availability for SMS — DSDS behavior is sufficient.
Dual SIM configurations by model:
- iPhone XS, XS Max, XR (2018) and later: physical SIM + eSIM
- iPhone 13 series and later (including SE 3rd generation): dual eSIM (two eSIM profiles active simultaneously, no physical SIM required)
- iPhone 14 and later sold in the United States: eSIM-only, no physical SIM slot
If your home carrier provides only a physical SIM and you have an iPhone 14 US model with no physical SIM slot, you will need to ask your home carrier if they can convert your physical SIM to an eSIM before departure.
Google Pixel
- Pixel 3a and later: physical SIM + eSIM (DSDS)
- Pixel 7 and Pixel 7 Pro (2022) and later: dual eSIM — two eSIM profiles active simultaneously, enabled by MEP (Multiple Enabled Profiles) introduced in GSMA SGP.22 v3.0
Pixel 10, 10 Pro, and 10 Pro XL sold in the United States are eSIM-only. The Pixel 10 Pro Fold retains a physical SIM slot.
Samsung Galaxy
Samsung Galaxy S20 and later support eSIM alongside a physical SIM on most variants. eSIM availability depends on the region and whether the device is carrier-locked — a carrier-locked Samsung may not expose the eSIM option even if the hardware supports it.
Samsung devices do not universally support dual eSIM (two simultaneous eSIM profiles). Confirm your specific model’s capabilities in Samsung’s device specifications before assuming dual eSIM is available.
Devices Without Dual SIM
Older devices with a single SIM slot and no eSIM support cannot run a dual SIM configuration. On these devices, inserting a local SIM at your destination means losing access to your home number for the duration of the trip — no SMS 2FA on the home number, no inbound calls. If this is your situation, the alternatives are: retain the home SIM and use international roaming for all connectivity, or before departure, migrate time-sensitive accounts to an authenticator app so SMS 2FA is not required while abroad.
For a comparison of all connectivity options including pocket Wi-Fi and local SIM, see 4 Ways to Stay Connected Abroad.
Frequently Asked Questions
Can I receive SMS on my home number while using a travel eSIM for data?
Yes, as long as your home SIM remains active alongside the travel eSIM. Keep Data Roaming off on your home SIM so it does not incur charges, but leave the line itself enabled — the device registers on the home carrier network in roaming mode for voice and SMS even without data roaming. Some carriers require Voice Roaming to be enabled for the home SIM to receive SMS abroad. Check your home carrier’s roaming policy before departure.
What is Allow Cellular Data Switching and should I turn it off?
Allow Cellular Data Switching (iPhone) lets your device automatically move data to your home SIM if the travel eSIM signal drops. This is useful domestically but creates a roaming charge risk when traveling — if the device switches data to your home SIM abroad, your home carrier’s international roaming data rates apply. Turn it off in Settings > Cellular > Cellular Data > Allow Cellular Data Switching when abroad with a travel eSIM.
Do I need to keep Voice Roaming on for my home SIM?
It depends on your home carrier’s policy. On many carriers, the SIM registers on the visited network for voice and SMS as long as the line is active, regardless of the Voice Roaming toggle. On others, Voice Roaming must be explicitly enabled to receive inbound calls and SMS. If you are unsure, leave Voice Roaming on — charges apply only when you make or receive calls, not when the SIM is merely registered on the network.
What happens to incoming calls on my home number while I am abroad?
Your caller dials your home number normally. Your phone rings if you are registered on a roaming network with voice roaming active. Answering typically incurs incoming international roaming charges that depend on your carrier and plan. Alternatives include call forwarding to a VoIP number before departure, or directing regular contacts to reach you via WhatsApp or another internet-based app.
Can I use dual SIM on any phone?
Not all devices support dual SIM. On iPhone, dual SIM (physical SIM + eSIM) is available on iPhone XS and later. On Android, Google Pixel 3a and later support physical SIM + eSIM; Pixel 7 and later support dual eSIM. Samsung Galaxy S20 and later support eSIM alongside a physical SIM on most variants. Older devices with a single SIM slot and no eSIM support cannot run a dual SIM setup.
Should I delete my travel eSIM after returning home?
Not necessarily. If the provider supports it, keep the profile installed for your next trip to the same region — re-enabling a saved profile is faster than purchasing and reinstalling. If the plan has expired and the provider does not allow reactivation, delete it to keep your SIM list manageable. Check your provider’s reinstall policy before deleting — some issue a new QR code at no charge; others charge for a new profile.
Related Guides
If you are still in the planning phase, these guides cover earlier steps in the process:
- What Is Dual SIM? — How DSDS, DSDV, and DSDA work, and what your device supports
- Your First Travel eSIM — Step-by-step installation on iPhone, Pixel, and Samsung
- 4 Ways to Stay Connected Abroad — Compare travel eSIM against local SIM, roaming, and pocket Wi-Fi
- How to Choose a Travel eSIM — Coverage, data volume, validity, and provider considerations
- Pre-Trip Smartphone Checklist — Staged timeline from 2 weeks before departure through arrival
- SIM Swap Fraud Guide — Why SMS 2FA has structural risks and how authenticator apps remove the dependency
To compare current travel eSIM plans for your destination, use SimFinder Travel — filter by country, data amount, and validity period.