If you do not need your home number abroad, switch the home SIM off. If you need it for bank codes or calls, leave it on and make sure it cannot use mobile data.
Choose which SIM uses mobile data
- Install Atli before departure. Do this on reliable wifi, then leave the Atli line off until you arrive. The pre-travel phone checklist covers the other jobs worth doing before the flight.
- Choose Atli for mobile data when you arrive. On iPhone, open Settings, Cellular, then Cellular Data. On Android, look under Settings, Network and internet or Connections, then SIMs or SIM manager. Menu names vary by brand.
- Turn Data Roaming on for Atli. A travel eSIM normally needs this setting to reach its partner network. It does not add a separate Atli roaming fee.
- Turn Data Roaming off for the home SIM. This blocks cellular data roaming on that line, including background app traffic.
- Disable automatic data switching. On iPhone, turn off Allow Cellular Data Switching. On Android, turn off any option that switches mobile data automatically or uses another SIM for data during calls.
- Choose how calls and texts should behave. Keep the home SIM active only if you need the number. Set calls to Ask Every Time where available, so one tap does not place an expensive call on the wrong line.
If your phone does not show both lines, start with the eSIM compatibility check.
Turning off data roaming only stops data
Turning off data roaming on the home SIM stops its roaming data. It does not make the whole line free. Your carrier may still charge for:
- calls you make or answer;
- SMS or MMS you send, and sometimes messages you receive;
- listening to voicemail;
- Wi-Fi Calling, depending on the number called and your plan;
- a daily roaming pass triggered before you changed the settings;
- a smartwatch, tablet, or second phone on the same account.
Keeping your home SIM active
Leave it on if you need bank codes, calls to your home number, or carrier SMS. Whether incoming messages cost money depends on the carrier and plan.
Turn the home SIM off if you do not need it. WhatsApp and Telegram still work over Atli data with the number already registered to those apps. SMS codes and cellular calls to your home number will not reach the phone until you switch the home SIM back on.
For a closer look at using both lines, read the Dual SIM travel guide.
The cost of a two-week roaming pass
AT&T and Verizon both list a $12 daily charge per line for most covered international destinations as of August 2026. A pass used on 14 days can therefore reach $168 for one phone. AT&T caps land and air charges at ten daily fees per line in a billing period; other limits and triggers differ by carrier.
A travel eSIM is prepaid. You see its price and allowance before buying it, but it does not include your home number, calls, or SMS. Compare its price with the full cost of your carrier’s roaming plan, or use the eSIM vs roaming breakdown to compare the two approaches.
If your plan already includes roaming
Eligible subscriptions from the EU and European Economic Area generally use domestic rates across the Roam Like at Home area. Ukraine and Moldova joined that area on 1 January 2026. Fair-use data limits can still apply, and special services or non-terrestrial networks may cost extra.
The rule follows the SIM and its plan, not the travel destination alone. A visitor with a SIM from elsewhere does not gain EU roaming terms simply by arriving in Europe.
Atli is data-only
Atli is data-only. It supplies no phone number, SMS, or cellular voice service. Buy and install it through WhatsApp or Telegram, then let it handle mobile data while your home SIM is either off or restricted to the services you choose.
You install the Atli eSIM profile once. Data plans expire, but the profile does not. A later plan is added to the same eSIM automatically, so keep it installed after the trip.
Prices differ between providers on the same route. The Holafly and Saily comparisons put the same plans side by side.
Checked against Apple and Google setup guidance, AT&T and Verizon international-pass terms, EU roaming guidance, and Atli’s current service details, August 2026. Check your carrier’s terms before travel.
