esimple
Getting Started

Dual-SIM setup: keep your home number, use esimple for data

How to keep your home SIM for calls and SMS while esimple handles data — without surprise roaming charges.

Dual-SIM Setup: Keep Your Home Number, Use esimple for Data

The point of an eSIM for travel is that you don't have to give up your home number. Both SIMs stay active. Your home line keeps receiving calls, texts, and verification codes. The esimple eSIM handles all your data so you don't pay roaming fees.

Here's how to set that up cleanly.

The arrangement you want

  • Home SIM: voice, SMS, no mobile data, roaming off.
  • esimple eSIM: mobile data, roaming on (yes — see below), used for everything else.

This way your bank's text codes and your family's calls still reach you, but the moment any app or browser asks for data, your phone uses the esimple plan.

iPhone setup

  1. Settings → Cellular.
  2. You'll see both lines listed. Your home plan and the esimple eSIM.
  3. Tap Cellular Data at the top. Pick the esimple plan.
  4. Turn off "Allow Cellular Data Switching." This is critical. With it on, the phone falls back to your home SIM when the eSIM signal is weak — which means surprise roaming charges. Off means data only ever uses the eSIM.
  5. Tap Default Voice Line and pick your home plan. (For calls and SMS.)
  6. Tap your home plan → Data Roaming off. Belt and braces — even with cellular data set to the eSIM, this guarantees no accidental home-SIM data abroad.
  7. Tap the esimple plan → Data Roaming on. Travel eSIMs need this enabled to work; the setting allows the SIM to register on networks outside its default home country.

Android setup (Pixel / Samsung / others)

The wording varies, but the structure is the same.

Pixel: Settings → Network & internet → SIMs.

  • Tap the esimple SIM. Toggle Mobile data on. Toggle Roaming on.
  • Tap your home SIM. Toggle Mobile data off. Toggle Roaming off.
  • Back at the SIMs screen, set Calls and SMS to the home SIM.

Samsung: Settings → Connections → SIM card manager.

  • Mobile data dropdown → pick esimple.
  • Calls dropdown → pick home SIM.
  • Text messages dropdown → pick home SIM.
  • Tap your home SIM → make sure Data roaming is off.
  • Tap the esimple SIM → make sure Data roaming is on.

Why "Allow Cellular Data Switching" is dangerous abroad

On iPhone, this is an Apple convenience feature: if the data plan you picked has a weak signal, the phone silently switches to your other SIM to keep you connected. At home this is great. Abroad, "your other SIM" is your home SIM, and switching to it triggers your home carrier's per-MB roaming rate — which can be eye-watering. Turn it off before you fly.

Common gotchas

  • Verification codes not arriving. Make sure your home SIM is set as the SMS line and that roaming on the home SIM is off (calls/texts work without data roaming).
  • iMessage / FaceTime tied to the wrong number. iOS sometimes reassigns these after switching the data plan. Settings → Messages → iMessage off, then on, then pick your home number again.
  • Battery drains faster. Two active radios use more power than one. Carry a power bank.

If something looks off, email support@esimple.ai with a screenshot of your Cellular / SIM settings screen and we'll talk it through.

Dual-SIM setup: keep your home number, use esimple for data · esimple