eSIM guide

What you are buying

A travel eSIM is a prepaid data plan tied to that digital SIM. Most of them are data only. Your home number stays on the physical SIM, or on the phone's other line, and can still receive texts if you leave that line switched on.

A plan that includes a local phone number is a different product. It can receive local calls and SMS. If the listing does not mention a number, treat it as data only. Messaging apps (WhatsApp, iMessage, LINE, and the rest) work over the data plan either way.

Check the phone before you pay

Two things have to be true. The phone must support eSIM, and it must be unlocked from your home carrier. A locked phone can refuse a plan from another company. Ask the carrier that sold the phone. A shop abroad cannot unlock it for you.

• Dial *#06#. On many iPhones and Android phones the screen lists an EID next to the IMEI. An EID means the phone has eSIM hardware. No EID usually means it does not.
• iPhone: Settings, then Cellular (some regions say Mobile Service), then look for Add eSIM. You can also open Settings, General, About, and look for an EID row.
• Android: the menu name depends on the maker. On Pixels it is often Settings, Network and internet, SIMs. On Samsung phones it is often Settings, Connections, SIM manager. Look for Add eSIM or a SIM manager that mentions eSIM.

Menu names move when the software updates. The EID is the stable check. If Add eSIM is missing and *#06# shows no EID, buy a physical tourist SIM instead.

Install at home, turn it on after you land

1. Buy the plan while you still have wifi. Install it from the provider's app or with the QR code they email. Installation uses the internet. It does not need to happen in the destination country.
2. Read the line that says when the days start. Many travel plans start when the eSIM first connects to a network abroad. Some start on a date you choose, or when you tap install. Leave the new line off until you are ready for the clock to run, if the plan starts on first connection.
3. On arrival, turn the eSIM line on and set it as the mobile-data line. Turn data roaming on for that line only if the provider says the plan needs it. Leave data roaming off on the home line.
4. Keep the home line available for SMS so bank codes still arrive. On a single-SIM phone with no second line, a physical swap removes the home SIM. In that case, bank texts wait until you put it back.

The longer walk-through is Set up an eSIM before you fly.

eSIM or a local SIM

An eSIM bought before the flight gives you data in the arrivals hall, and a dual-SIM phone can keep the home SIM installed. The limits are the phone (eSIM and unlocked), the lack of a local number on most data-only plans, and the difficulty of moving an eSIM to a different handset later.

A local tourist SIM gives you a local number and works in phones that only have a SIM tray. You buy it after you land, so you are offline until the counter finishes, and the shop will register it to your passport where the law requires that. In Thailand that registration is required. The comparison for that trip is eSIM vs a local SIM in Thailand, and the country page is the Thailand guide.