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eSIM explained: what it is and how to switch

Plain-language guide. Details vary by phone and carrier, so confirm before you switch.

An eSIM is a SIM card built into your phone as software. Instead of a plastic card you push into a tray, your carrier sends a profile to the phone, usually by QR code or through the carrier's app.

Why people use one

• Switch carriers without waiting for a card in the mail.
• Keep two lines on one phone, such as personal and work, or home and travel.
• There is no card to lose, and a thief cannot simply pop it out.

Check before you switch

• Does your exact phone model support eSIM? Recent iPhones sold in the US have no physical SIM tray at all, so eSIM is the only option there. Many Android phones support both a card and an eSIM.
• Is the phone carrier-unlocked? A locked phone only accepts profiles from the carrier that locked it.
• Does the new carrier offer eSIM on the plan you want? Not every carrier or plan does.

How switching usually goes

1. Confirm the phone is unlocked and supports eSIM.
2. Sign up with the new carrier and choose eSIM.
3. With the phone on Wi-Fi, scan the QR code or follow the carrier app's activation steps.
4. If you are keeping your number, let the new carrier handle the transfer. Do not cancel the old line first.
5. Test calls, texts, and mobile data before you remove the old service.

Traveling

Many travelers add a data eSIM from a local or travel provider and keep their home line for calls and texts. Check your home plan's roaming charges first, and turn data roaming off on the home line if you are using a separate data eSIM.

Things that go wrong

• Deleting an eSIM profile can mean you have to ask the carrier for a new one. Do not delete one unless you are sure.
• Some carriers verify your identity before moving a number. Have your account details ready, and keep them out of chat tools.