Should I set a SIM PIN on my iPhone?
A SIM PIN locks your SIM or eSIM so it can't make calls or use cellular data until the code is entered. It stops a thief from putting your SIM card in another phone to get your calls and texts, including login codes. Check your carrier's default PIN before you turn it on.
Once it's on, your SIM locks every time you restart your iPhone or remove the SIM card, and you'll see Locked SIM in the status bar until the PIN is entered. Without it, someone holding your SIM card could put it in another phone and start receiving your messages. A SIM PIN doesn't stop a SIM swap, where a scammer talks your carrier into moving your number.
Take care when you first set it up. When you turn it on, your iPhone asks for the current PIN, and if you've never set one, that's a default from your carrier. Don't guess. Apple warns that wrong guesses can lock your SIM. Your carrier may be able to give you a PUK code to unlock it, but if the PUK fails too, you'll need a new SIM.
- Find your carrier's default SIM PIN on its support website or in your plan documents, or ask the carrier
- Go to Settings, Cellular, SIM PIN (on a Dual SIM iPhone, tap the line first), turn it on and enter the default
- Then tap Change PIN to choose your own, and keep it somewhere safe
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