SIM swapping: when someone steals your phone number

How it works

A scammer gathers some personal details about you, often from data breaches and social media. Then they contact your mobile carrier pretending to be you and ask to move your number to a new SIM card, or to transfer it to another carrier. Sometimes they bribe or trick a store employee.

Once the number moves, your phone loses service. The scammer receives your calls and text messages, including the codes that many services send to confirm a sign-in or reset a password. They can use those codes to get into email, banking and other accounts.

Warning signs

• Your phone suddenly shows no service or “SOS only” somewhere it normally works.
• You get a message from your carrier about a SIM change or number transfer you did not request.
• You get password reset emails you did not ask for.

How to protect yourself

• Add a PIN or passcode to your mobile account. Most carriers offer extra protection against SIM changes and number transfers. Ask for it.
• Use an authenticator app or security key instead of text message codes for important accounts, especially email.
• Keep personal details off public profiles, such as your birthday and phone number.
• Act fast if your service drops unexpectedly. Call your carrier from another phone, then change passwords on your email first.