SIM swap fraud: how it works and how to protect yourself
In short
- A SIM swap moves your number to a criminal’s SIM, so your calls, texts and codes go to them.
- The first sign is usually your phone suddenly losing service.
- Add a PIN or password with your network, and move important accounts from text codes to an authenticator app or passkey.
Your phone number can be stolen without touching your phone. If it is, every code texted to it goes to someone else.
How it works
The criminal gathers your personal details, from social media or leaked data, and contacts your mobile network pretending to be you, often saying the phone was lost or broken. The network moves your number to a new SIM in their phone. In a related scam, port-out fraud, they move your number to an account with a different network.
The warning signs
The US Federal Communications Commission says the first sign is usually your phone losing service: no calls, no texts, sometimes only emergency calls.
What to do straight away
- Call your network from another phone, on a number you know is genuine.
- Contact your bank and email provider, and change passwords on important accounts.
- Report it: in the US to the FCC or FTC; elsewhere, to your network and the police fraud reporting service.
How to make it harder
- Ask your network for a PIN or password on your account, and whether it offers a lock on SIM changes and number transfers.
- Use an authenticator app, a security key or passkeys for important accounts; text codes can be redirected. See text codes vs authenticator apps.
- Keep personal details, like your date of birth and address, off social media.
- Hang up on unexpected calls asking for personal details, and call back on a number you trust.
Less exposure
The fewer sites hold your main number, the less there is to leak. For one-off sign-ups, a one-time number from ReserveSMS keeps it private; see keeping your number private.
Common questions
What is SIM swap fraud?
A criminal persuades your mobile network to move your number to their SIM, so your calls, texts and verification codes go to them.
How do I know if my SIM has been swapped?
Usually your phone suddenly loses service. Call your network from another phone straight away.
How can I protect myself from a SIM swap?
Add a PIN or password with your network, keep personal details private, and use an authenticator app or passkeys rather than text codes.