SIM swap
In a SIM swap, a fraudster gets your phone number moved to their own SIM card and receives your SMS verification codes.
Signs
Your phone suddenly loses signal, unexpected SIM change notices, password reset emails you did not request.
Protection
Use an authenticator app, passkey or hardware key instead of SMS, set a carrier PIN and remove your number as a recovery option where possible.
Frequently asked questions
I think I was SIM swapped. First step?
Call your carrier to recover the line, then change passwords and verification methods on key accounts.