SIM swapping is when a criminal tricks a mobile carrier into moving your phone number to a SIM card they control, so they can intercept calls and text messages, including security codes. It is often used to break into bank, email, crypto, and social media accounts.

Quick Scoop

A SIM swap attack usually starts with the attacker gathering personal details, then impersonating the victim with the carrier. Once the number is transferred, the victim may suddenly lose service while the attacker receives one-time passcodes and password reset links.

Why it matters

  • It can bypass SMS-based two-factor authentication.
  • It can lead to account takeover, money theft, and identity abuse.
  • It remains an active threat, with recent reporting noting new carrier protections and ongoing attacks.

Common warning signs

  • Your phone suddenly loses signal or service.
  • You stop receiving calls or texts.
  • You get password reset or login alerts you did not request.

How to reduce risk

  • Use an authenticator app or hardware security key instead of SMS codes.
  • Ask your carrier for extra account protection, such as a SIM swap or port-out lock.
  • Strengthen account recovery settings and avoid exposing personal details publicly.

If your number has already been swapped, contact your carrier immediately and secure your email and financial accounts first.

TL;DR: SIM swapping is a phone-number hijacking scam that can let criminals steal your accounts by intercepting text-message verification codes.