Scam Advice (Fraudulent SIM Swap)

Fraudulent SIM Swap

A fraudster tricks or bribes your mobile operator into moving your phone number onto a SIM they control, then uses it to intercept calls and one-time codes and take over your accounts.

How the scam works

Scammers rely on urgency and trust. They create time pressure so you act before verifying, and they impersonate a sender you’d normally trust without a second thought.

• Your phone suddenly loses signal or shows “no service” with no explanation
• You stop receiving calls or texts you were expecting
• You get an SMS confirming a SIM or number change you didn’t request
• Account alerts arrive for logins or password resets you didn’t initiate

How to protect yourself

• Add a PIN or passcode to your mobile account that’s required for any SIM change
• Avoid using SMS as your only two-factor method — use an authenticator app where possible
• Be cautious what personal details you share publicly (DOB, address) — these are used to pass identity checks
• Ask your bank whether it checks for recent SIM changes before approving risky transactions (the GSMA SIM Swap API supports this)

If you think you’ve been targeted

1. Contact your mobile operator immediately to freeze the line and reverse the swap
2. Contact your bank to freeze accounts and reverse any unauthorised transactions
3. Change passwords on accounts linked to that phone number, starting with email
4. Enable non-SMS multi-factor authentication once you regain control
5. Report the incident to your national fraud reporting body

National fraud reporting bodies

Mobile network operators