What it is
SIM swapping is a fraud where the attacker convinces the mobile carrier to move your number to a SIM or eSIM they control. They then receive your calls and SMS, including the codes to access bank, email and social accounts.
How it works
- 1The attacker gathers your personal data through phishing, data breaches or social networks.
- 2They contact the carrier posing as you, or trick an employee, and get your number transferred.
- 3Your phone loses the line while theirs receives your SMS.
- 4With the codes they receive, they reset passwords and access your accounts and bank.
How to spot it
- Your phone suddenly loses signal for no reason
- SMS or emails from the carrier about a SIM change you did not request
- Password reset notifications or sign-ins you do not recognise
- You can no longer make or receive calls
How to defend
- Do not use SMS as your only second factor: prefer authenticator apps, passkeys or security keys
- Set a PIN or security passphrase on your line with the carrier
- Do not publish unnecessary personal data (date of birth, tax ID, number)
- Turn on push notifications in your bank’s app
- Protect the email tied to your accounts with special care
If you think you have been hit
- Contact the carrier at once from another phone and get your SIM reactivated
- Tell your bank and block cards and access
- Change the passwords, starting with email, and sign out active sessions
- Report to the police
And there are many, many more
The attacks above are only some of the most common: there are hundreds, and new ones appear every week. If the one that concerns you is not among them, write to me: I will tell you whether it really affects you and how to defend.
Contact meOther attacks
Watch the Shorts on YouTubeMatteo Russo · Updated October 2026