Phone number stolen in a SIM swap

What this means

Your phone number can be stolen without anyone touching your phone. A scammer convinces your mobile carrier to activate your number on their SIM, or transfers it to another carrier.

They now receive your calls and text messages. That includes password-reset and two-factor codes from any account still using SMS.

Treat an unexplained loss of mobile service as urgent when other phones nearby still work. The first target is usually your email, because email can reset almost everything else.

Warning signs

• Your phone shows SOS only, No service, or an inactive SIM for no clear reason.
• Your carrier sends a notice about a new SIM, eSIM, device, or number transfer you did not request.
• Password-reset or sign-in alerts arrive for your email, bank, or social accounts.
• Calls to your number ring on another device or go straight to voicemail.
• Your carrier account password, PIN, or contact details stop working.

Recover now

First 15 minutes

1. Use another phone to call your carrier’s fraud team. Say that your number may have been moved without permission. Ask them to freeze transfers, reverse the SIM change, and put a fraud note on the account.
2. Secure your email from a device you trust. Change its password, sign out other sessions, and remove unknown recovery methods. Do not wait for the phone number to return.
3. Tell your bank that your phone number is compromised. Ask it to block phone and SMS approvals until you regain control.
4. Replace SMS recovery on important accounts. Use a signed-in device, recovery code, passkey, authenticator app, or security key. Start with email, password manager, banking, and payment apps.
5. Save the evidence. Keep carrier messages, account alerts, times, case numbers, and the name of each person you speak to.

Today

1. Ask the carrier exactly when the change happened and whether it was a SIM replacement or a transfer to another carrier.
2. Check email, bank, shopping, payment, and social accounts for password resets, new devices, transfers, purchases, or changed recovery details.
3. Change any password that was reset or exposed. Revoke active sessions before relying on the new password.
4. Report unauthorized payments to the bank immediately. A returned phone number does not reverse money already moved.
5. Once service returns, make one test call and receive one test text. Then ask the carrier to confirm that no other SIM or transfer request remains active.

Verify recovery

• Your carrier confirms that your number is active only on your current SIM or eSIM.
• The carrier account has a new PIN and a transfer or port-out lock where available.
• Your email, bank, and password manager list only your devices and recovery methods.
• Important accounts no longer use SMS as their only second factor.
• No unexplained payment, password reset, or account change remains unresolved.

Prepare now

Lock the phone number

• The carrier account has a unique password and an account PIN that is not your birthday or part of your phone number.
• A SIM-change or port-out lock is enabled if your carrier offers one.
• Carrier alerts reach an email address you check, not only the number being protected.
• The carrier’s fraud number and your account number are saved somewhere other than your phone.

Stop depending on SMS

• Email, banking, and the password manager use a passkey, authenticator app, or security key instead of SMS.
• Recovery codes are printed or stored somewhere the phone cannot access.
• A second trusted device can approve access to your email account.
• You know which important accounts still use your phone number for recovery.

Practice

• You can sign in to your email without receiving a text on this phone.
• You have checked the carrier account and can find its PIN and transfer-lock setting.

Common mistakes

• Waiting for service to return by itself. A real outage affects many people. A SIM swap often affects only you while the attacker is resetting accounts.
• Calling only the normal support queue. Say “fraudulent SIM swap” or “unauthorized number transfer” so the carrier freezes the right actions.
• Changing passwords without revoking sessions. An attacker may already be signed in and will stay signed in.
• Keeping SMS as the recovery method. Getting the number back restores the same weak link that caused the incident.
• Assuming the phone itself was hacked. The carrier account may be the only thing compromised. Resetting the phone wastes time and can destroy useful evidence.

Sources

• FTC: SIM swap scams and how to protect yourself
• FCC: Rules protecting consumers from SIM-swap and port-out fraud