SIM swap protection: lock your number with a PIN and carrier lock
How to stop SIM swap fraud: turn on a SIM PIN, the free carrier lock from AT&T, Verizon or T-Mobile, and what FCC rules now require from US carriers.
Your phone number is a master key: it receives bank codes, resets email and social passwords and verifies WhatsApp. In a SIM swap, a criminal talks your carrier into moving your line to their SIM or eSIM, or ports the number to another carrier. From then on, your verification texts go to them.
How common is SIM swap fraud?
The FBI IC3 2024 report logged 982 SIM swap complaints and $25.98 million in losses, down from 2,026 complaints and $72.65 million in 2022. Often the only warning sign is your phone suddenly losing service, as TechCrunch notes.
What do FCC rules require from carriers?
Under the FCC rule adopted in November 2023, wireless carriers must use secure authentication before a SIM change or port-out, notify customers immediately of SIM change requests, and offer a free account lock that blocks SIM changes and ports. Easily found details such as your address or recent payments do not count as secure authentication.
| Carrier | Free feature | Where to turn it on |
|---|---|---|
| AT&T | Wireless Account Lock | myAT&T app or online account |
| Verizon | SIM Protection and Number Lock | App or portal, by the account owner |
| T-Mobile | SIM swap and port-out blocking | Online account, primary holder |
AT&T's lock, launched in July 2025, also blocks device upgrades, new lines and billing changes, and can only be turned off in the app from a device on the account, according to MacRumors.
How do I set a SIM PIN?
On iPhone, Apple lists Settings > Cellular > SIM PIN. Use your carrier's default PIN to set a new one, and never guess: too many wrong tries require a PUK code and can permanently lock the SIM. A SIM PIN protects the card in a stolen phone; the carrier lock is what stops an impostor from getting a new SIM.
Is an SMS code still a safe second factor?
It beats nothing, but it is exactly the link a SIM swap exploits. Wherever your bank, email or social accounts allow it, switch from text-message codes to a passkey, an authenticator app or a hardware key, and keep the phone number only as a last-resort recovery option. Also set a separate PIN for WhatsApp two-step verification, so a hijacked number alone cannot take over your chats. Under the FCC rule, carriers must also give victims an easy way to report fraud, investigate it promptly and provide documentation at no cost, which helps when you dispute bank transfers made after the swap (Federal Register).
What to do
- Turn on the carrier lock and a SIM PIN today.
- Protect your carrier account with a unique password and MFA.
- Replace SMS codes with passkeys or an authenticator app where possible (passkeys and MFA guide).
- Lost service for no reason? Call your carrier and bank from another phone right away.
- Victim? Report at IC3, ask your carrier for fraud documentation (required free of charge under FCC rules) and reset passwords from a clean device.
In Brazil, number porting has required SMS confirmation since August 2023 (DPL News). More in SIM swap, protection tips and the scam radar.
来源
- FBI IC3 2024 Internet Crime Report
- FCC: Protecting Consumers From SIM-Swap and Port-Out Fraud (Federal Register, 2023)
- Apple Support: Use a SIM PIN for your iPhone or iPad
- TechCrunch: How to protect your cell phone number from SIM swap attacks
- MacRumors: AT&T launches Account Lock
- DPL News: novas regras de portabilidade numérica
- Teletime: Câmara aprova PL sobre identificação de chamadas e validação de chips
- Mobile Time: Anatel, Origem Verificada e biometria em linhas