Accounts
Keep your phone number yours.
In a SIM swap, someone talks your carrier into moving your number to their SIM. From then on your calls and texts go to them, including the codes banks and email providers send to reset a password. A lock at your carrier stops it.
Locks by carrier
Under FCC rules, US carriers must let you lock your account against SIM changes and number transfers for free.
| Carrier | Turn on | What it blocks | Where |
|---|---|---|---|
| AT&T | Wireless Account Lock | SIM swaps, number transfers, device upgrades and other account changes, until you turn it off. | myAT&T app. Turning it off needs the app on your phone, so a caller can’t talk an agent into it. |
| Verizon | SIM ProtectionNumber Lock | SIM Protection stops your number moving to another SIM or eSIM. Number Lock stops it being transferred to another carrier. | My Verizon app: Account, Edit profile & settings, Security. Turn on both, for every line. |
| T-Mobile and Metro | SIM ProtectionPort Out Protection | SIM Protection blocks SIM changes. Port Out Protection blocks transfers to another carrier, and only the primary account holder can remove it. | T-Life app or t-mobile.com: Profile, Security, SIM Protection. Port Out Protection is in each line’s settings. |
| Google Fi | Number lock | Moving your number to a new phone or another carrier, including requests made through customer support. | fi.google.com/account: Phone settings, Privacy & security, Number lock. Web only, not in the app. |
| Mint Mobile | Number Lock | Activating a new SIM, ordering a replacement and changing phones. | Mint app or website: Account, Security, Number Lock. Verify your email first, since turning it off sends a code there or to your number. |
| Cricket | Account Lock | SIM changes, including upgrades, and transfers to another carrier. | myCricket app. On a single-line account, turning it off means calling Cricket. |
Whoever your carrier is, ask them to put a PIN on your account and to require it for SIM changes and transfers.
| Carrier | Turn on | What it blocks | Where |
|---|---|---|---|
| Rogers, Fido and chatr | Port request text | Transfers to another carrier: you get a text and must reply YES within 90 minutes, or the transfer doesn’t go ahead. | On by default. Ask Rogers by phone to add an account PIN as well. |
ACMA rules make every carrier check more than your personal details before moving your number to another carrier (since 2020) or a new SIM (since 2022).
| Carrier | Turn on | What it blocks | Where |
|---|---|---|---|
| Telstra | Telstra PINApp verification | Account changes, SIM swaps and transfers made without your PIN, fingerprint or face check. | My Telstra app: set up two-step verification with a Telstra PIN or biometrics. |
UK networks don’t offer an opt-in lock. To switch, you request a PAC or STAC code, normally by text from the phone itself, so moving your number usually needs your SIM first. EE, for one, sends a code to your current SIM before swapping it. Set a strong account password or PIN with your network, and keep your SIM PIN on.
Checked October 2026. Carriers move these settings around; if a step doesn’t match, search your carrier’s app for “lock” or “SIM”. Not listed? Ask yours for a port-out PIN or number lock by name.
Whatever your carrier
A lock only helps if the rest of your accounts don’t depend on your number.
- 1
Set an account PIN or passcode with your carrier that isn’t your birthday, card PIN or the last digits of your number. Store it in your password manager.
- 2
Turn on every lock your carrier offers, for every line on the account, including family members’ phones.
- 3
Move logins off SMS codes, starting with email, banking and crypto. A passkey, security key or authenticator app can’t be redirected by a SIM swap. Check what each site supports.
- 4
Where a site lets you, remove your phone number as a way to recover the account, or at least make sure it isn’t the only one.
- 5
Keep your number off public profiles. A leaked number is the starting point; see which breaches included phone numbers.
Signs it’s happening
Your phone loses service for no reason.
It shows “No service” or “SOS only” while phones around you work fine. Your number is now active on another SIM.
Messages about changes you didn’t make.
A text or email about a new SIM, eSIM, device, transfer PIN or port request.
Password resets you didn’t ask for.
Emails saying your password changed, or that someone signed in from a new device.
If it’s happening now
Minutes count. The attacker is working through your accounts while you do this.
- 1
Call your carrier from another phone or over Wi-Fi. Say your number was taken in a SIM swap, ask them to move it back and lock it, and get a reference number.
- 2
From a device you trust, change your email password and sign out all other sessions. Email resets everything else, so it comes first.
- 3
Call your bank and any crypto exchange on the number from their website or your card. Ask them to freeze outgoing transfers.
- 4
Once you have the number back, change passwords and 2FA on everything that used it, and check for forwarding rules or recovery addresses the attacker added.
- 5
Report it to the police for a crime reference, which banks often ask for. In the US, also report it at IdentityTheft.gov. Then go through what leaked.