TL;DR: Port-out fraud is when a criminal moves your phone number to their own SIM at another carrier, then uses it to take over your accounts. All three big US carriers have a free lock: Verizon Number Lock, T-Mobile Port Out Protection and AT&T Wireless Account Lock. Turn it on now. Transfer PINs are only needed when you switch carriers, are short-lived, and should never be shared with anyone who calls you.
Why your number needs a lock
Your phone number is the key to most password resets. If a criminal can move it to a SIM they control, they receive your bank codes and "forgot password" texts. That can happen two ways: a SIM swap at your own carrier, or a port-out to a different carrier. Our explainer on SIM swapping covers the first; this guide covers locking down the second.
The FCC adopted rules in November 2023 requiring carriers to use secure methods to authenticate customers before moving a number to a new device or provider, and to notify customers immediately when a SIM change or port-out is requested, The Record reported. The carrier locks below are your own extra layer.
Verizon: Number Lock and Number Transfer PIN
From Verizon's port-out FAQs:
- Number Lock is free. Turn it on by dialling *611 or in My Verizon under the Number Lock section of the Security page. While it's on, your number can't be moved to another line or carrier. It does not stop SIM or device changes.
- Number Transfer PIN is only for switching carriers. Generate it in My Verizon (web or app), or dial #PORT from the phone. It expires after 7 days. Only the account owner or a manager can transfer numbers.
- Verizon says it never asks you for this PIN. Give it only to the new carrier you chose.
T-Mobile: Port Out Protection and Transfer PIN
From T-Mobile's number transfer page:
- Port Out Protection is free for postpaid, business, prepaid and Metro by T-Mobile customers. It blocks unauthorised transfers to another carrier and must be added to each line. On postpaid, only the primary account holder can remove it.
- Temporary Port Out PIN: in the T-Life app, go to Account, the gear icon, Permission & controls, Transfer PIN. Only the primary account holder can create one on postpaid accounts. Port Out Protection must be turned off first.
AT&T: Wireless Account Lock and Transfer PIN
- Wireless Account Lock blocks SIM and eSIM changes, number transfers, device upgrades, new lines and billing changes on postpaid consumer accounts while it's on. In the myAT&T app, go to Services, Mobile Security, Wireless Account Lock, as PhoneArena describes.
- Number Transfer PIN: request one in myAT&T or by dialling *7678 (*PORT). BestPhonePlans reports the six-digit PIN is valid for four days. You'll need to unlock the account before porting.
The scam to watch for
Fraudsters often call pretending to be your carrier ("we're fixing a fault on your line") or a new carrier ("to finish your switch") and ask you to read out a code or transfer PIN. No legitimate caller needs your PIN. Hang up and call the number on your bill. Our guide to why you should never share a one-time code covers the same trick.
Other steps that make port-out fraud harder
- Set a strong account PIN or passcode with your carrier, different from your bank PIN.
- Move important accounts from SMS codes to an authenticator app or passkey; see password managers, MFA and security keys.
- Watch for sudden "No service" on your phone. If it happens with no outage, call your carrier from another phone at once.
- In Australia, carriers must also verify ports; see Scamwatch and ACMA's port-out warning.
Port-out scammers start with your name, number and carrier, often taken from breaches like the AT&T and T-Mobile leaks. Our full scan checks whether your phone number is exposed; start with the free email exposure check.
Frequently Asked Questions
What is a port-out PIN?
A short-lived PIN your current carrier gives you so a new carrier can transfer your number. You only need it when switching carriers.
How do I get a Verizon Number Transfer PIN?
Generate it in My Verizon on the web or app, or dial #PORT from your phone. Verizon says it expires after 7 days.
How do I get an AT&T transfer PIN?
Request it in myAT&T or dial *7678. It is reported to be valid for four days. Unlock Wireless Account Lock first if it is on.
How do I stop someone porting my number?
Turn on your carrier's free lock: Verizon Number Lock, T-Mobile Port Out Protection or AT&T Wireless Account Lock, and never share transfer PINs or codes with callers.
Does Number Lock stop SIM swaps?
Verizon says Number Lock does not stop SIM card or device changes. AT&T Wireless Account Lock does block SIM and eSIM changes while it is on.
Sources
- Verizon: Move your mobile number to another carrier FAQs
- T-Mobile: Transfer your phone number
- PhoneArena: AT&T Wireless Account Lock
- BestPhonePlans: How to get your AT&T transfer PIN
- The Record: FCC adopts new rules to stop SIM swapping