How to Lock Your Phone Number Against SIM-Swap and Transfer Fraud

For SIM swap protection, turn on your carrier’s free lock (Verizon’s Number Lock and SIM Protection, T-Mobile’s Port Out Protection and SIM Protection, AT&T’s Wireless Account Lock, or the versions at Cricket, Google Fi and Visible), which stops anyone from moving your number to another carrier or a new SIM until you turn it off. Just remember to switch it off before a real transfer.

Below is what each lock is called, what it blocks and where to find it, checked against each carrier’s own help pages in October 2026.

SIM swap and port-out fraud: two ways criminals steal a number

• SIM swap. A criminal gets your number moved to a SIM card or eSIM they control, often by pretending to be you. Verizon says your calls and texts, including one-time security codes, then go to them.
• Transfer (port-out) fraud. A criminal starts a transfer that moves your number to another carrier. The FCC says a successful port-out moves the victim’s number to a device the scammer controls.

Either way, your phone suddenly stops working, and Verizon notes that some victims only find out then. Carriers fight back with two kinds of locks: one blocks transfers to another carrier, the other blocks SIM changes. Some carriers use one switch for both.

Quick summary by carrier

Carrier	Lock	What it blocks	Where to turn it on
Verizon	Number Lock	Transfers to another carrier	My Verizon, Security
Verizon	SIM Protection	SIM changes and device upgrades	My Verizon, Security
T-Mobile	Port Out Protection	Transfers to another carrier	Plan add-ons, line by line
T-Mobile	SIM Protection	SIM and eSIM changes	Profile, Security
AT&T	Wireless Account Lock	Transfers, SIM and eSIM swaps, many account changes	AT&T app
Cricket	Account Lock	SIM swaps and transfers	myCricket app
Google Fi	Number Lock	Moving the number to another phone or carrier	Fi website only
Visible	Line Lock	Transfers and new SIMs or eSIMs	Visible app or website

Verizon: Number Lock and SIM Protection

Verizon says Number Lock doesn’t stop SIM card or device changes, so turn on both. Only the Account Owner or an Account Manager can change either one.

Number Lock

1. In the My Verizon app, open the Account tab and tap Edit Profile and Settings.
2. Scroll to the Security Menu and tap Number Lock.
3. Switch on the numbers you want to protect and save.

On the website, go to Account, then Account Settings, then Security Settings, and choose Edit next to Number Lock. You’ll get a text confirming it’s on. To turn it off, follow the same steps; Verizon may send a security code to confirm. Prepaid customers have to wait 15 minutes after turning it off before they can create a Number Transfer PIN.

SIM Protection

In the app: Account tab, then Edit Profile and Settings, then Security Menu, then SIM Protection, and switch on each line. A protected line is blocked from SIM swaps, device upgrades and bring-your-own-device changes. Prepaid customers find it under Account, then Account Settings, then the Security tab.

Two things to know: store and customer service staff can’t turn it off for you, and after you turn it off there’s a 15-minute wait before a SIM change can go through. See Verizon’s SIM swapping page for every path.

T-Mobile: Port Out Protection and SIM Protection

SIM Protection

T-Mobile calls it a free feature for all postpaid customers. In the T-Life app, open the Manage tab, tap the gear icon, then Security, then SIM Protection. Switch it on and tap Save Changes. Prepaid customers sign in at T-Mobile.com with the primary line and go to My T-Mobile, then My Profile, then SIM Protection.

Port Out Protection

Free for postpaid, business, prepaid and Metro by T-Mobile customers. It has to be added to each line separately:

1. In T-Life, open the Manage tab and tap See Plans.
2. Tap Manage add-ons and choose the line.
3. Check Port Out Protection, tap Continue, then Agree & Submit. Repeat for each line.

On postpaid accounts, authorized users can add either feature, but only the Primary Account Holder can remove them. The steps for the website and prepaid accounts are on T-Mobile’s SIM Protection and Port Out Protection page.

AT&T: Wireless Account Lock

One switch covers almost everything: device upgrades, SIM and eSIM swaps, number changes, transfers to or from another carrier, adding or removing lines and billing changes. You can still pay your bill, change your plan and suspend service while it’s on.

1. Open the AT&T app on a device that’s active on your AT&T wireless account, and sign in if asked.
2. Tap the person icon.
3. Scroll to Wireless account lock and tap it.
4. Swipe to lock. To turn it off later, tap Unlock the account.

Users with primary or secondary access can change it, and AT&T sends an email and texts whenever anyone does. AT&T Prepaid customers find it in the app under Profile & Settings, then Account Info & Preferences. Details are on AT&T’s Wireless Account Lock page.

Cricket, Google Fi, Visible and other carriers

• Cricket: Account Lock. In the myCricket app, go to Settings, then Security, and switch on Account Lock. It blocks SIM swaps and transfers on every line. To turn it off, tap Continue and enter the one-time PIN Cricket sends.
• Google Fi: Number Lock. Web only: sign in to Fi on the web, open Privacy & security under Phone settings, choose Sign in to manage Number lock and switch it on. If you lose access to your Google Account while it’s on, Google says Fi can’t give you your transfer details, so add a recovery email.
• Visible: Line Lock. In the app or on the website, open Device details for your line, expand Line Lock & portout-PIN and tap Lock. When you unlock it, you can choose “Until I lock it again” or a date range, and it takes 30 minutes to take effect.
• Xfinity Mobile has a number lock too. Its help page says to make sure it’s off on any line you’re transferring, but doesn’t give the steps, so ask Xfinity.

For any other carrier, search its help pages for “number lock,” “port out protection” or “account lock,” or ask customer service what it offers.

Two more layers worth adding

A SIM PIN

A SIM PIN protects the SIM card in your phone, so a thief can’t pop it into another phone. On an iPhone, go to Settings > Cellular > SIM PIN (it works for eSIMs too). On a Google Pixel Fold, Verizon’s device guide lists Settings > Security & privacy > More security & privacy > SIM lock. Other Android phones vary, so check your phone maker’s or carrier’s guide.

Be careful: Apple warns never to guess the PIN. If you’ve never set one, use your carrier’s default. A wrong guess can lock the SIM. Your carrier may be able to give you an unlock code (PUK); if not, you’ll need a new SIM or eSIM.

Logins that don’t depend on texts

The FTC says text-message codes are better than nothing, but an authenticator app is safer because it isn’t exposed to a SIM swap, and a security key is the strongest option. Switch your email and bank logins over where you can.

And never read your transfer PIN or account PIN to someone who calls you. Verizon and Cricket both say they’ll never ask for your PIN that way.

Turn the lock off before a real transfer

A lock can’t tell a scammer from you. If you’re switching carriers, do it in this order:

1. Turn off the lock at your current carrier, both the transfer lock and, if you’re changing phones, the SIM lock. The account owner may have to do it.
2. Wait if your carrier requires it: 15 minutes for Verizon prepaid before you can create a transfer PIN, or 30 minutes for Visible.
3. Get your account number and transfer PIN. Our guide to finding your transfer PIN and account number covers each carrier.
4. Give them to your new carrier, which starts the transfer.
5. Turn on your new carrier’s lock once the transfer is complete.

Forgot step 1? A lock that’s still on will block the transfer. See number transfer stuck or rejected for the fix.

Signs your number was taken, and what to do

• Your phone suddenly loses service for no clear reason.
• You get a text about a new SIM, a new device or a transfer PIN you didn’t request.

Contact your carrier right away. Verizon customers can dial *611 (Verizon says it works even on a deactivated phone) or call 1-800-922-0204 from any phone; Cricket’s number is 1-800-274-2538. Then, as Verizon advises, change the passwords on your email and financial accounts, check your email’s security page for logins you don’t recognize, and review your credit report.

Frequently Asked Questions

Is there a charge for a number lock?
Not at the carriers in this guide. Verizon, T-Mobile, AT&T, Cricket and Google Fi all describe their locks as free, and Visible lists no charge.

What’s the difference between a number lock and SIM protection?
A number lock (or port-out protection) stops your number from moving to another carrier. SIM protection stops it from moving to a new SIM or eSIM at the same carrier. Verizon and T-Mobile offer them separately. AT&T, Cricket, Google Fi and Visible cover both with one setting.

Will a number lock stop me from upgrading my phone?
A SIM lock can. Verizon says SIM Protection must be off for a device upgrade, and Cricket says Account Lock must be off for upgrades and SIM swaps. Turn it back on afterward.

Does a SIM PIN replace a carrier lock?
No. A SIM PIN protects the physical SIM or eSIM on your phone. A carrier lock protects your number at the carrier, where SIM swaps and transfers actually happen. Use both.

I’m switching carriers. When should I turn the lock off?
Right before you request your transfer PIN, since some carriers won’t issue one while the lock is on. Turn on your new carrier’s lock once the transfer is complete.

Getting a new number? Lock it once it arrives

If you buy a number from 212areacode.com, you transfer it to your own carrier. The account number and transfer PIN your new carrier asks for appear in My Numbers in your 212areacode.com account, usually the same or next business day. We never send them by email. The transfer takes 3–5 business days to a mobile carrier such as T-Mobile, Verizon, AT&T or Cricket, and your new carrier sets the date. Once the number is working on your phone, turn on that carrier’s lock. You can browse available numbers here.