How to Lock Your Phone Number So Nobody Can Steal It

Last verified: August 5, 2026

Jump to your carrier: Verizon · AT&T · T-Mobile · Google Fi, Mint, others · What to say if you call · Doing it for a parent

Carrier apps rename their menus regularly. If a step below does not match what you see, the phone script further down works on any carrier.

The short answer

Every major US carrier has a free setting that blocks anyone from moving your phone number to a different device or a different company. Verizon calls it Number Lock and SIM Protection. AT&T calls it Wireless Account Lock. T-Mobile calls it Account Takeover Protection and Port-Out Protection.

It takes about ten minutes. It is off by default. Skip to your carrier below.

First, the confusion nobody clears up

If you search for this, almost everything you find is about the wrong thing.

Search "port-out PIN" and you get page after page explaining how to obtain a code so you can switch carriers. That is a temporary number, generated when you are leaving, and it usually expires within a day.

That is not what you want.

What you want is the opposite: a permanent setting that says nobody moves this number anywhere, including me, until I turn this off myself.

Both things exist. They have similar names. Almost every article covers the first one and skips the second.

Here is the difference in one line:

	What it is	What it does
Port-out PIN / Transfer PIN	Temporary code you request when leaving	Lets you take your number with you
Account lock / Number Lock	Permanent setting you switch on	Stops anyone taking your number at all

You want the second one. This page is about the second one.

Why this matters more than it sounds

There is an attack called a SIM swap. Someone calls your phone company, says they are you, and says they have a new phone. If the representative believes them, your number moves to their device.

They do not need to touch your phone. They need one busy employee at a call center having a bad afternoon.

Once they have your number, every verification code your bank sends arrives on their phone instead of yours. The text message security you have been relying on now works against you.

Your phone number is not just how people reach you. It is the key to your bank, your email, and everything those two can reset. That is why it belongs with the three accounts that matter.

How to Lock Your Phone Number on Verizon

Verizon has two separate settings, and you need both. Most guides mention only one.

Verizon says this plainly in their own documentation: Number Lock does not prevent SIM card changes or equipment changes to your device. Turning on only Number Lock leaves the SIM route wide open.

Setting	What it blocks
Number Lock	Your number being moved to another line or carrier
SIM Protection	Your number being moved to a new SIM or device

Neither is enabled by default. Only Account Owners or Account Managers can turn them on.

Number Lock

Fastest way: dial *611 from your Verizon phone and ask for Number Lock.

In My Verizon:

1. Go to the Security page
2. Find the Number Lock section
3. Select On next to each mobile number you want protected
4. Save Changes

SIM Protection sits directly below Number Lock on that same page.

SIM Protection

In the My Verizon app (postpaid):

1. Sign in to My Verizon
2. Select the Account tab at the bottom of the screen
3. Select Edit Profile and Settings, under your name
4. Scroll to the Security menu
5. Select SIM Protection
6. Toggle On for each number. Green means on, black means off.

Also set an Account PIN while you are in there, if you have not already. Four to six digits, not a birth year.

When you switch these off later, Verizon may hold changes briefly before processing them. That delay is deliberate and exists so a real account holder has time to reverse an unauthorized change.

To port out legitimately, Number Lock must be disabled first, then you generate a Number Transfer PIN. That PIN is temporary and unique to each line.

How to Lock Your Phone Number on AT&T

AT&T launched Wireless Account Lock in July 2025. It is free, and it covers every device and line on your wireless account: smartphones, tablets, watches, hotspots, and laptops.

Note the app name. AT&T now calls it the AT&T app, not myAT&T. Same app, renamed.

Turning it on (postpaid)

Straight from AT&T's own instructions, and it is shorter than most guides suggest:

1. Open the AT&T app. Sign in if asked.
2. Tap the person icon
3. Scroll to and select Wireless account lock
4. Swipe to lock

You have to do this from a device that is active on your wireless account. That is deliberate. It means someone impersonating you on the phone cannot switch it off.

Turning it on (AT&T Prepaid)

Prepaid uses a completely different path, which almost no guide mentions:

1. Sign in to the AT&T app
2. Choose the number you want to lock, then select Continue
3. Select Profile & Settings, then Account Info & Preferences
4. Under Wireless Account Lock, select Turn on
5. AT&T texts a one-time code. Enter it in the PIN Code field and select Validate

What it actually blocks

AT&T lists these specifically:

Device changes

• Device upgrades
• SIM and eSIM swaps and changes
• IMEI changes

Line changes

• Phone number changes
• Transferring a number to or from another carrier

Account and billing changes

• Adding or removing wireless lines
• Changes to authorized users
• Changes to billing info, including account number, billing contact name, address, email, or billing responsibility

What still works while it is locked

This is the part that stops people leaving it off. Locking does not make your account unusable. You can still:

• Make payments, set up payment arrangements, or sign up for AutoPay
• Change plans and add-ons
• Suspend service
• Unlock a device
• Manage NumberSync
• Change your E911 address

If account options look grayed out, that usually means Wireless Account Lock is on. It is working, not broken.

Two things worth knowing

Everyone gets notified. Any time someone turns the lock on or off, AT&T emails the primary account holder and texts every active wireless number on the account. If you get one of those and did not do it, call AT&T immediately.

AT&T can override it in narrow cases. They may temporarily change the lock state to fix an error, to comply with laws such as the Safe Connections Act of 2022, or when an account owner has died.

Who can toggle it: anyone with primary or secondary access to the account. If you have given someone secondary access, they can unlock it.

Standalone tablets, hotspots, and Wireless Home Phones cannot be managed in the app. Call AT&T or visit a store.

AT&T has two passcodes, not one

They do different jobs and you want both set:

Passcode	Used when
Account passcode	You visit a store or call AT&T
Extra security passcode	You sign in to your wireless account online

Set them under Profile, then Sign-in Info. Do not reuse a banking PIN, and write them down offline. Losing them during a real fraud event locks you out of making changes at the worst possible moment.

Remember: unlock before switching phones or changing a SIM, then lock again immediately.

How to Lock Your Phone Number on T-Mobile

T-Mobile calls its strongest protection Account Takeover Protection. It is free and it blocks unauthorized transfer of your lines to another carrier.

One detail most guides miss: it has to be added to each line on your account individually. Turning it on for your own number does nothing for your spouse's line or your parent's line on the same plan.

Turning it on

Online: sign in at T-Mobile.com and go to the Manage Add-ons page. Add Port Out Protection to each line.

By phone: dial 611 from your T-Mobile line and ask the representative to add Account Takeover Protection to every line on the account. This is often faster than hunting through the app, and the app menus move.

Who can do it: only the Primary Account Holder or an Authorized User can add it. Only the Primary Account Holder can remove it. For added security, the Billing Responsible Party must contact T-Mobile to turn it off.

Available to T-Mobile Postpaid, T-Mobile for Business, T-Mobile Prepaid, and Metro by T-Mobile.

Metro by T-Mobile

1. Log in to your Metro account or the myMetro app
2. Select Account
3. Select Account Options
4. Select Account Protection
5. Select Port Out Protection, then On
6. Select Continue

A one-time PIN goes to your device to confirm the change.

Two honest caveats

SIM Change Protection does not cover eSIM transfers on Apple devices. T-Mobile says this is because Apple's own eSIM transfer process already includes extensive security steps. Whether that reassures you is your call, but you should know the gap exists.

Some customers have reported being unable to remove Port Out Protection when they legitimately wanted to switch carriers. If you plan to change providers, allow extra time and contact T-Mobile support before starting the move.

Also set your account PIN or passcode, six to fifteen digits, in the PIN/Passcode section of your account. You will get a text confirming the change.

Google Fi, Mint, and Other Carriers

Google Fi protection is tied to your Google account rather than a separate carrier setting. Turn on 2-Step Verification on the Google account, use an authenticator app rather than SMS, and add a recovery phone that is not the Fi number itself. In the Fi app, check Account settings for transfer protections.

Mint Mobile offers Number Lock, managed in the Mint app or the online portal. Disabling it requires a one-time password sent by text or email.

Xfinity Mobile, Spectrum Mobile, and other cable carriers run on Verizon's network but manage accounts themselves. The protections are usually under account security settings in their own app, and they are often named differently. Call and use the script below.

Consumer Cellular, Boost, Cricket, and other prepaid carriers vary widely. Some offer an account PIN only. Call customer service and ask directly.

A general rule for any carrier not listed: if you cannot find the setting in the app within five minutes, call. The feature frequently exists without being advertised anywhere on the website.

One honest caveat: some users have reported that social engineering attacks still got past carrier protections. These locks raise the difficulty substantially, but they are one layer, not a guarantee. Moving your important codes off SMS entirely is the stronger fix, and it is covered below.

What to Say If You Call Your Carrier Instead

Some people find the apps harder than the phone. That is fine, and it works.

Call your carrier's customer service number from the bill, not from a search engine.

Say this

"I would like to turn on the account protection that prevents my number from being transferred to another device or another carrier. I believe you call it [Number Lock / Wireless Account Lock / Port-Out Protection]. I would also like to make sure no changes can be made to this account without my PIN."

If the representative says they do not have that

"I understand it might have a different name. I am asking for protection against an unauthorized SIM swap or number port-out. Could you check what your term for that is, or transfer me to someone in account security?"

Every major carrier has this. If the first person does not know, ask for a supervisor. That is not rude. It is a training gap, not your problem.

Before you hang up, ask

"Can you confirm that is active now, and tell me exactly what someone would need to provide in order to remove it?"

That last question matters. It tells you how strong the protection actually is.

Write it down

Carrier	______________________
Date	______________________
Features enabled	______________________
PIN set to	______________________
Representative	______________________
Confirmation number	______________________

Store this on paper, somewhere you would keep a passport. Not in your phone.

How to Lock a Parent's Phone Number

This is the most common reason people land on this page, and it is worth doing.

Have them on the line. The carrier needs to hear the account holder authorize the change. Trying to do it as them is both a bad idea and usually unsuccessful.

Tell them beforehand what you are asking for. "I want to add a lock so nobody can steal your phone number" lands very differently from silently changing settings on their account.

Write the PIN somewhere they can find it. A locked account they cannot get into is its own problem, and it will surface at the worst possible moment.

Do it together, once. Not as an ongoing project. Ten minutes, then it is done.

For the wider conversation with a parent, see how to protect parents from scams.

The step most people skip

Locking the number is the right first move. The second move is making the number matter less.

Every verification code sent by text is a code that a stolen number would receive. Move them off text where you can:

• Bank and email first. These are the two that unlock everything else.
• Use an authenticator app rather than SMS. Codes are generated on the device itself, so a stolen number cannot intercept them.
• NIST's own guidelines place SMS in the lowest assurance tier and recommend authenticator apps or hardware keys for anything high value.

Most password managers now generate these codes for you, in the same app that fills your passwords. That is one less thing to manage, which matters more than it sounds when you are setting this up for someone else.

If you want the full walkthrough for moving off SMS, use the two-factor authentication setup guide.

Affiliate disclosure: some links below are affiliate links. If you buy through them, SPG earns a commission at no extra cost to you. It does not change what I recommend.

See password managers with built-in code generation →

How to Tell If Your Number Has Already Been Stolen

The clearest early sign is simple: your phone loses service while everyone around you still has signal. You may see "No SIM" or "SOS Only."

If that happens and you were not expecting it:

1. Use someone else's phone. Call your carrier immediately and ask whether a SIM change or port-out was requested on your line.
2. Then call your bank, using the number on the back of your card.
3. Change your email password from a computer, not the phone.

The FCC requires carriers to notify customers of SIM swap and port transactions, so you may also receive a text or email about a change you did not request. Do not ignore it and do not click anything in it. Call the carrier directly.

If a number was actually taken and accounts were reached, your information is likely circulating and will be reused. Monitoring services watch for your details appearing in new breaches and credit applications. Also see how to tell if you have been hacked.

See what Coveron monitors →

Who does not need this: if you are reading this before anything has happened, do the carrier lock and skip the monitoring. It is free and it prevents more than monitoring does. Monitoring tells you after the fact.

Quick reference

Carrier	Feature names	Where
Verizon	Number Lock and SIM Protection (both needed)	Dial *611, or My Verizon → Security page
AT&T	Wireless Account Lock + two passcodes	AT&T app → person icon → Wireless account lock
T-Mobile	Account Takeover Protection (per line)	T-Mobile.com → Manage Add-ons, or dial 611
Metro	Port Out Protection	myMetro → Account → Account Options → Account Protection
Mint	Number Lock	Mint app or portal
Google Fi	Google account 2-Step Verification	Google account security settings
Xfinity / Spectrum Mobile	Varies, usually account security	Their own app, or call
Prepaid carriers	Often account PIN only	Call and use the script above

Two things nearly all of these share: they are off by default, and they are poorly advertised. Nobody is going to tell you about them.

Frequently asked questions