Your Phone Number Could Be the Key to Your Bank Account. Here's How to Protect It.

Imagine receiving an unexpected message saying your phone has lost service.

You try making a call, but it doesn't work. Your texts aren't coming through either.

Meanwhile, a criminal has persuaded your wireless carrier to transfer your number to a device they control.

They can now receive calls and text messages intended for you, including some security codes used to access online accounts.

If they also have your login information, they may be able to get into your email, financial accounts, or other services.

SIM swapping doesn't automatically give someone access to all your accounts. They may still need passwords or other information. But losing control of your phone number can remove an important layer of protection.

AT&T, T-Mobile, Verizon, and Google Fi all offer security features designed to make unauthorized transfers more difficult.

Some features prevent someone from moving your number to another SIM or device. Others prevent your number from being transferred to another wireless carrier.

These are two different threats, so it's important to understand which protections your carrier provides.

Here's how to enable them.

Wireless Account Lock

AT&T offers a free feature called Wireless Account Lock.

When enabled, it blocks certain account changes, including SIM and eSIM swaps, phone-number changes, and transfers to or from another wireless carrier.

The lock applies to all eligible devices and lines on your wireless account.

How to enable it:

1. Open the AT&T app on a device connected to your wireless account.
2. Sign in if necessary.
3. Tap the person icon.
4. Scroll down and select Wireless account lock.
5. Swipe to enable the lock.

AT&T sends an email to the primary account holder and a text message to each active wireless number when the lock is turned on or off.

T-Mobile offers two separate protections worth enabling.

1. SIM Protection

This helps prevent someone from moving your number to another SIM or eSIM.

To enable it:

1. Open the T-Life app.
2. Select Manage.
3. Select the gear icon.
4. Choose Security.
5. Select SIM Protection.
6. Enable protection for your entire account or individual lines.
7. Save your changes.

2. Port Out Protection

This helps prevent someone from transferring your phone number to another wireless carrier.

To enable it:

1. Open the T-Life app.
2. Select Manage.
3. Under My Account, select See Plans.
4. Select Manage add-ons.
5. Choose the line you want to protect.
6. Find Port Out Protection under the available services.
7. Select it and complete the confirmation process.

Important: Port Out Protection must be added separately to each line you want protected. Don't assume protecting one number protects the others.

Both features are available at no additional cost.

Verizon also offers two separate protections.

1. SIM Protection

This helps prevent unauthorized SIM changes, including SIM swaps and certain device upgrades.

To enable it:

1. Open the My Verizon app.
2. Select Account.
3. Go to Edit Profile and Settings.
4. Scroll to the Security section.
5. Select SIM Protection.
6. Choose the phone number or numbers you want to protect.
7. Turn protection on.

2. Number Lock

This helps prevent someone from transferring your phone number to another wireless carrier.

To enable it:

1. Sign in to My Verizon.
2. Go to Account.
3. Select Account settings.
4. Select Security settings.
5. Find Number Lock.
6. Select the number you want to protect.
7. Turn the feature on and save your changes.

Both features are available without an additional charge.

Important: Verizon's Number Lock and SIM Protection are separate features. Enable both for more complete protection.

If you use Google Fi, there's a feature called Number Lock.

It's free and provides an additional layer of protection against unauthorized SIM swaps and number transfers.

When Number Lock is enabled, you cannot:

• Transfer your number to another phone.
• Transfer your number to another wireless carrier.

How to enable it:

1. Visit https://fi.google.com/account.
2. Sign in to your Google Account.
3. Under Phone settings, select Privacy & security.
4. Find Number Lock.
5. Select Sign in to manage Number Lock.
6. Re-enter your account credentials.
7. Turn Number Lock on.

Google Fi also ties your wireless service to your Google Account, so securing that account is particularly important.

Google recommends enabling two-step verification and adding a recovery email.

Important: If you lose access to your Google Account while Number Lock is enabled, Google Fi cannot provide your port-out information. Make sure your account recovery options are current.

Smaller carriers may offer similar protections, but the names and procedures vary.

Examples include:

• U.S. Mobile
• Mint Mobile
• Visible
• Cricket Wireless
• Spectrum Mobile

Look for features called SIM Protection, Account Lock, Number Lock, or Port Out Protection.

If you can't find them, contact your carrier and ask two specific questions:

1. Can I prevent someone from transferring my number to another SIM or eSIM?
2. Can I lock my number against unauthorized transfers to another carrier?

Don't assume that a general account PIN provides both protections.

Carrier protections can make SIM swapping more difficult, but they don't eliminate the risk.

Another important step is to reduce your reliance on SMS-based two-factor authentication.

Whenever possible, consider these alternatives:

Passkeys: These allow you to sign in using your device's built-in security, such as a fingerprint, facial recognition, or device PIN. They are designed to resist phishing.

Authenticator apps: These generate security codes independently of your phone number. Examples include Proton Authenticator, Google Authenticator, and Microsoft Authenticator.

Physical security keys: These provide another strong option for protecting particularly important accounts.

For accounts that offer these alternatives, they're generally preferable to receiving security codes by text.

An unexpected loss of cellular service could have several explanations, including a network outage or technical problem.

But if it happens without explanation, don't simply assume it's a temporary glitch.

Contact your wireless carrier immediately using another phone or a trusted internet connection.

Ask whether someone has requested a SIM change or number transfer on your account.

If you discover an unauthorized transfer:

• Ask your carrier to restore control of your number.
• Change your important account passwords, starting with email.
• Check bank and credit card accounts for unauthorized activity.
• Contact financial institutions if you suspect your accounts have been accessed.
• Report identity theft if appropriate.