In recent years, SIM swapping attacks have increased, prompting the mobile industry to try to combat them more effectively.
SIM swapping is a type of fraud in which a scammer transfers your mobile phone number to a SIM in their own device. By intercepting calls or texts sent to your phone, they can capture two-factor authentication codes and other information intended for you. From there, the attacker can take over not only your mobile account but also other accounts that rely on authentication.
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SIM swapping attacks can play out in a couple of different ways. A scammer may be able to convince the mobile carrier to transfer the SIM to a new device by pretending to be you. Criminals have also offered money to employees at such carriers as Verizon and T-Mobile, tempting them to perform SIM swaps.
The three major US carriers — AT&T, T-Mobile, and Verizon — all offer their own tools to protect your account from SIM swapping scams. I subscribe to Verizon on my main iPhone and T-Mobile and AT&T on my test and backup phones, so I’ve used these security settings for all three. Here’s how to protect yourself from these types of attacks across all three carriers.
1. Verizon Wireless
Verizon offers two safeguards against SIM swapping attacks. SIM Protection prevents unauthorized SIM or device changes on your phone number unless you disable the setting. Number Lock blocks any unauthorized swaps of your mobile phone number. I’ve turned on both and would advise all Verizon subscribers to do the same.
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SIM swapping attacksTo set these up, sign in to your account at the Verizon website or through the My Verizon app for iOS or Android.
SIM Protection
If you’re using the website, select Account at the top of the screen. On the Account page, click Account overview. Next, select Profile and settings. Under the Security section on the left, click the link for SIM Protection. Turn on SIM Protection for each line in your plan, and then click the Save Changes button.
If you’re going through the My Verizon app, go to the Me screen and tap Profile and settings at the top. Swipe down to the Security section and tap SIM Protection. Turn on the setting for all your lines.
Number Lock
To turn on Number Lock on the website or in the My Verizon app, go back to the previous screen after enabling SIM Protection. In the Security section, select the link for Number Lock. Turn on Number Lock for the lines you wish to lock. On the website, be sure to click Save Changes.
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Verizon offers other security settings worth investigating. You can set up and use a passkey instead of a password. The secret question option lets you choose a question and answer to help Verizon reps confirm your identity if you call to request a change. The Voice ID feature analyzes your speaking voice to verify your identity when you call.
2. T-Mobile
T-Mobile’s SIM Protection aims to thwart unauthorized number transfers. To enable this, sign in to your account at the My T-Mobile website. Click the My T-Mobile button at the upper left and select My Profile. On your profile page, select SIM Protection. Turn on the switch for your number and any other lines you wish to protect. Check the box for “I agree to these conditions,” and then click Save Changes.
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3. AT&T
AT&T offers a setting called Wireless Account Lock, which prevents unauthorized account changes, billing updates, and wireless number transfers.
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To set this up, you’ll have to install and use the AT&T app for iOS or Android. Fire up the app and make sure you’re signed in to your account. Tap the person icon at the upper right. Swipe down the screen and tap the setting for Wireless Account Lock. To confirm your action, swipe across your phone in the highlighted area. A message notifies you that your account has been locked.
If you ever need to disable the account lock to modify your account or phone number, return to the same screen and tap the Unlock Account button.
