The FCC announced new rules to protect consumers against illegal SIM swaps last year. Major US carriers have already adopted SIM protection features in line with these rules, and it’s now Google Fi‘s turn to offer this functionality.

Google Fi quietly announced a Number Lock feature (h/t: 9to5Google) to protect users against illegal SIM swaps. Enabling this feature means that you can’t transfer your phone number to another phone or port your number to a new network.

To enable Number Lock, you’ll need to sign into your Google Fi account, tap Privacy and security > Sign in to manage Number lock. You’ll then need to sign into your account again and toggle the Number Lock switch. We’d definitely advise you to enable this as soon as possible.

Number Lock: A handy solution to SIM swap fraud

Illegal SIM swaps see cyber-criminals posing as you to steal your phone number by transferring it to a SIM they control. This lets criminals access your two-factor codes if they’re still sent via text message, leaving the door open for your banking accounts and other sensitive services to be compromised.

Many services have moved away from text-based two-factor authentication in favor of email, authenticator apps, and other, more secure solutions. But illegal SIM swaps are still a nightmare to deal with due to the inconvenience alone, so we’re glad to see Google implement Number Lock functionality.

The move also comes after Verizon introduced its own Number Lock functionality to protect against SIM swaps. Meanwhile, T-Mobile introduced a so-called Account Change Engine back in April, which is used to determine the legitimacy of SIM change requests.