A SIM swap is a scam where fraudsters trick your phone carrier into moving your phone number to a phone they have. Now your phone stops working and their phone acts like yours. But you may not notice for hours or even a few days. In the meantime, the criminals can receive text-message security codes to unlock your accounts.

In its first year being tracked by the FBI, SIM swaps resulted in more than $72 million in losses, according to the 2022 Internet Crime Report.

Here are some steps you can take to avoid these scams:

Think twice before you share online

The more scammers know about you, the easier it is for them to use your personal information to trick the cellphone carrier into switching your SIM to a phone they control.

Protect your phone service account

Use a strong, complex password that is difficult to guess. Do not share it with others. You may also be able to set up a PIN code that the phone carrier requires before making any SIM changes. Check to see what additional protections your phone carrier offers.

Don’t get a false sense of security from text-message codes

Many accounts require two-factor authentication with a code texted to your phone before allowing access to your account. These are exactly the kinds of messages SIM swappers exploit to gain access to your accounts. Multi-factor authentication tools such as Google Authenticator generate one-use codes in an app that can provide protection. Face or fingerprint scans, or a physical device that generates codes, can also keep your accounts safer.

Don’t fall for phishing

If someone calls, texts, or emails looking for personal information, do not share anything. Verify requests that look or sound official via an official channel you find independently, not by replying to the original message.

What about new phones with e-SIMs?

Many new phones use an embedded SIM called an e-SIM rather than a removable one. While an e-SIM shuts off one avenue scammers take—the claim that a physical SIM was damaged or lost—there is nothing about the technology itself that prevents a SIM swap. If criminals can convince the phone carrier to switch your existing e-SIM to a phone in their possession, your accounts are in jeopardy.

If you think you may be the victim of a SIM swap, call your phone carrier immediately. Change your passwords and check all of your accounts for any activity you don’t recognize. Consider freezing your credit file through the credit bureaus. You can sign up for identity theft monitoring services for further protection. The FTC’s website identitytheft.gov offers useful resources in case your information was compromised.