To combat SIM swap attacks of impersonation and deception tactics, known as social engineering attacks, three major phone carriers in the United States — AT&T, T-Mobile, and Verizon — have introduced security features that make it more difficult for malicious hackers to deceptively get a customer’s account changed, such as porting out their phone number. In July, AT&T introduced its free Wireless Account Lock security feature to help prevent SIM swaps. The feature allows AT&T customers to add extra account protection by toggling on a setting that prevents anyone from moving a SIM card or phone number to another device or account. The feature can be switched on via AT&T’s app or through its online account portal by anyone who manages the account, so make sure that account is protected with a unique password and multi-factor authentication. T-Mobile allows customers to prevent SIM swaps and block unauthorized number port outs for free through their T-Mobile online account. The primary account holder will have to log in to change to the setting, such as switching it on or off. Verizon has two security features called SIM Protection and Number Lock, which prevent SIM swaps and phone number transfers, respectively. Both of these features can be turned on via the Verizon app and through the online account portal by an account’s owner or manager. Verizon says that switching off the feature may result in a 15-minute delay before any transactions can be performed — another safeguard to allow the legitimate account holder to reverse any account changes.