AT&T
Install the myAT&T app on your phone, then enable the Wireless Account Lock.
Verizon
Install the My Verizon app on your phone, or visit the Verizon website. Enable Number Lock and SIM Protection.
T-Mobile
Install the T-Life app on your phone, or visit the T-Mobile website. Enable SIM protection and Port Out Protection.
Google Fi and Mint
Enable Number Lock.
Cricket
Enable Account Lock.
Please reply here if something doesn’t work for you so we can keep this updated. Thank you!