T-Mobile has officially discontinued its SIM block feature, a security measure introduced in 2022 to prevent SIM swap attacks.
These attacks allow criminals to hijack phone numbers by transferring them to new SIM cards, potentially compromising accounts through intercepted two-factor authentication codes and one-time passwords.
Customers who had enabled SIM block are being notified via text messages that the feature is no longer available. The company has replaced it with SIM Protection, a free tool designed to offer improved security and greater user control.
Unlike SIM block, SIM Protection can be enabled or disabled by customers through the T-Mobile app or website. It must be turned off before switching SIM cards or transferring eSIMs to new devices.
T-Mobile employees have welcomed the change because the old SIM block sometimes complicated customer service, especially when users needed SIM changes but lacked other lines to receive verification codes.
With SIM Protection, customers can manage their SIM security directly, and in-store verification via photo ID can help remove blocks if needed.
The move aims to enhance security while improving customer experience, especially as T-Mobile considers bringing back self-service SIM swaps in the future.
