T-Mobile kills the SIM block feature, making employees very happy

T-Mobile is texting customers who had enabled the SIM block feature to let them know that it’s no longer available. This feature was announced to combat SIM swap, a hijacking tactic used by criminals to transfer a customer’s number to a SIM card they own. This allows criminals to view incoming communication, including two-factor authentication (2FA) verification checks and One-Time Password (OTP) sent to verify a user’s identity and grant access to an account or service.

The SIM block feature allowed customers to put blocks at both the line and account levels to prevent their number from being transferred to another SIM card.

T-Mobilehas shored up security since then to fight SIM swaps and a report in April said that self-service SIM swaps may return soon.

While we wait for that to happen, T-Mobile has sunsetted the SIM block feature. Customers will still be protected by the SIM Protection feature, which the company claims offers better security. SIM protection is a free feature designed to prevent unauthorized SIM swaps. Customers can enable and disable it in the T-Life app and on the company’s website. The feature must be toggled off before switching to a new SIM card or moving the eSIM to a new device.

A T-Mobile text telling customers that the SIM block feature has been deprecated. | Image Credit – FullTransparency

Since an alternative to SIM block exists in the form of SIM Protection, no one seems sad to see it go. Employees are happy that the SIM block is being phased out, as sometimes it led to a poor customer experience.

As a rep who has dealt with more than a few accounts requiring a sim change that have sim blocks and no other lines for care to receive one time pins to this is good to hear.  

—sit_n_survive, Reddit user, June 2025

That’s because the blocks were usually enabled and disabled by store staff. When a block was active, accounts were verified using a one-time passcode. Representatives often found themselves in challenging situations when a SIM change was required for accounts with a SIM block and no lines were available to receive the passcode.

Since they released a customer facing Sim blocking customers can control when to block and unblock SIM card changes. Because T-Mobile now has a customer facing some blocking tool the fraud management Sim block is obsolete. It also means that in the instance where a customer just can’t receive a one time pin that blocking can be removed with photo ID verification in store. 

—Ecstatic_Brain_4433, Reddit user, June 2025

The SIM Protection feature gives customers more control and ensures that if they are unable to receive the one-time code for any reason, they can still have the block removed.