T-Mobile is opening up access to its Starlink-powered emergency texting service. The carrier announced on Wednesday that anyone with a compatible phone — even AT&T and Verizon customers — can sign up to text 911 over satellite for free.

You can sign up for emergency satellite texting if you have a phone compatible with T-Satellite, though there are some pretty notable exceptions. It doesn’t support phones with emergency satellite texting built in, including the iPhone 14 and later, as well as the Pixel 9 and up (excluding the 9A). That means you can only use T-Mobile’s 911 texting if you have an iPhone 13, Pixel 9A, a Samsung Galaxy S21 and up, or a newer Motorola phone.

If you’re a non-T-Mobile customer, you’ll also need to have an unlocked phone with an eSIM.

T-Mobile customers can sign up for the emergency satellite texting service by signing into their T-Mobile account online and choosing the option under the “Manage Data & Add-ons” section. Everyone else can enroll by signing up through T-Mobile’s website. Once you’re signed up, T-Mobile notes that your phone will automatically connect to T-Mobile’s emergency texting network in areas without cellular coverage.