If you're a new T-Mobile customer or you recently purchased a new phone, you may have a new SIM card you'll need to activate. Here's how to set it up.

Activate a T-Mobile SIM card on your phone. The most common way to activate a T-Mobile SIM card is with your phone itself. It’s easy to do, and you’ll have to follow these steps: ...

T-Mobile subscribers are facing issues with SIM activation due to a widespread outage. Users are unable to make calls, send texts, or connect to the internet after activating a new physical or ...

Purchase a new T-Mobile SIM card. You can purchase a SIM card online at T-Mobile.com, by calling T-Mobile at 800-866-2453 or at any T-Mobile retail store.

T-Mobile and AT&T say US regulators should drop a plan to require unlocking of phones within 60 days of activation, claiming that locking phones to a carrier's network makes it possible to provide ...