QUICK ANSWER To activate a T-Mobile SIM card, insert it into your phone while it is powered off. Turn on your phone and follow the prompts on your screen to log into your T-Mobile account. You may ...

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.

A new report shares that T-Mobile customers will be able to change SIM cards on their own starting April 24. Customers will be able to make this change via the T-Life app. New features in the T ...