T-Mobile phones rely on subscriber identity module (SIM) cards to work. If you need a replacement SIM card, you can get a new one on T-Mobile's website and, in most cases, they will send you a new one for free. Once you receive the card, T-Mobile will activate it for you.
Insert the SIM card into your phone. This typically involves taking the back cover off and removing the battery. The location of the SIM tray or card slot varies depending on the make and model of the mobile phone, so refer to your phone's user guide for detailed instructions.
Call T-Mobile customer services by dialling 0845 412 5000 from your phone. In many instances, the customer services department activates your SIM card without you having to walk into a T-Mobile shop.
Take your phone to a T-Mobile shop if you can't activate the SIM over the phone. Go to the T-Mobile UK website (see Resources) and use the shop locator to find the nearest branch. Shop staff can then activate the SIM card for you.
If you're switching to T-Mobile from another mobile phone network, make sure you get your phone unlocked from the old network before activating the T-Mobile SIM card.
T-Mobile in the UK is now part of the EE network.