SIM cards

The SIM card is the brain of your digital phone and gives you access to our advanced nationwide 4G network. Don't confuse it with an SD card, which is an extra storage memory device you can insert into a phone that stores data, such as pictures and videos.



How SIM cards work

The SIM card number is linked to your personal phone number, so you can call, text, browse the web, and more from just about anywhere. You can usually transfer the SIM card from your current phone into another phone to keep your personalized service information.


  • Retail T-Mobile phones come with a SIM card in the box.
  • To replace your SIM card, you can buy a SIM starter kit.
  • If you need specific steps for your device to help with inserting a SIM card into your phone, you'll find guides and steps on the Phones and Devices page.


SIM card sizes

Different phones use different kinds of SIM cards. To find out what kind of SIM card your phone is designed for, view the Tech Specs for your phone. Find them by clicking your phone on the Phones and Devices page. There are three sizes the T-Mobile SIM Card currently supports:


  • Nano SIM: The smallest SIM size and most likely to be found in new devices.
  • Micro SIM: A medium sized SIM card. Not normally found in new devices, but popular in previous models.
  • Standard SIM: The largest SIM size, sometimes called Mini SIM. Found in much older devices.


SIM Card.jpg


Embedded SIM (eSIM)

Some devices have the SIM card built inside and the card cannot be removed. When returning a device with an embedded SIM, you may need to switch your mobile number to a new device or cancel the line of service. If neither action is taken T-Mobile may cancel the associated line after 14 days and deactivate the returned embedded SIM card.


SIM security features

You can lock your SIM card to help prevent someone from using your phone by securing it with a PIN number. If you forget your PIN, the PUK code on the back of your SIM jacket can be used to unlock it as well.


SIM card



Switch your SIM to a new phone

Switching phones is now a lot easier, thanks to your SIM card. You can quickly and easily switch out your SIM card to another phone that uses the same type of SIM, without having to worry about losing the benefits of the T-Mobile network.