How Do I Activate My T Mobile Sim Card. Put your new SIM into your device and switch it on if you need help find out how to insert a SIM. Enter the required information.
Then simply enter your existing mobile number in the appropriate box along with the new 19 digit ICCID number. Turn mobile phone on. This can take up to 90 seconds.
Use this key to activate the SIM card online.
Log in to your account on the T-Mobile website. If your SIM card is inactive you can reactivate it by following these steps. You simply choose the size you need snap it out from the perforated edges and insert it into the SIM card tray of your phone. Choose if youre activating a physical SIM or eSIM.
