Sign in to your T-Mobile account on the new phone
Insert the T-Mobile SIM card into the new phone, if needed
If using eSIM, open the T-Mobile app or account and follow the eSIM activation steps
Go to the T-Mobile website or app and select the option to change or activate a device
Choose the line you want to move to the new phone
Enter the new phone’s IMEI or device details if requested
Confirm the change and complete the activation
Restart the new phone after activation
Test calling, texting, and mobile data
If the old phone still has service, power it off or remove the SIM
Contact T-Mobile support if activation does not complete