T-Mobile might update their app to offer more painless process eventually, but I couldn't wait. I followed solodogg's awesome instructions to activate eSIM on T-Mobile. I had to make few minor adjustments, but the process is relatively easy. What you need: iPhone XR, iPhone XS, or iPhone XS Max Upgraded to iOS 12.1.1 SIM removal tool from your iPhone packaging or paperclip Connected to Wi-Fi T-Mobile app Launch the Settings app, then General, then About. Hold onto EID field (probably begins with 8904) for few seconds and select Copy. Launch the T-Mobile app, then click on the text chat support icon (upper right corner, next to the phone support icon). When representative welcomes you (wait time was about 10 minutes for me), type "I would like to initiate a SIM swap. My EID is " (hold on to the text chat field then select Paste to fill in the EID number). T-Mobile rep might ask few minor questions like phone model and phone number. T-Mobile rep will eventually initiate the SIM swap, then send a confirmation PIN SMS (takes a minute or two). Type in the confirmation PIN. After few minutes, you will get a confirmation SMS. Thank the rep. Remove the physical SIM card (you do not need to shutdown your phone). Launch the Settings app, then Cellular, Add Cellular Plan, then Enter Details Manually. Enter the SM-DP+ Address: cust-005-v4-prod-atl2.gdsb.net Click Next. If it fails, repeat steps 9 and 10. If asked for Confirmation Code, enter the last 4 digits of your social security number or phone number. You are done. Verify Cellular, P2 page, making sure all the settings are unchanged and Cellular Plans and Usage are same as before. Your eSIM maybe initially assigned with "Secondary" Cellular Plan Label. Change it to "Primary" or whatever you prefer. On the physical SIM slot, I am using a SIM card from the promotional voice line, which will be given to my younger kid eventually.