SIM Twinning / Cloning / Duplicate for "Light Phone"

I would start with facebook chat as that was the most helpful.  I had to contact T-mobile 10 times and go to three different stores (I’m not exaggerating).  They don’t do this very often and will try to gaslight you into thinking your asking for something else or will just tell you it can’t be done but keep trying, maybe you’ll get lucky and have this resolved quicker than I did.

All that said, here is what they need to do:

1. Establish a “data with paired digits line”.  They can either set up a new digits line for you or convert an existing digits line you have.
2. Once it’s set up, they need to pair the new “data with paired digits line” to your main line.  Once this is done you will receive a text confirmation that your data with paired digits line has been paired with your main line.
3. You’ll need a physical sim card for your data with paired digits line to put in your 2nd phone.  The data with paired digits line will have a temporary sim assigned to it once it’s set up.  You can either ask the rep that’s helping you to assign it to a physical sim and ship that sim to you or you can go in store and ask them to give you a sim card for the data with paired digits line.

You’ll likely need to pay $25 for the physical sim and you’ll definitely need to pay $10 per month for the data with paired digits line.

Your second phone will be able to make and receive calls and texts like your main line and have slow (but useable) data.  It actually works better than I expected with the exception of sms short codes.  Your data with paired digits line cannot receive them so you can’t use it for 2fa etc.