One caveat for those on T-Mobile, they do not know how to put a second T-Mobile esim in to a phone that already has a TM esim. It can be done. I have two TM lines on my 13 Pro Max but there is a procedure to accomplish this due to the phone only having a single EID. You end up importing the second one from another esim capable device (iPhone Typically) on your account. Other esims from roaming carriers like Airalo & KnowRoaming do not have this issue. They will drop in behind your T-Mobile esim without difficulty.