
Last month I mentioned how, because my cellphone's 4G LTE bands did not match any of AT&T's and they are turning off 3G early next year, I had chosen to replace it with a Moto G 5G Plus which has rather broader coverage. It turns out that I am also replacing AT&T service with Mint Mobile, who use T-Mobile's network.
The process of transferring my AT&T SIM to the new cellphone started inauspiciously when their website told me to call them and their call-handling system directed me to use their website. However, the fatal nail in the coffin was their computer system. Although my cellphones work just fine, calls are redirected to AT&T customer service until they activate the IMEI for my account. However, their computer simply will not let them do this if the cellphone's model is not on their approved as compatible
list. With my cellphones being European, they are not among the chosen. The attempted transfer left the old cellphone with the same problem.
Mint Mobile do also warn of an incompatible cellphone but, more sensibly, allow me to try anyway, which of course works because the new one covers the relevant 3G and 4G bands well. At least my UK SIM transferred without issue. So, I now have both SIMs working fine on 4G in the new cellphone, having left AT&T behind.