Someone on another forum just explained to me that with ATT, you have to obtain a plan/service, that includes 5G, i.e. pay ATT more a month!
And, with that, you get a new white SIM card.
Ugh! Is all I can say to that...
I went through this with Verizon. Some sales person in the store told me I needed to change my service plan if I wanted to upgrade from my iPhone X to an iPhone 12. She tried to tell me I could only upgrade to an iPhone 11.
I have a great plan now, and the new 5g plan they wanted to ‘upgrade’ me to would have cost an additional $40/month for a couple of phones, iPads and an AW6). To make matters worse, I’m in upstate NY where 5g won’t be built out for a couple of years, so I’d be paying for nothing.
After searching this forum, I ultimately ordered an iPhone 12 Pro directly from Apple. Initially, I pulled the SIM card from my old iPhone X and installed it in my new phone. This got me up and running, but I got error messages telling me to is it my provider and get a 5g SIM card. I went to Verizon and was given a new 5g SIM card at no charge. I think Verizon did charge me $20 to switch the phones on my account. This didn’t change my plan.
I won’t bother paying for 5g until is available in my market.