If you get phones from the manufacturer they’re not labeled compatible with AT&T so much as that they have access to specific radio ranges and are controlled either by soft-stored codes or by a SIM card, and I’d buy the sim card from the service, and then stick it in my phone. The Sony I had for a while was compatible with both the T-Mobile and AT&T ranges, and I used a third party service that was an el-cheapo front for T-Mobile.
T-Mobile wanted me to pay extra for hot-spot use, but I got around that with software, which is like hacking the subscription seat warmers on your BMW.
Curiously, Apple phones will lock themselves (or did for a while… is it better now?) based on what service you initially connected them to, and you have to (had to, I hope) get their permission and pay fees to unlock it again.
The telecommunication companies are an oligopoly, so like a legal cartel, so they pull a lot of bullshit that we end users have to suffer. But it means I feel not a jot of guilt when I hack the hell out of it to extract services I didn’t pay for, since it’s all a grift anyway.
Chris_Saturn@lemmy.world 3 weeks ago
A lot of the big tech stores here in the US have separate counters for each of the major mobile carriers, and sell devices that are locked into those contracts. You can sometimes get unlocked phones from big tech stores, but most of what they carry is locked to a carrier.