I'd like to buy my mother, a T-Mobile customer, an iPhone 15 Plus. I've got a hefty amount of Best Buy gift cards that I was planning to use to pay for the phone, and have it activated on T-Mobile for her in-store.

Much to my dismay, Best Buy and T-Mobile cancelled their partnership the same day the new iPhones were announced. Now, the phone only appears to be sold through AT&T or Verizon activations.

I read online that non-Apple retailers sell Flex Lock iPhones, which are unlocked phones that end up locking to the first carrier the phone is activated on.

I used to be an employee a few years back, and if I remember correctly, scanning any phone's UPC in the point-of-sale system would give you multiple checkbox options, like 'UNACTIVATED UL' or carrier-specific options. If that's true, and the 'Flex Lock' thing is accurate, would it be possible to have an employee sell me an iPhone as an unlocked phone and then I could just personally activate said phone on T-Mobile?

I'm not entirely sure if the phones specifcally come boxed up for AT&T/Verizon or if they're all the same but just end up getting activated on those specific carriers.

Don't want to get anyone in trouble [if this isn't allowed], hence why I'm asking here instead of going in-store immediately. I'd really prefer to buy the phone at Best Buy due to the gift cards, but might ultimately end up just having to buy through Apple themselves. I reckon I'd end up using the gift cards on something eventually, but I've got nothing else in mind so I figured this would be an appropriate time to exhaust them.

Thanks for your time :)

Planning on getting an iPhone 15 Pro from the US cause it's way more expensive back in India. Surfing through BestBuy, Target, Walmart, Costco, Newegg(website CSS doesn't work and is broken for some reason) and Apples own website(Apparently they discontinue the previous years Pro models when the new generation comes out), I couldn't find the unlocked variant anywhere, only used versions. Any suggestions where to find one?