iPhone 13 pro max with trade in
I want to purchase a 13 Pro Max, but would like to trade in 2 phones - A 11 Pro Max and 8 Plus. I dont see anyway to trade in more than one phone. Also, my service is AT&T, but I do NOT like their trade in program forcing me to change my phone plan. If I order a phone non branded from you, it it unlocked and does it come with a SIM card or do I remove from my old phone and use in new phone.
iPhone 11 Pro Max, iOS 14