First it was pay as you go, with people topping up an amount and fearing that text telling them that they would soon be unable to text. Then came the contracts, offering you the ability to pay a monthly fee in order to get a set amount of minutes and texts before being charged additional amounts. The third stage to this evolution was phone subsidies, similar to contracts but at a greater cost, these contracts came with a mobile phone offering you the chance to get the latest phone at a slightly higher cost but with monthly payments. An alternative to this third method was to pay a small fraction upfront for your device while you had a contract. Seems like AT&T is just one of many looking to stop this process.
By paying a fraction of the price upfront, you could walk away with a brand new model on a contract, however if you wished to leave the contract or upgrade to a new model and keep the original handset you were expected to pay for the remainder of the phone.
With companies like T-mobile and Verizon Wireless already stopping the up-front payment method AT&T customers will either have to bring their own phone, pay full price upfront or pay monthly for the device in a separate device payment plan.