Days after T-Mobile introduced its Jump plan for upgrading smartphones, AT&T is jumping into the fray with an installment plan to let customers upgrade their devices annually. Starting July 26, AT&T Next will let customers buy a new smartphone or tablet once per year with no down payment. Customers can trade in their phones after 12 months or pay for 20 months and then keep the device.

The plan is structured a little differently than T-Mobile's Jump

The plan is structured a little differently than T-Mobile's Jump, which runs $10 monthly; with AT&T Next, you're only paying the cost of the device itself spread out over a number of months, running $15 to $50 per month. A Samsung Galaxy 4 on AT&T Next would cost $32 a month in addition to the cost of the customer's voice and data plan, for example. If you cancel your wireless plan while you're on the installment plan, AT&T will bill you for the remaining balance on the device. But the offer applies to AT&T's entire lineup, and could make regular upgrades more affordable for customers who can't afford to pay hundreds of dollars up front for a new device.

Whether it makes sense to try Next depends on how often you upgrade, how much cash you typically have on hand, and how good you feel about a rolling commitment to AT&T. It's worth noting that AT&T used to let all of its customers upgrade after 12 months with a new two-year agreement, no installment plan required. For a subset of AT&T customers, the Next program could make upgrading a bit easier in the short term — even as it makes the cost of phone ownership more expensive over the long term.

Update: The post originally stated that subscribers would pay two payments, one for their current device and another for their next, assuming the first device is traded in before the monthly payments on it are complete. This is not correct — payments on the first device cease when it is traded in. The post has been updated to reflect that.