Aio has three plans to choose from, and they all include unlimited talk, text, and data. The service costs $40 to $70 a month, depending on the plan. New subscribers can get a free month of service if they sign up before September 29.
The announcement comes less than a week after smaller rival T-Mobile filed a lawsuit in federal court accusing Aio Wireless of trademark infringement over its use of the color magenta -- a shade of which happens to look a little too similar to its own traditional branding, according to T-Mobile.
T-Mobile accelerated its own no-contract strategy following its acquisition of MetroPCS, and AT&T appears eager to follow suit. Prepaid plans, which at one time appealed to lower-income consumers, now are drawing a wider swath of customers who are interested in more affordable options.