AT&T expands unlimited plan to all customers, single line pricing starts at $100

Both consumers and business customers can take advantage of the new plan pricing, which includes unlimited talk, text and data on four lines for $180 a month. Business customers can get an even better deal with corporate discounts.

Prior to the change, users looking to sign up for unlimited data were required to also hold a DirecTV or U-Verse account.

AT&T confirmed details of the new unlimited tier to AppleInsider, saying single-line plans cost $100 with each additional line coming in at $40. Though a four-line example is being used to advertise the plan, customers can add additional unlimited users to their account as needed.

As noted in today's press release, the fourth line is essentially free via a monthly bill credit that starts after two billing cycles. Customers will have to pay $220 per month until the credit kicks in.

The usual trimmings are also included in the plan, allowing users to make unlimited calls from the U.S. to Canada and Mexico and send unlimited texts to over 120 countries. Customers who opt in to the free Roam North America feature can take advantage of unlimited talk, text and data in Canada and Mexico with no roaming charges.

"We're offering unlimited entertainment on the nation's best data network where and when you want to enjoy more of what you love," said David Christopher, Chief Marketing Officer of the AT&T Entertainment Group.

According to the fine print, AT&T retains the right to throttle data speeds after 22GB of data usage, though the company claims slowdowns should occur only during periods of network congestion.

AT&T's new plan arrives just days after Verizon announced the resurrection of its own unlimited data tier. T-Mobile, which offers all-you-can-eat data under the One plan, responded to Verizon by activating HD video and adding a 10GB high-speed Mobile Hotspot feature at no extra charge.

With AT&T opening its unlimited tier to all comers, users in the market for uncapped data can now select a plan from all four major U.S. carriers. Those thinking about upgrading can check out AppleInsider's head-to-head comparison to see which offering best suits their needs.