Unlimited data is back.

AT&T has followed Verizon Wireless back the era of unlimited data plans, starting tomorrow.

The AT&T Unlimited plan will be available to all customers, not just those signed up with DirecTV, and will be expensive. A single line unlimited voice, text, and data plan will reportedly cost $100 a month. Customers switching four lines to unlimited data will pay $180 after a $40 bill credit kicks in 60 days after signing up. This means for the first two months, customers will pay $220 for the privilege of unlimited data.

The new plan is open to residential and business/corporate accounts and business customers will also get the benefit of any corporate discounts.

AT&T’s definition of “unlimited” actually means 22GB. If you exceed that amount, AT&T reserves the right to slow your data connection “during periods of network congestion.”

The plan includes:

• unlimited calls from the U.S. to Canada and Mexico
• unlimited texts to over 120 countries
• talk, text and use data in Canada and Mexico with no roaming charges when adding the free Roam North America feature
• the ability to switch off AT&T’s “Stream Saver” which limits online video playback to 480p

“We’re always listening to our customers and will continue to evolve to provide more choice, more convenience, and more value,” claims AT&T in a press release. But observers believe AT&T listens to the competitive realities of the marketplace more than its customers who never wanted to lose the option of unlimited data in the first place.