In a move that goes against the grain of US operators introducing tiered or shared data plans, T-Mobile USA has announced the return of an unlimited HSPA+ data plan for its customers after killing off a similar service about 12 months ago.

According to the carrier, the plan is designed to satisfy data-hungry customers and those who do not want to keep track of their data usage. The caveat is that it cannot be used on devices that are tethered or acting as hotspots.

The unlimited HSPA+ plan will be available for $20 per month when added to a Value voice and text plan or $30 per month when added to a Classic voice and text plan.

In July this year, rivals AT&T and Verizon took steps to move away from all-you-can-eat data pricing models, in fear that such business models are low margin or loss making. Instead, they chose to pioneer shared data pricing models that enables families to draw data for each member’s personal device from a single monthly allocation.

However, T-Mobile said in a statement on July 19th that shared data plans are complicated, as individual users don’t know how much of the shared allocation of data they are using, making it difficult to stay within their limit.

“Conversely, at T-Mobile we believe that customers who pay more, should get more,” said Harry Thomas, director of product marketing at T-Mobile USA. He added that data should be worry-free, with no surprise data cap or bill shock, and also flexible and affordable.

“Rather than having to account for each device on a shared family data plan, T-Mobile customers can use their existing data plan to power multiple devices, while still saving hundreds of dollars annually.”

Sprint is the only other US carrier offering unlimited data plans, for which it uses WiMAX technology. However, while Sprint’s network reaches 130 million users, T-Mobile’s HSPA+ network covers 220 million people. Both are currently putting in place LTE networks.