Us Brits are pretty hard off when it comes to data plans. Tariffs may not be as expensive as they are in the States, but you can expect to have a pretty tight data allowance when you purchase a smartphone on this side of the pond.

Although most carriers don't allow more than a few GB per month, Three UK has recently launched the One plan, which offers truly unlimited data on all plans which are £35 a month. The plan has proved popular with the iPhone and Android phones, and it seems as though other networks may finally be thinking about following suit.

T-Mobile UK has begun to offer truly unlimited data to its customers who sign up before September 30, presumably to measure the amount of data that these customers will use while they ponder over whether they begin offering it to customers permanently.

t-mobile-uk-unlimited

Phones which are highlighted as having truly unlimited data are the Samsung Galaxy S II, HTC Desire S, and Sony Ericsson Xperia Neo, although any phone which comes with a 24 month plan at £25 per month or higher should come with the same data plan, including other Android phones as well as the iPhone 4.

Unfortunately, tethering isn't included in the bundle so the data offered is strictly for your mobile only. Still, there's no denying that it's a great offer, so if you're in the market for a new phone between now and the end of September, remember to drop by the T-Mobile store and see what they're offering.

Source: T-Mobile (thanks, Anthony!)