The clue may well be in the title, but the idea behind it all is that you cough up money for the handset up front, and then you're covered for email and internet access for 12 months.
As for calls and messages, the Pay Once tariff will work the same as pay as you go. The only difference is there's no minimum top-up requirements to keep your free net access, so you only need whack money on it when and if you need to.
You'll get 1GB of data to play with over a month so plenty to get your email, check your Facebook and hop onto GPS whenever you like, and all for £179.99 with a silver Blackberry Pearl 8110 as your handset.
The Pay Once package will be up for grabs from 1 May from T-Mobile stores and online. Let us know what you think to the new tariff below.