Reports alleging T-Mobile has shut off Twitter for their customers are rolling in. Complaints have surfaced on T-Mobile’s user forum on Satisfaction as well as several other personal blogs and forums. A T-Mobile representative replied to a customer’s service request with this email:

…Twitter is not an authorized third-party service provider, and therefore you are not able to utilize service from this provide any longer…. T-Mobile is not in violation of any agreement by not providing service to Twitter. T-Mobile regrets any inconvenience, however please note that if you remain under contract and choose to cancel service, you will be responsible for the $200 early termination fee that would be assessed to the account at cancellation.

I’m a T-Mobile customer and testing the issue right now, although I have received sporadic updates as recently as last night. It would be quite astonishing if T-Mobile is blocking an opt-in text messaging service considering how common they are and T-Mobile’s relatively small market share in the U.S. However, it wouldn’t be the first time the company has been at loggerheads with a third party service. Earlier this year, T-Mobile blocked VOIP-based free calling service Truphone, but eventually lost in court.

Update: I have been able to receive messages, but not send them. I have not had the same problem with other short codes. An email is in to T Mobile’s customer support. We’ve also called customer support.

Customer support, at least, says they don’t have a blanket policy against the use of any services on their phones, although they cannot guarantee the operation of any such services. After explaining what Twitter was, T-Mobile tried out the service and pinned the problem on Twitter after receiving a “service temporarily down” message. Biz Stone, however, says T Mobile has blocked them.

Commentors have received sporadic service.