It appears that T-Mobile isn't particularly keen to sell the new iPhone 5 when it comes out in September, at least not in the US.
According to a leaked memo, T-Mobile is telling employees that they should start "selling against the iPhone" on September 21, thought to be the date that Apple will start shipping the new iPhone 5.
In the US T-Mobile doesn't officially carry the iPhone, and this memo would suggest that isn't about to change. In the UK T-Mobile does offer iPhones, however.
T-Mobile and Orange have joined up under the banner of Everything Everywhere in the UK, and following recent approval by Ofcom, may be able to offer 4G in the UK as soon as September, meaning that they may be the only UK operator to offer a 4G version of the iPhone 5 if it launches in September as predicted.
TmoNews has the original memo to T-Mobile employees here.