AT&T, the exclusive operator for the iPhone in the US, has had a memo leaked stating customers will only be allowed to buy one of Apple's devices per person in the coming weeks.

It looks likely the stock-control is to keep supplies fresh for the release of the 3G iPhone, tipped to hit shelves at the end of June 2008.

The memo said: "Effective May 14, 2008, customers can only purchase one iPhone at AT&T stores. The prior limit of three iPhones is no longer in effect."

According to the document, requests to buy any more have to be approved by a director or general manager.

There can be only one

Intriguingly, cash or cheque payment is also no longer allowed, though it’s unknown why this block would be put in place, perhaps to allow even tighter stock management.

O2 in the UK has also reported running out of the 8GB version of the iPhone, though still has a number of the 16GB models still in stock and available for purchase.

The company is said to be “reviewing the situation” regarding re-stocking of the 8GB version, but has no plans to change its limit of two per customer, which has been in place since launch.

The memo, leaked to the retail department yesterday, also began new iPhone sales policies, so something will have to shift soon, as customers will become disgruntled with only being able to purchase one phone.

Especially those buying in bulk and apparently selling them overseas to countries where the device is not yet available…