Apple has begun selling an unlocked version of the iPhone 5 on its Web site, for the first time offering the smartphone without carrier subsidies.

The company had said it would sell a model iPhone 5 that’s not tied to a specific network within a few months of the phone’s September launch. Apple also sells unlocked versions of the iPhone 4S and iPhone 4.

As with other unlocked iPhones from Apple, the device works only with supported GSM networks, meaning that it will not work with Verizon or Sprint. The largest GSM-based network that does not have the iPhone is, of course, T-Mobile.

There have been rumblings that Apple and T-Mobile are bringing the iPhone into the magenta family next month. T-Mobile has said in the past that it wants the iPhone, but that it has to get the timing right. The firm is revving up its 4G LTE expansion right now, but it’s not clear if that will be enough for iPhone 5 customers.

Just last week, T-Mobile USA’s chief operating officer Jim Alling said that the carrier would love to have the iPhone but “we want the economies to be right for us.”

We’ll have to wait and see if the rumor about T-Mobile and the iPhone comes true at next month’s investors meeting. For now, T-Mobile customers will have to stick with the unlocked option.

Without the subsidy, the iPhone 5 starts at $649 for the 16GB model. The 32GB model costs $749, while the 64GB model will set you back $849. Apple limits the sale of the unlocked models to two per customer.