T-Mobile US Inc (NYSE:TMUS) has managed to strike a deal with Apple Inc. (NASDAQ:AAPL) for its 7-day Test Drive program. And Apple has agreed to supply ‘tens of thousands’ of iPhone 5S units to the telecom carrier for free. John Legere, chief executive of the Bellevue-based company said at the company’s Un-Carrier 5.0 event Wednesday that the company will give potential customers a free iPhone 5S with unlimited data just to “test drive” its network for 7 days.

How will the deal benefit Apple?

Legere outlined that ‘7-night stand’ program in an interview with Re/Code. He said customers can sign up online using this link starting June 23. They will get to use the phone for a full week and then they can return it to any T-Mobile US Inc (NYSE:TMUS) store. The company estimates that more than one million will sign up for the program in the first year of its availability. When Apple Inc. (NASDAQ:AAPL) lunches a new iPhone, T-Mobile will upgrade the offer to the latest model.

Allowing people to try out its network for free could win T-Mobile US Inc (NYSE:TMUS) some new customers in the fiercely competitive telecom market. What’s surprising is that Apple Inc. (NASDAQ:AAPL) has agreed to supply over a million iPhone 5S units free of charge. But the program could be a boon for the iPhone maker as the iPhone 5S is late in its life cycle as the iPhone 6 is expected to be released in September.

Test Drive packaging much worse than Apple’s own white boxes

The Verge got an opportunity to pick up a sample Test Drive iPhone 5S unit after the Un-Carrier 5.0 event. The packaging (below) isn’t as attractive as Apple Inc. (NASDAQ:AAPL)’s own carefully designed white boxes. The Verge noted that it feels closer to what you get when you buy a refurbished iPhone.

Apple T-mobile

A cautious note. The sign-up process requires a credit card, and you can test drive only once a year. To prevent potential customers from pocketing the iPhone 5S, T-Mobile US Inc (NYSE:TMUS) places a $699.99 hold on your credit card. If you return the device with water damage or a cracked screen, you’ll have to pay $100. If you don’t return the phone at all, you’ll be charged $699.99. And if you return it in its original condition, you pay nothing.

Apple Inc. (NASDAQ:AAPL) shares were down 0.15% to $92.04 at 9:51 AM EDT on Thursday.