AT&T's buy one get one free deal on the iPhone 8 has a big caveat

You'll have to have a DirecTV or U-Verse subscription.

With the iPhone 8 and 8 Plus models ready for pre-order on Friday, various carriers are letting their respective deals loose. AT&T has a couple of options for its customers. The first, beginning Friday, the carrier will run a buy-one-get-one-free deal on a number of smartphones, including the iPhone 8 and 8 Plus. Of course, that comes with a few caveats. You'll have to get both with the AT&T Next payment plan and you'll have to already have or sign up for DirecTV or U-Verse subscriptions. However, if you only want one of the new phones, AT&T is also offering a 32GB iPad for $100 if you get the phone on AT&T Next.

Sprint's deal also includes a discount on the iPhone 8, but only on the lease. The company is offering 50 percent off of the price of a 18-month lease, bringing the monthly cost to just under $15 per month. But to get the deal, you'll also have to trade in a high-end smartphone like a recent iPhone or Samsung model.

Pre-orders for the iPhone 8 and 8 Plus begin at 3AM Eastern, September 15th.