AT&T is slashing $200 off the price of any iPad when purchasing a new iPhone 5S or iPhone 5C via AT&T Next.

This new promotion is likely a move to get rid of existing iPhone 5S and iPhone 5C inventory ahead of the expected iPhone 6 unveiling next month. Apple is expected to take the wraps off its next-generation iPhone on Sept. 9 and the handset could hit retail by the end of next month. The carrier's deal is available only in select AT&T owned and operated stores, but there are a few catches you should be aware of before taking advantage of this offer.

First of all, interested customers who want a new iPad (any iPad) for $200 off must not only purchase an iPhone 5S or iPhone 5C on AT&T Next, but also agree to a two-year wireless agreement for the tablet. Wireless service is required for both the phone and the tablet, and the carrier further notes that "other charges and restrictions apply."

In other words, in addition to making room for the next-generation iPhone, this promotion may also aim to boost data subscriptions for AT&T. The carrier offers convenient data share plans that make it affordable to add new devices such as an iPad, as adding the tablet to a share plan will cost only an additional $10 per month.

It's also worth pointing out that purchasing a new iPhone 5S or iPhone 4C through AT&T's early upgrade program implies either paying the full price of the device at once, or spread it over 24 months.

As a reminder, the iPhone 5S starts at $650 full price for 16GB, while the iPhone 5C starts at $550 in the same configuration. With 24-month financing and the option to upgrade after 18 months, the iPhone 5S will start at $27.09 and the iPhone 5C at $22.92 per month.

Lastly, the two-year data plan required to get an iPad at this discounted price also means that you would have to choose an iPad with cellular support, which usually costs about $100 more than Wi-Fi-only models.

If you agree to all of these conditions, you would be able to get a 16GB iPad Air, for instance, at $430 instead of the regular $630. For more details, check out AT&T's website.