Apple and the carriers say they’ll start taking pre-orders for the iPhone 8 and iPhone 8 Plus on Sept.15 and deliver the new phones starting a week later on Sept. 22. But customers may have to wait days, or even weeks, longer to get their hands on some of the most popular new models and colors if supplies run short, as they often do. And the new premium iPhone X won’t be available to order until Oct. 27 with deliveries starting on Nov. 3.

Without any special deal, such as for people who buy their phones at full price directly from Apple, the new iPhone 8 starts at $699 with 64 GB of storage and the larger screen iPhone 8 Plus starts at $799 also with 64 GB of storage. Apple increased the price of both phones slightly from its similar models in 2016. The iPhone X, when it finally arrives, will start at $999 with 64 GB.

For the best deals on the iPhone X, see this story.

So far, the carriers’ deals are not nearly as rewarding as last year, when most offered a free iPhone 7 with the trade in of another recent model iPhone. Update: On September 18, Sprint started a free-with-trade-in promotion comparable to some of last year’s best deals. For more details, see below.

T-Mobile iPhone Deals

At T-Mobile, the company isn’t offering a direct discount, but it says it will give a credit of up to $300 for iPhone buyers who trade in an iPhone 6 or newer model in good condition for any of the new iPhone models. The credit is paid out over 24 monthly installments.

T-Mobile (TMUS) is also giving three months of free service to customers who put a new cellular-capable Apple Watch Series 3 on their plan. After the free promotion, it’s $10 per month.

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AT&T iPhone Deals

AT&T (T) didn’t announce any trade in offers on Tuesday for new iPhone buyers. But the carrier said it would give a 32 GB iPad to buyers who bought a new iPhone on its “Next” upgrade plan and signed a two-year service contract on both devices. Apple Watch Series 3 buyers will get a credit to cover AT&T’s $25 activation fee and $30 towards service charges. Like T-Mobile, customers pay $10 a month to for wireless connectivity.

Customers who subscribe to AT&T’s DirecTV satellite service or U-verse cable TV service can get a free iPhone if they buy one first and then add an additional line to their account.

Verizon iPhone Deals

Verizon (VZ) like T-Mobile, said it would give up to $300 in credit to iPhone buyers who trade in a recent model smartphone. The offer applies to new or existing customers who sign up for the carrier’s unlimited plan. Verizon also will give Apple (AAPL) watch buyers three months of free service and then charge $10 a month.

Sprint iPhone Deals

Sprint (S) said it would charge half price on a monthly lease for new iPhones if the customer traded in a recent vintage smartphone. Unlike purchase arrangements at other carriers, Sprint’s leases require the customer to turn their iPhone in at the end of the 18 month term or make a lump sum payment (customers can also upgrade their phone after 12 months). Sprint also said it was making separate “personalized” offers to some customers. And the carrier offered the same deal for Apple watches, with a $10 monthly fee after three free months.

Update: On September 18, Sprint improved its offer. Customers on Sprint’s 18 month Flex leasing plan who turn in a most recent vintage smartphone, like an iPhone 7 or Samsung Galaxy S8, get a free iPhone 8 entry level model via monthly billing credits on a new line. Trade ins of other models, such as an iPhone 6S or Moto Z Play, still qualify for half off the new iPhone. The remaining balance would be due if a customer canceled service or switched to another carrier before the term of the lease was up.

(This story was updated on Sept. 13 with Sprint’s offers and again on Sept. 18 with Sprint’s revised offer.)