With activation of a JUMP! On Demand lease plan, T-Mobile offers the Apple iPhone 6s 16GB Smartphone for T-Mobile for $0 up front plus $5 per month for 18 months when you trade in an Apple iPhone 6, Samsung Galaxy S6, or Samsung Galaxy Note 5. Alternatively, you can get it for $10 per month for 18 months when you trade in an Apple iPhone 5s, Samsung Galaxy S5, or Samsung Galaxy Note 4 or $15 per month for 18 months when you trade in most other smartphones. (The Apple iPhone 6s Plus 16GB Smartphone is also available for $9, $14, or $19 per month for 18 months via the same trade-ins, respectively.) That's $560 below the cost of buying the iPhone 6s outright from T-Mobile, although you won't own this phone after your lease is up. (It's also a savings of $397 over the 18 months versus a monthly installment plan for buying outright.)

You can also get the iPhone 6s 64GB Smartphone for $99.99 down plus $4, $9, or $14 per month for 18 months via the trade-ins above, respectively, or the 128GB version for $199.99 down plus $3, $8, or $13 per month for 18 months . (The iPhone 6s Plus versions are available for the same plus an additional $4 per month.) The latest iPhone is due for release on September 25.

Note: It's unclear if this offer will be available in stores only or online. (T-Mobile's website doesn't yet feature the offer on product pages; however, if you have preordered the phone, which you can currently do online, T-Mobile will apply the same offer via an upfront bill credit.) The offer is subject to credit approval, and additional fees, including activation and insurance, may apply. At the end of the 18 months, you can choose to purchase the phone at a discounted rate.