T-Mobile wants you to buy an iPhone 6s for $20 a month

T-Mobile is using the release of the new iPhones to lure you into switching carriers. And it might work.

T-Mobile is using the release of the new iPhones to lure you into switching carriers. And it might work.

Following the announcement of the iPhone 6s and the iPhone 6s Plus, T-Mobile has announced that for a limited time you will be able to get these brand-new devices for $125 cheaper. T-Mobile is offering both new iPhones through its Jump On Demand 18-month installment program. The 16GB iPhone 6s costs $20 a month, while the 16GB iPhone 6s Plus goes for $24 a month, with no down payment required.

With T-Mobile Jump, you can trade-in your phone for a new model anytime, up to three times a year. After the 18 months, you can pay off $164 and keep your iPhone. That makes the price of buying a 16GB iPhone 6s through T-Mobile's Jump plan $524, as compared to the full $649 retail price.

Apple has also jumped on the installment plan bandwagon. During Wednesday's event, the company announced its first-ever iPhone Upgrade program. Get an unlocked 16GB iPhone 6s to use with any carrier for a monthly cost of $32.41, which you'll pay to Apple directly. The iPhone Upgrade plan includes AppleCare+, the two-year phone support and warranty that has to be typically paid in full for $129. As with other installment plans, you can trade in your phone at any point after 12 months.

The story behind the story: Carriers continue to opt for offering installment plans over two-year contracts. In addition to T-Mobile's Jump On Demand program, Sprint offers the "iPhone Forever" lease program, AT&T has the Next installment plan, and Verizon has gotten rid of contracts for all new customers.

As carriers start competing not only with each other but with Apple itself to sell new iPhones, both phone prices and wireless service are bound to get cheaper.