T-Mobile’s UNcarrier model is set to bring a host of sweeping changes to the way T-Mobile does business, of that we’re already beginning to notice. Along with new Value rate plans, T-Mobile is introducing a new trade-in program with two separate options in the hopes of knocking down some of that shock value from Value Plan handset pricing.

So let’s break this down into the two options customers will have with trade-ins in the coming weeks:

1. In-Store: As a customer you will give up the device in-store and receive and instant discount equal to the trade-in value of your old device. You can accept any dollar offer and turn the phone in immediately. As a customer you will also be able to choose between a pre-paid debit card or having the phone value applied to your equipment installment balance credit. The last option for trade-in balances is to use the trade-in balance as a credit toward their monthly statement.

2. Defer: Customers can receive the quoted offer for the value of the device and then take a two-week timeframe to decide their course of action. Customers will have those two weeks to decide if this wish to keep their phone or use it with the trade-in program. Customers can also use the deferred option and ultimately choose to use the trade-in balance as a credit toward their monthly statement.

Customers choosing bill credits will see the credit appear around 2-3 bill cycles after their purchase.

Here’s the answer to the question I’m sure many of you are asking that I can’t answer yet: the phones value will be applied to the EIP (equipment installment balance), of that we’re certain. However, the remaining question is how that dollar credit will apply, will it A) lower your monthly payment or B) instead of paying for 24 months, will the lower balance mean you only have to pay 16 months?

Like a lot of the UNcarrier information, we’re missing some pieces here and there so take everything at face value until we can get a complete picture from T-Mobile herself — whenever they make these new plans public.