It appears that T-Mobile was very well prepped up for the launch of new iPhones on September 12, as the carrier has publicly announced trade-in deals for Apple's latest smartphone lineup. As pr T-Mobile, all the customers, who trade an iPhone 6 or newer in good condition iPhone in exchange for an iPhone 8, iPhone 8 Plus, or the iPhone X, will receive a $300 credit.

For the consumers, who are interested in buying the most expensive iPhone ever, iPhone X, a $300 credit will definitely help in dealing with the big burning hole in your pocket or...may be not. The iPhone X costs a whopping $999 for the 64GB variant and $1,150 for the 256GB model.

The carrier has also announced that Apple is offering three months of free cellular service on the new LTE-equipped Apple Watch Series 3, which the company launched on September 12 at the same event as iPhone 8, iPhone 8 Plus and iPhone X launch.

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After the promotional period ends, T-Mobile says you can carry on getting unlimited talk-time, text, and data balance for just an extra $10 a month. You will be able to add the Apple Watch to your plan via T-Mobile's Digits service, which is the same service that allows you to migrate your phone number to other internet-connected devices, like watches or a work phone, or share it with friends and family members.

However, this deal will be available to only those T-Mobile customers who purchase a new iPhone on an equipment installment plan, or EIP. An EIP financing plan is intertwined with T-Mobile's Jump program, which is the company's hardware upgrade program similar to that of AT&T Next and Apple's iPhone Upgrade Program. Most devices purchased on EIP Plan are eligible for Jump upgrades after the customer is done paying 50% of the original device's cost.

You can jump right onto the deal and grab a new iPhone but make sure that you understand all the nitty-gritties of your T-Mobile plan.