How to find out when your current iPhone contract expires
From your iPhone, check the the Apple Store app. On the Web, head to Apple's site.
Apple will start taking preorders Friday for the iPhone 6 and iPhone 6 Plus , and the new models will be in Apple Stores a week later on September 19.
If you are in the middle of your current contract, then you'll pay a pretty penny for the latest iPhone. The entry-level 16GB iPhone 6 Plus costs $299 with a new contract, for example, and a whopping $749 if you are adding it to your current contract.
Thus, the question of when you current contract is up is an important one. Now, you could check with your carrier's Web site to find out the expiration date of your contract, but if you are like me, then you don't remember the password needed to access your account. An easier method is to simply use your iPhone. Or check Apple's site.
To use your iPhone, you will need the free Apple Store app, which is not to be confused with the App Store app. Launch the Apple Store app and from the Featured tab, you will see this featured item:
Tap the Check Eligibility Pricing link and then confirm or enter your phone number, billing ZIP code, and last four digits of your Social Security number. (If for some reason it doesn't call up the right carrier, you can choose an alternate at the bottom of the screen. You can check for AT&T, Sprint, and Verizon.)
With those three fields filled in, tap the Continue button in the upper-right corner and you see pricing information for the iPhone 6 Plus, the iPhone 6, the iPhone 5S, and the iPhone 5C. Because my current contract with Verizon does not expire for over a year, I received two sets of pricing: the sobering numbers should I buy off-contract and the more reasonable prices should I wait until my contract is up.
Also, if you head back to the home screen of the Apple Store app and tap on the Account tab, you can set flip a toggle switch to set up an alert for the day when you reach your contract's blessed expiration date. To do so, however, you may need to go to Settings > Notification Center and enable notifications for the Apple Store app.
If you don't want to install the Apple Store app, then you can go to this page on Apple's site where you can choose your carrier and enter the same three pieces of information as above to see when your contract is up.