How to check & verify iPhone warranty.
1. Open up “Settings” on your iPhone.
2. Tap on “General”
3. Tap on “About”.
4. You will see your iPhone Serial Number.
5. Go to page https://selfsolve.apple.com/GetWarranty.do. Enter hardware serial number, select your location and click on Continue.
6. On this page, click on the “See your service and support coverage”
7. You will be brought to a page where you will see your detailed warranty status.