If your phone has not been dropped, water damaged or opened by somebody else, Apple will service your phone at no costs.
Warranty service for eligible repairs is available at no charge for twelve months from the date of purchase. After you return the iPhone that needs service, Apple will examine the iPhone to confirm that the failure is covered by Apple warranty.
Apple's Limited Warranty for iPhone excludes coverage for damage resulting from accident, disassembly, unauthorized service and unauthorized modifications. Please review the warranty for further details.
An iPhone that is ineligible for warranty service may be eligible for Out-of-Warranty (OOW) Service. For example, an iPhone that has failed due to damage or liquid damage is ineligible for warranty service but eligible for OOW service. However, certain damage is ineligible for OOW service, including catastrophic damage, such as the device separating into multiple pieces, and inoperability caused by unauthorized modifications. Please see Apple's Repair Terms And Conditions for further details. Refer to this article to check if the Liquid Contact indicator on your product has been triggered.
If your iPhone is not eligible for warranty service, you may wish to contact your carrier for other options.
If defects arise as a result of service, Apple will cover the repair for the remaining term of the iPhone's warranty or 90 days after iPhone service, whichever provides longer coverage for you.
copied from Service Answer Center - iPhone /Philippines