How do I tell if my Apple hardware is covered by AppleCare? My iPhone's lock screen button isn't behaving well and I'd like to take it to the Apple Store to get it replaced. I'm fairly certain I bought AppleCare on it, but the receipt and anything that might indicate I made that purchase are locked away in a storage locker and far from convenient to find.

Is there a way to determine if any piece of Apple hardware is currently under warranty or covered by an AppleCare plan without having the original purchase receipt?
Apple's self-solve web portal can tell you whether any Apple product is currently under warranty or covered by an AppleCare plan. It can also tell you when the coverage ends and help you setup an appointment to get your problem looked in to.

You'll need to know the serial number for your Apple product to look up the coverage. There's an Apple support article on how to find this identifier for all the different bits of hardware Apple makes.