I ran into an interesting issue attempting to purchase AppleCare for a set of headphones I picked up at Best Buy. I was within the sixty day window but when I tried making the purchase online I was presented an ominous message:
“It looks like your device isn’t eligible for an AppleCare agreement.”
The AppleCare rep was stumped. After a bit of googling I discovered the headphones didn’t have a purchase date associated with them—presumably because they came from a third party retailer.
The fix is to visit https://checkcoverage.apple.com, enter your details, and you’ll more than likely be prompted to provide a purchase date. I was then able to complete my purchase.