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Having finally purchased AC+ for my iPad Air 3, I can now confirm that it covers 2 years from the purchase of the coverage, not the device... sort of.

That is to say, even though I purchased the coverage today (the 20th), for some reason it ends on Dec 18th, 2021. Not sure why it's 2 days short of the full two years. (shrug)
 
That's good that it worked out for you. Mine was date of activation of the Mini 5 minus the 14 day return policy with the carrier (it was a leased device, but I paid it off completely). shrugs.
 
Also interesting is that I thought that some sort or remote diagnostic of the device would be done before the policy was applied, but no.
So given these facts, there’s no reason to buy AC+ until the last minute. You’ll be covered for up to 60 days longer, and don’t have to worry about being ineligible if something does happen to your device in the meantime, because it doesn’t seem that Apple checks.
 
Always had to do it before, where they install a certificate to your iPad and run it there. Who knows what changes have been made in the last couple of months.
 
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