Do AP's expire if never used?

[Cheesehead9]

I'm thinking about buying AP's now before the prices go up, even though our trip is months away.

If I buy now, is there a date by which the AP's need to be activated - or could I theoretically come back in 5 years and begin my 365 days of use at that point?

 

[Cheesehead9]

I called Universal and they confirmed the passes "technically have no expiration date, other than 365 days after you first use them."