Can I sell a consumable item with an expiration date? Is there a problem with Apple if I tell my user that he/she has 1 year to use the consumable item?
Consumable item with expiration date
I found the answer. In case anyone else wants to know:
App Store Review Guidelines
3.1.1 In-App Purchase
Any credits or in-game currencies purchased via in-app purchase may not expire, and you should make sure you have a restore mechanism for any restorable in-app purchases.