Gift coins never expire. If you use one for a purchase that costs less than the coin's value, you'll receive the change in form of a gift card. As all gift cards are valid 24 months from the date of issuance, you will have 24 months from the date you purchased your gift coin to spend the remaining balance on the gift card.
More details can be found in the gift coin terms and conditions.
Please note, we no longer sell gift coins in-store or online. If you are in possession of a gift coin, this is still redeemable in-store.