Some companies won't allow you to check the balance until you upload the card to your account — which can make it look like you're double-dipping if you try to sell it to someone else. Some companies (including Starbucks and iTunes, Hunter says), won’t allow buyers to check the balance of a gift card without linking it to an account. So, if you buy someone music and add it to your iTunes account to check the balance, it will look like someone is trying to steal your gift card if you sell it to someone else. What’s more, if merchants disable the automatic balance check, resellers may not accept that gift card.