Check My Gift Card Balance. To check gift card balance, you will need the card number and, if applicable, the PIN or security code located on the back of the card. Most retailers & restaurants allow you to check the balance online, by calling the toll-free number located on the card, or by visiting them in person. It can vary brand to brand what works best. In stores just present the Walmart gift card at checkout. Online enter the gift card number and the PIN, which is listed on the back of gift card, during checkout. The PIN provides a more secure online shopping experience. As you make purchases, the gift card amount decreases. You can add to the gift card balance anytime at a Walmart store. Check your Gift Card Balance on Gift Cardio by selecting a Store or Brand below, to choose from one of the thousands of stores we support. Everyone from Restaurants to Retailers are listed below, we constantly search the web to give you a quick and easy way to check your balance.