Register the card at the store. If you are buying the card for someone else, you can save them a bit of trouble by activating and registering the card wherever you buy it. Stores that sell the cards often do this automatically.
Registering Your MasterCard Gift Card
Call the telephone number on the card. If your card was not registered at the store or if you bought it online, you will need to register it by telephone.
Read the card packaging. Your card will come with materials explaining the registration process, so if you have any questions about your card's registration, refer to the instructions or call the telephone number on the card.