Visit WalmartMoneyCard.com/activate or select Activate your card in the Walmart MoneyCard app or call (866) 946-2510. 2. Enter all info requested, including personal info and card details: – Name – Address – Date of birth – 16-digit card number – Expiration date – 3-digit security code (found on the back of your card) – Mobile phone number 3. Start using your card upon successful activation.