How to set the PIN on your Mastercard. Credit Cards: 844.334.3874 (the number on the back of the card) Option 7 and follow the prompts Debit Cards: 800.472.3272 (number on the back of the card) or 800.922.3808 (card self-service) Option 1 for activation and follow prompts Have more questions? Submit a request 0 Comments Article is closed for comments. Related articles How do I receive a PIN (Personal Identification Number) for my Mastercard credit card so I can access cash? Why is my 3Rivers debit or credit card being declined? Will I receive a PIN (Personal Identification Number) so I can access cash with my debit card? Debit Card Blocked States and Countries Mastercard debit card or Mastercard Credit Card was lost or stolen. Who should I call?