Pay Off the Card
Pay off a MasterCard before you attempt to close the account. Alternatively, transfer the balance to another credit card. You want the balance to be zero before you call customer service.
Customer Service Phone Call
MasterCard credit cards have a customer service number on the back. You can also find the number on your contract and on your billing statement. If you can't locate the specific number, call the general customer credit number for MasterCard in the United States: 800-622-7747. First, confirm with the customer service agent that the balance on your card is paid off. Then advise the agent that you are calling to cancel your card. Be firm as the agent attempts to change your mind.
Customer Service Letter
If you cancel by phone, ask the agent for an address for a follow-up letter confirming your decision to cancel the account. Alternatively, get the mailing address for the card issuer from a billing statement or the company website. Write a letter giving your name and address, the card number, and the date and time you canceled the card by phone, and asking for a written confirmation of the account cancellation. State in the letter that you want the record to reflect that the card was closed at your request. Send the letter certified or return receipt requested to confirm its arrival. Check your credit report after a few months to check that it reflects the card's cancellation, including that it was at your request.