In order to process credit cards, you need a merchant account or third-party services. These companies have contracts with major credit cards and other payment providers. If you do not agree with a payment processor, you are not able to process transactions. A merchant or processing agreement usually prohibits you from submitting credit card charges for cards issued to business owners, principals, or family members who are not involved in the purchase. Getting cashback, paying employees, and purchasing inventory for your store shouldn't be done with your personal credit card.