A merchant account is an account at an Acquiring Bank and is used to fund you for your credit card transactions. You need a merchant account in order to accept and process credit card transactions, have those funds deposited directly into your bank account and have your organization's name on the donor's credit card statement. In order to use 4aGoodCause, you'll need to set up an Internet merchant account as well as a payment gateway with one of the providers we support.

The majority of 4aGoodCause clients have set up a merchant account with Dharma Merchant Services 

More information:  

How credit card payments work