With every application for a new merchant account, the underwriter is going to pull a credit report on you. The importance of this credit report should not be ignored. Even if you have current processing history, great tax returns, lived in the same place for years, etc, a bad credit report will often be the difference in whether or not you will get your new merchant account.
The Consumer Financial Protection Bureau (CFPB) recently published this white paper on the top three credit bureaus in the US. This paper covers a lot of topics and if you ever wanted to understand the Credit Bureaus and how the information is obtained and used, then this is a must read. http://files.consumerfinance.gov/f/201212_cfpb_credit-reporting-white-paper.pdf