Credit reports play a big part in your financial life, but they’re still a mystery to many people. Here’s a complication of some basic things you should know about credit reporting.

There are more than three credit reporting agencies. While Equifax, Experian, and TransUnion are the most mentioned (and largest) credit reporting agencies (better known as credit bureaus), they aren’t the only companies in the United States who compile and distribute credit reports.

There are dozens of smaller, less well-known, and less used credit reporting agencies that also house consumer credit data. You have the same rights with these smaller credit bureaus as with the major ones.

FICO does not maintain your credit report. FICO, formerly known as The Fair Isaac Company, is the company who created the FICO credit score. While the score is based on credit report data, FICO itself is not a credit bureau and doesn’t have its own credit report. Instead, FICO gets permission from credit bureaus to sell credit scores based on the bureaus’ credit reporting data.

Your credit reports are not identical. Compare your credit reports side-by-side and you’ll quickly see that there are differences between each of them. The discrepancies aren’t a big deal unless one or more of your credit reports has listed inaccurate information or doesn’t include critical details like your credit limit. You have the right to dispute inaccurate credit report information with the bureau that provided the report.

Credit bureaus receive data from “information furnishers.” The credit bureaus create your credit report based on information received from creditors, lenders, debt collectors, and other companies. The integrity of your credit report data is largely dependent on what your creditors send to the credit bureaus.

If you’re looking for someone to blame for negative information appearing on your credit report, look to the company who furnished that information. Again, you have the right to dispute inaccurate information and the credit bureau will investigate your dispute.

The credit reporting agencies don’t decide the fate of your application. Creditors, lenders, and other businesses use your credit report to decide whether to approve or deny your applications. However, the credit bureau does not make any decision about your application. If you’re denied, it’s because your credit history or other qualification factors didn’t meet the creditor’s criteria.

Creditors report to credit bureaus by choice, not law. Checking your credit report, you might notice some of your accounts don’t appear. That’s because businesses aren’t required to add information to your credit report. Instead, businesses choose whether to report to the credit bureaus. However, once a creditor establishes a relationship with the credit bureaus, the credit bureau will probably establish a contract requiring the creditor to report accurate, timely information.

Your checking account isn’t listed on your credit report. Many of your financial accounts are listed on your credit report, but those accounts listed involve an extension of credit. Your checking, savings, and other investment or retirement accounts aren’t normally listed on your credit report. But, if those accounts have an unresolved negative balance, that delinquency could be reported to the credit bureaus.

Credit reporting agencies don’t make the rules. Credit bureaus are required to abide by the Fair Credit Reporting Act, a Federal law that provides guidelines for credit reporting agencies. The FCRA says, for example, that your credit report should only be provided to businesses that have a “permissible purpose.” The law also specifies how long credit bureaus should report certain types of information.

Credit scores aren’t automatically included. More businesses are making use of credit scores, which essentially grade your credit report. While credit bureaus are required to make your credit score available to you, the score isn’t automatically included with your credit report. You typically have to pay an additional fee to access your credit score, unless you get it through a third-party that offers free scores.

CreditKarma.com, CreditSesame.com, and Quizzle.com are a few websites that offer free credit scores with no strings attached.