There are five parts to your credit score. Payment history (35%), amounts owed (30%), length of credit history (15%), new credit (10%), and types of credit (10%). FICO, a financial analytics firm, uses these categories to rate consumers’ credit risk with a three-digit score. Within each category FICO outlines one to seven factors that come into play.

For example, in the payment history category, credit rating agencies consider how many accounts you are up to date on, whether you have any negatives like a bankruptcy or liens, and how long an overdue bill has been past due, among other factors.

In the length of credit history category, they consider how long it’s been since you opened an account, how long each specific account has been open, and how recently you’ve used each account. Read all the factors that are considered for each category of your credit score.

This is important stuff to know, but unfortunately the three credit rating agencies, TransUnion, Experian, and Equifax, don’t share specifics. How many points do I lose if I have a bill past due seven months instead of two? How many points do I gain if I am paid up on three accounts instead of one?

More information would help consumers improve their score. In the meantime, AARP shared tips for seniors and everyone else on how to improve your credit score or hurt your score. When in doubt, use common sense.

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Get a free credit history report (sans FICO score) through the FTC