Credit scores greatly impact a consumer's financial moves — and how much they'll pay along the way — yet many don't even know how the rating works.

Around 40 percent believe, incorrectly, that age and marital status play a role in their three-digit score, according to the Consumer Federation of America and VantageScore Solution's annual credit score survey, which included interviews with some 1,000 people from May 31 to June 3 of this year.

Only around 20 percent of people fully realize how a low credit score can bring on heftier interest-rate charges. Specifically, that borrowers with a low score can pay about $5,000 more on a $20,000, 60-month auto loan than a person with a high score.

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Just around half of the people surveyed could identify the three biggest ways they can lift their scores.

Here's how: Keep balances below 25 percent of the credit limit, don't hold too many open accounts at once, and make payments on time.

"If you are four days late on a credit card bill, your score can go down 30 to 40 points," said Steve Brobeck, the executive director of the Consumer Federation of America.

"Most consumers don't seem to understand how important credit scores really are in their financial lives," Brobeck said.