A new study by Fair Isaac, the company that created the FICO score, shows that the credit ratings of 24 million borrowers decreased on an average of 20 points after credit card issuers lowered ratings late last year. The frustrating things about this study is that the rating decrease wasn’t due to late payments or any misbehavior on the part of the borrower. Instead, the ratings changes because the utilization ratio increased for the borrowers whose rates were decreased. The utilization ratio is simply a measure of how much money has been borrowed compared to available lines of credit. In general, the higher this ratio, or the more people borrow compared to how much they could borrow, the lower your rating.

If you’re looking to borrow for a home or car, you may want to check your current score by checking the credit reports that you can get for free. A 20 point drop is enough that you may not qualify for the same rates as you could before.

Read more about this study at USA Today.
Download your free credit reports here.