This is one case where "use it or lose it" definitely doesn't apply. For a higher credit score, almost all financial gurus suggest keeping your credit balances low in relation to your lines of credit.

Your credit utilization ratio is determined by the amount of credit you've used, compared to the amount you have at your disposal. For example, if you have three credit cards with a combined total of $50,000 in available credit, and your combined balances on the card is $25,000, your credit utilization ratio is 50 percent.

As recently as last year some financial advisors believed a credit utilization ratio of 50 percent was acceptable, but that was before last fall's credit crunch. Now, the recommended ratio is much less. Some advisors say no more than 25 percent - some say no more than 10 percent.

Unfortunately for millions of consumers, that's changing the rules in the middle of the game. Many already have a credit utilization ratio of 50 percent or higher. To make matters worse, credit card companies have begun reducing many customers' credit lines to their existing balances. That can push their credit utilization ratio to 90 percent or higher.

"I was a Washington Mutual customer with a low interest rate," Deel, or Berkley, California, told Now my credit card has been closed by Chase. I have never been late nor missed a payment."

Deel was one of thousands of former Washington Mutual cardholders who had their accounts closed by Chase, which took over the bank earlier this year. That reduction of credit made their credit utilization ratio spike upward.

"I had a Washington Mutual credit card, with a limit of $15000. I never missed a payment, was never late, always paid more than the minimum due, and paid it off last October, said Monica, of Santa Cruz, California.

With a zero balance on a $15,000 line of credit, Monica's credit utilization ratio should be very low.

"So in August, Chase decided to decrease the credit line from $15000 to $3800, she told

Unfortunately, when your credit utilization ratio goes up, your credit score goes down. The ratio is the second most important factor in determining your credit score, after timely bill payment.

In may be hard to do in this new credit environment, but consumers who find themselves with a rising credit utilization ratio should try to get another credit card and keep the balance low.

Another, more obvious step is to pay down your balances as quickly as possible. Liquidating other assets to pay off debt could provide significant benefits, if the result is an improvement in your credit score.

Why is your credit score so important? Financial services Website says raising your credit score by 30 points will save the average consumer $105 a year.