Good news if you ever want a mortgage or to refinance.

Your credit score, the controversial statistic that lenders use to judge your credit risk, must be disclosed if you're borrowing to purchase or refinance a one-to-four family home. There are some exceptions to this rule. The lender needn't disclose your score if you're using the loan for business purposes, or if he or she orders a credit score, but doesn't use it to underwrite the loan.

This new rule, part of the Fair and Accurate Credit Transactions Act, only applies to home loans. If you otherwise want to check your credit score, you may have to pay for it.

Credit scores, which can be subject to change daily, are very important -- even if you don't borrow.

Most credit card and loan interest rates are based on credit scores. And many insurance companies use credit scores as one factor in determining your rates.

If you fail to pay parking tickets, library fines, or other municipal services, you could be surprised to see an increase in your loan or credit card rates. Reason: More towns are giving unpaid parking tickets to collection agencies -- a factor that can trigger lower credit scores. More loans have provisions that allow for rate increases if your credit situation changes.

Employers, landlords and cell phone providers also may be influenced by credit scores.

Don't be confused by this number. There's more than one type of credit score, although the credit bureaus recently announced that they'll soon issue one uniform score. Nevertheless, whenever you check it, you need to know the company's ranges and what they mean. Currently, they may range from 200, to as much as 999. Generally, a bad score is below 620.

You might have heard of the widely used "FICO" score, named for its issuer, Fair Isaac Corp. That company's most popular score ranges from 300 to 850.

Say you applied recently for a $216,000 30-year fixed-rate mortgage: A great FICO score of 760-850 would have gotten you a low 5.8 percent interest rate. By contrast, if your score ranged from 620-639, your interest rate would be 7.39 percent. The high credit score saves you $226 monthly on that loan.

Not pleased with your credit score?

About all you can do is obtain your credit reports, upon which the credit score is based. Correct errors. Also, be sure outdated bad information is removed by writing to the credit reporting agencies. Those are:

Equifax: 1-800-685-1111; www.equifax.com

Experian: 1-888-397-3742; www.experian.com

TransUnion: 1-800-916-8800; www.transunion.com

You're entitled to one free copy of a credit report annually from each of those major credit bureaus. But don't call the credit bureaus or you'll probably be charged. To qualify for a free report, visit www.annualcreditreport.com, call 1-877-322-8228 or write: Annual Credit Report Request Service, P.O. Box 105281, Atlanta, GA. 30348-5281.

Accurate negative information may stay on your credit report for seven years. Bankruptcy information may be reported for 10 years, and, in certain cases, longer.

Information about an unpaid judgment against you typically can be reported for at least seven years. There's no time limit for:

Information on criminal convictions.

Information reported in response to an application for a job that pays more than $75,000 annually.

Information reported because you've applied for more than $150,000 worth of life insurance or credit.

The most important factor in determining your credit score is whether you pay your bills on time. If you've had a late payment, get payments up-to-date and keep them current. Low loan balances also help.

Trying to build or rebuild your credit? Confirm in advance that the financial institution you select for a new loan will report all future on-time payments to the credit bureaus. Then, get a copy of your credit report to make sure it does.