Q. A credit score I got off the Internet differs from what my mortgage lender says is my real score. I'm wondering if they're trying to pull a fast one on me.

A. Sorry to break the news to you, but there can be problems when comparing credit scores you get online with those that are used by your lender.

There are lots of people who've gone to borrow money thinking they've got a high score, only to find out the score that lenders are using is much lower.

"What they see is not necessarily what they get," said Rueban Subramaniam, a manager for Credit Bureau of the Pacific in Honolulu.

Subramaniam said he's heard of a consumer purchasing a score off the Internet that was about 75 points higher than the one used by the bank.

Don't let this situation turn you off from getting your scores. It's a good idea to know your credit standing why you received the score you did.

To understand why scores can vary, you need to know a little bit about how this all works. To start, credit bureaus collect your financial history from companies that have loaned you money or extended you credit.

This credit report contains information on what types of accounts you have, how timely you make payments, how long you've held accounts and other information.

The report also serves as the basis of your score. Credit bureaus plug the data into scoring models to come up with a number that banks, car lenders, credit card companies and others use to decide whether they want to do business with you and what interest rate to offer.

In 2003 Congress mandated credit reports used in processing mortgage applications be made available to consumers annually for free. It stopped short of mandating free access to scores, only requiring bureaus to make some type of credit scores available to consumers for a reasonable fee.

Here's where the confusion starts.

There's been a proliferation of scores offered on the Internet and little explanation of how these differ from one another or whether they resemble those obtained by lenders.

"Probably the predominant myth is that there is only one credit score," said Rod Griffin, manager of public education in Dallas for Experian Ltd., one of the three national credit rating bureaus furnishing scores to lenders.

"There are more than 1,000 scores used by lenders and businesses to make lending and risk decisions."

So which one do you pick?

You probably want to focus on credit scores that are formulated using the "FICO" scoring system. Fair Isaac Corp. (FICO) helped develop what is probably the most used scoring model and claims that 90 out of the top 100 U.S. banks use the scores. Most mortgage lenders use what's know as FICO scores in deciding on your loan application.

"The FICO score is the 800-pound gorilla in the financial scoring business," said Craig Watts, public relations manager for Fair Isaac.

The FICO scores range from 300 to 850, with the top end of the range being considered excellent and the low end a bad credit risk.

FICO scores are available to lenders from all three national credit bureaus, Experian, Equifax and TransUnion. It should be noted that FICO scores from the three bureaus can vary since information in the companies' credit reports can be different or even contain errors.

You can get the FICO scores at Equifax's Web site and at MyFico.com.

At Experian's site, you will be offered "Plus" and "Vantage" scores, each of which uses different scoring systems. Scores under the Plus offering run from zero to 1,300, with zero being best. Under Vantage, scoring is more like the grading systems used by schools with the scores ranging from 500 to 990. Someone with a 990 score would have A-plus credit.

You should also be aware that there can be different scoring systems if you're trying to get a car loan, get a credit card or rent an apartment. These can place greater scoring emphasis on how you've paid off past car loans or factors related to a specific business.

Confused?

Just remember whatever the scale or scoring model, you should be able to get an idea of whether you've got excellent, average or bad credit.

Do you have a question about personal finance, taxes or other money matters? Reach Akamai Money columnist Greg Wiles at 525-8088 or gwiles@honoluluadvertiser.com