Q: I am currently renting a house with an option to purchase it later this year. I tried to get a mortgage recently and found out that my credit history has problems and my credit score took a dive.

My score was nearly 600 and I tried to fix the problems on my credit history last July by disputing some errors. Instead, my credit score went down.

I have six months before the option is due. What if anything can I do to get my score back up?

A: I’m wondering why your credit took a nosedive recently. Were you late paying any bills? Did the disputed items really come off of your credit history or did they reappear because you failed to prove they were errors and not accurate (although negative) information?

Every time you get rejected for a loan, it will negatively impact your credit history and score. So pull your own copy of your combined credit history from all three credit reporting bureaus and try to analyze what is dragging down your credit score.

It’s possible that you have recently cancelled the credit card you have had for a long period of time or have charged above 30 percent of your maximum available credit limit on one card. It is also possible that the errors never came off your report and have reappeared to do additional damage.

It can normally take six months to a year to improve your credit score, but here are some ideas for fixing your score over the next 30 to 60 days:

First, pay off any credit cards or lines of credit that you may have. You want to lower your “debt utilization ratio,” or the difference between your balance (zero balance is best) and your maximum available credit limits.

Next, don’t charge on your credit cards if you can help it. In fact, you should focus on paying off any balances you have. But don’t cancel or close accounts once you’ve paid off the balance. That can hurt your score as well.

Work on correcting any big mistakes on your credit score, and use the three major credit reporting bureaus online dispute process. Your information will be processed more quickly. Just make sure to keep a printed copy of whatever you send to them.

And, make sure all of your creditors are reporting your on-time payments to all three credit reporting bureaus (Experian.com, Equifax.com and Trans-Union.com).

When your lease expires, you will probably have the option to renew it again, which should give you more time to correct any credit history problems.

But, you might also be able to work out a deal where the seller takes back your mortgage. If you can purchase the house with the seller as your lender, you will have taken a big step forward in fixing your credit. You might also want to see if you qualify for an FHA loan with the credit you currently have.

Finally, remember that no one else can fix your credit history. So, steer clear of so-called “credit repair” companies that charge you huge upfront fees to “fix” your credit. They’re not fixing your credit and you could wind up in worse trouble — plus you’ll be out a lot of cash.

Jan. 14, 2005.