6 ways to kill your credit score

Lenders, insurers, landlords and others will charge you more or flat-out reject you if you show up with a low FICO score. Here's how you may be doing yourself harm.

How your score affects your auto loan rate
For a $25,000 36-month auto loan
FICO score APR Monthly payment
720-850 7.115% $773
690-719 7.934% $783
660-689 9.404% $800
620-659 10.960% $818
590-619 14.404% $859
500-589 15.020% $867
Source: myFICO.com; rates as of May 7, 2007
Be too thin
When it comes to your credit record, fat is good, emaciated bad.

Even if you're the most responsible, on-time, in-full bill payer on the planet, your credit score won't be as high as it could be if you have just one credit account.

The reason: Your credit profile is too thin and lenders ideally like to see a potential borrower responsibly managing a mix of revolving debt (such as credit cards, where you can reuse the credit after paying it back) and installment debt (such as a car loan or most mortgages, where you pay the same amount every month for a certain period).

To boost your score: Consider opening another credit-card account or two, or taking out a car loan or small bank loan.

Be a bad-timing big spender

Be a slacker

Be too thin

Be too young and eager

Be too tidy

Be too nonchalant
Saving and spending aren't the only factors affecting your net worth. How you manage (or don't manage) your assets and liabilities can make a big difference, too. (more)
You don't have to spend a lot of time to put your financial house in order. (more)