They say: "4 things that can kill your credit score."

Don’t Waste Your Money

All of us want a good credit score. That gives you the lowest possible interest rate next time you buy a house, a car or take out a credit card.

Thinking of applying for a home or car loan? To know your credit worthiness in advance, you can access your credit score from Equifax, Experian and TransUnion (though it will cost you a few dollars.) You can even get a free score from Credit Karma.

Ideally, you want a credit score as close to 800 as possible.

Money Magazine lists some credit score killers that can lower your score dramatically.

Late bills: Even just one late credit card payment can knock down your score 20 points or more. Pay something each month, even if it is just the minimum.
Using more than 1/3 of your available credit: In other words, don’t max out your credit cards. Just because you have $3,000 available doesn’t mean you should put $2,600 on your card.
Closing too many accounts too quickly:It’s OK to cancel one credit card, but don’t close three or four at once.

Biggest credit score killer

But from the “doesn’t that stink” file, perhaps the biggest score killer:

Don’t let anything go to collections: Even a disputed doctors bill that you know you are in the right about. It can take two to four years to bring your credit score back to its pre-collection level.

For a free estimate of your credit score, check Credit Karma.com.

Your true FICO score will cost about $10: You can access it at MyFico.com.

Your credit card company may also offer you a free score approximation.

My advice? If you are planning a major purchase soon — like a home or car — check your credit score first, even if it costs a few bucks.

It’s worth knowing so you don’t waste your money.
(Information from: http://www.wcpo.com/money/consumer/dont-waste-your-money/4-things-that-can-kill-your-credit-score)