How to protect your credit score

How do you know if your credit score is up to par? The three digit number can determine whether you get a mortgage or car insurance --- sometimes even a job.

So, is there any way to improve it if it's low?

According to CBS News Business and Economics Correspondent Rebecca Jarvis, there are ways to keep your credit score intact, and while it may take a little time to get back on track, it will help you in the long-run.

What determines your credit reputation overall and how do credit scores have an impact?

"First of all, you have a credit reputation -- and that's both your credit score, as well as your credit report. The two items together are the things that banks use, phone companies use, even, in some cases, employers use, to determine whether or not you are the kind of person that they can depend on and trust to act responsibly," Jarvis tells "Early Show" co-anchor Chris Wragge. "That credit score is a number somewhere between 300, and 850, and it can certainly change your ability to get a loan, to get a credit card, and even, in some cases, to get a job."

VIDEO: Protecting you credit score

What determines how high or low that number is?

Jarvis says, "About 35 percent of it is whether or not you pay your bills on time. But then there's another 65 percent of it that comes down to things like how much of your available credit are you using? For example, if you have a credit card that has $10,000 available of credit on it, and you're using $9,000 of that available credit, well, your credit score can actually go down, because of the fact that you're using so much of the credit that's available to you."

While it may seem insignificant if you miss a month here and there when paying your bills, it can really knock your score down.

"It can. The biggies, obviously are bankruptcy and foreclosure," Jarvis adds. "Those two items can stay on your credit report and stay on your credit score for up to seven to ten years. So in those cases, it's certainly a big deal."

How can you boost your score?

"The first thing you can do, it's easy, or sometimes easier said than done, but it's paying your bills on time. Pay off all of those late bills. Also resuscitate, use an old credit card. What that will do is give you more available credit. It will look like you are utilizing less of the available credit. Do not, however, open a new account. That can lower your credit score. And also don't close old accounts. It's OK to leave an old credit card just sitting dormant without carrying balances," Jarvis explains.

What if you've always had good credit and now you want to apply for a loan?

"You want to check that credit report and credit score before you go through that process. One of the things is, with the credit report, about a quarter of them actually have errors on them," she points out.

Jarvis suggests going to AnnualCreditReport.com where you will you find three options -- you can get three free credit reports from Equifax, Experion and Transunion.

"Those are the three companies that collect all of the data and maintain it in their systems. You want to go there and check for errors, because you don't want an error to come in between you and a loan. And sometimes, if you have an error, you go back to these companies and tell them about it," she says.

How quick a process is it if you do find errors in it? The general perception is this is going to take forever to clean up

"It takes about 30 days to really change your credit situation. But what you want to do is send a certified letter to the credit union as well as to the bank, to let them know that you see that error," Jarvis says. "First I would recommend calling up the bank itself and just saying, 'Kisten guys, I don't know what this is all about.'"