How this 54-year-old Alaskan oil worker got a perfect credit score

A good credit score is key to your financial future — here's how to boost...

Shawn Nelson, a 54-year-old heavy equipment operator who works in the Alaskan oilfields, has a perfect credit score.

"I hit 800 a few years ago, and then I went to a 820, and then 830, and I was like, 'S---, I'm going to try do this,'" he tells CNBC Make It.

In March, his FICO Score 9 hit 850. That's the highest you can go using the latest version of FICO's base scoring model, though other scores specific to different types of loans range further.

"Only the top 1 or 2 percent of people will have a 'perfect' 850 credit score," Rod Griffin, director of consumer awareness at Experian, tells CNBC Make It. "And it probably won't stay that way. Scores move up and down as your credit history changes. If you increase your balances, open a new account, or have old information fall off your report, your score might slip down or bounce back up."

But if Nelson continues to be diligent, his score could stay perfect.

Here's what he did to get to 850, which he shares because "hopefully this can help somebody out there."

He keeps his balances low

Nelson has eight open credit cards, including one store-brand card and one with an annual fee.

Most people with excellent scores have an average of three open cards and three that have been closed, according to a recent FICO analysis. Nelson says he uses two or three at a time and then rotates after a year or two to ensure issuers don't close any of his accounts, since that can hurt your score if it reduces your credit limit. Nelson's limit is just over $100,000, which allows him to keep his utilization ratio low. It rarely exceeds 5 percent.

If you're planning on managing this many cards, "you got to be responsible," he warns. "It can get dangerous."

Shawn Nelson, 54, on the Kenai River in Soldotna, Alaska
Source: Shawn Nelson

He has multiple lines of credit

Having a balanced mix of different types of credit accounts for about 10 percent of your FICO score. In addition to credit cards, Nelson has a mortgage, a home equity line of credit and multiple auto loans.

In the past 10 years, he's bought three used cars. He likes to pay for half up front and the remainder over the course of a four- or five-year loan. His mortgage is also half paid off.

He's paid bills on time for 30 years

Nelson hasn't been late on a payment since he was in his 20s, which he says is largely thanks to having a consistent paycheck.

"Having a steady job and being able to pay your bills on time — I think that's where a lot of people can get messed up, out of work for a while," he says. "Of course, all it takes is a couple late payments and that'll plummet your credit rating for several years."

You don't need 30 years of perfection to achieve an excellent score, though. All it takes is a few years of good credit history, according to Griffin. And the experts agree that any score in the excellent range, higher than 750 or 760, will usually get you the best deals. "Higher scores than that are icing on the cake," says Griffin.

With a 700, you'll usually at least qualify for a loan. By contrast, if your score falls below 650, you may have trouble getting accepted for a loan or finding a decent rate.

Nelson says the biggest benefit of his score has been low rates on his loans: "I've probably saved $1,000 a year on interest over the past ten years."

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Here’s how to achieve the perfect credit score