Wendy J. Fox has never been more concerned with getting a perfect credit rating. Yet in December 2019, just a month after quitting his full-time job, his score hit a perfect 850.

Although The FICO scoring model does not officially count earnings as part of her algorithm, Fox was nonetheless surprised that such an exploit occurred right after she stopped earning a regular salary.

Fox was making enough money as a freelance writer, but his income was definitely irregular. She was certainly more concentrated on writing his next novel than earning a regular salary. But in retrospect, freelance work may have helped Fox score more than she thought.

Below, Fox shared with CNBC Select what her financial situation looked like before getting perfect credit, how irregular income may have helped boost her score, and what she has since learned about FICO’s scoring model.

Fox’s mom worked in a bank, so Fox knew from a young age how to keep good credit and did so for most of his adult life – but it was never perfect.

“I knew a lot about FICO and I was never without a bank,” Fox told CNBC Select. “It is a mark of privilege in itself.”

But like many university graduatesFox struggled with a student loan and credit card debt early in his career. After graduating with her Masters of Fine Arts, she had approximately $ 26,000 in credit card debt and $ 30,000 in student loans. She first looked at her credit score in 2005, and recalls that it was below 600, which would have put her in the subprime credit Category.

“I remember thinking, ‘I would like to buy a house, but can I? “, Says Fox.

Over the next two years, Fox committed to learning the ins and outs of credit rating so that she can qualify for an affordable mortgage without having to make a huge deposit. She used her only credit card for her daily expenses and paid off the balance in full each month. This has helped her establish an on-time payment record and reduce her total credit usage. (These are the two main factors of get a good credit score).

In 2007, Fox’s score wasn’t perfect, but it was good enough that she could get a mortgage to buy her first home, a Seattle townhouse that turned out to be a worthwhile investment.

Experts say that a a credit score of around 760 will give you all the same benefits like someone with a score in the 800s.

Fox has worked in corporate marketing for most of her career, and she says that’s one of the reasons she was so financially stable. But even working full time, she was able to write three books, including her latest novel, “If the ice had held“, a first Buzzfeed choice for 2019.

When she decided to take the plunge and become independent full time, she also changed her finances. And she thinks those changes might have helped her achieve a perfect credit score.

“My spending habits have really changed,” says Fox. “Sometimes you get paid a lot and sometimes you get paid nothing”

She is much more careful when she pays her cards every month. Fox now refunds her card every time she makes a purchase and keeps it balance close to $ 0.

“When you are self-employed, have no credit card debt,” she advises. “You don’t know when your next paycheck is coming. “

Another factor that probably helped Fox’s score reach a new high is his credit history, which is the third most important. factor for your FICO credit score. Unfortunately for Millennials and Gen Z consumers, the only way to improve this part of your score is by keep your oldest credit card open as long as it doesn’t cost you.

One way for young consumers to start building credit is by becoming a Authorized user on someone else’s credit card. If a close friend or family member is willing to tag you on (and share the blame), this is an easy option.

Many issuers do not charge cardholders to add an authorized user to their account, including the Chase Sapphire Preferred® Card, the Capital One Venture Rewards Credit Card, the Bank of America® Cash Rewards credit card and the Citi® Double Cash Card. But some premium credit cards – for example the Chase Sapphire Reserve® – have an annual fee for the authorized user.

If you do not have the option to be an authorized user, secured credit cards are the best way to build credit. You can later upgrade them to an insecure card.

While Fox is happy to have a perfect credit score, she says her story is a good example of why your FICO score is just a measure of your overall financial health.

“I sometimes complete [my spending] with savings, ”says Fox, noting that her FICO score has nothing to do with her net worth or the number of assets she has to her name.

While your income level is not directly related to your credit score, Fox believes it can have a major impact. “It’s a lot easier to use less credit when you have a higher income,” she says.

Likewise, Fox adds that if you’re good at managing your finances, having a lower salary doesn’t necessarily mean a lower credit score. FICO only measures the quality of your credit management, and managing your money is more than that.

“I bet there are people who are great fund managers who primarily use cash, but that won’t translate into a FICO score down the line, which is fundamentally unfair,” says -she.

And a lot of people who have no debt and excel in economy the money is actually invisible credit.

If you are in this situation, a new service called Experian Boost can help you improve your credit score by reporting your rent, utility and internet payments on time to the credit Company Experiential. Average users see their FICO^® The 8 score increases by 13 points, and many become outstanding for the first time.

So during credit reports and credit scores isn’t everything, Fox advises newcomer credit to understand how credit works and how to use it to your advantage.

The Capital One Venture Rewards Credit Card and Bank of America® Cash Rewards Credit Card information was independently collected by CNBC and was not reviewed or provided by the card issuer prior to posting.