Improving your credit score can be as simple as asking for a higher card limit. Really, it's true.
The trick is to ask for a higher limit on your existing cards. However, most people don't bother, according to a new report from Bankrate.com, which surveyed 1,000 people ages 18 and older by phone April 14-17.
By increasing your credit limit — assuming you don't go on a spending spree — you reduce what's known as your utilization ratio, which boosts your credit score.
While 8 in 10 Americans get approved for a higher limit, less than 30 percent of cardholders surveyed asked for one. And your age helps. Those over age 30 are much more likely to get approved compared with younger millennials, the study found.
"It's a good time to be negotiating anything with a credit-card issuer, because banks are doing whatever they can do to attract new customers," said Matt Schulz, CreditCards.com's senior industry analyst.
Your credit utilization ratio is a percentage calculated by adding up your outstanding balances divided by the available credit limit on all your cards. Increasing your limit lowers this ratio (assuming you keep spending in check).
Keeping spending to 30 percent or less of your limit is best, according Beverly Harzog, a credit card expert and author of "The Debt Escape Plan."
The survey also showed that nearly half of respondents have either never checked their credit scores or do so very infrequently — less than once a year.
Of the millennials surveyed, about 33 percent weren't very likely to check their scores.
"They're at a point in life where they don't need to check," said Bankrate analyst Mike Cetera. "They check them when they apply for a big loan. When you're 18, 19, 20, odds are they're not in the market for that."
People have grown more aware of the importance of checking on credit scores since the Great Recession, Harzog says. She recommends checking your score every few months or at least once a year, depending on your financial situation.
The good news for younger millennials is getting an increased credit limit is not out of the question for those with a history of responsibility, Harzog said. An issuer may still consider a request even by those with a shorter credit history.
This article originally appeared on CNBC. Read more from CNBC: