Millennials need guidance when it comes to building and maintaining healthy credit habits, TD Bank reported Tuesday.

This comes at a time when four out of five millennials believe society will eventually become cashless.

A TD Bank survey found that 23% of millennials do not have a credit card, and are the age group most likely to prefer cash while traveling.

Half of millennials reported using between 31% and 90% of their credit limit, well over the recommended utilization rate of 30% or less. Thirty-two percent put their credit health at risk by failing to fully pay off their cards each month.

A quarter of millennials did not know their credit score. TD Bank said this could handicap them when applying for credit cards or loans, getting approved for a mortgage, buying a car or making other major purchases.

“The data is a bit concerning — it shows that a significant knowledge gap exists for millennials when it comes to credit, especially compared to prior generations,” Mike Kinane, head of U.S. Bankcard at TD Bank, said in a statement.

“We’re relying less and less on cash, and while credit cards may not be a millennial’s payment method of choice, it’s still critical that they develop financial knowledge and habits to properly position themselves for sound credit health down the road.”

MARU/Matchbox conducted an online survey and interviews in March 2017 among 1,002 consumers, and followed with a second survey among 1,000 respondents in August 2018, using the Springboard America panel to speak with 1,000 consumers.

According to the survey, 30% of millennials have let their credit card rewards expire, compared with 14% of Gen Xers and 9% of baby boomers, even though they are likelier than other generations to pay for a group outing in order to earn rewards.

TD Bank said this finding was surprising given that millennials were the generation most likely to carry a balance on their credit card.

In addition, millennials spent $2,447 annually on dining, well above the $1,923 Gen Xers spent and $1,486 boomers spent.

TD Bank noted that if millennial restaurant goers were using a card with 2% cash back on dining, they could be earning nearly $50 in rewards each year. It said that could pay for more than two weeks of coffee from a coffee shop, or nearly four months of a Netflix subscription, citing a UBS study.

About two in five millennials in the study said they were willing to help their children establish credit through a secured card or help with student loans. At the same time, 55% of all survey respondents — and 70% of boomers — said they were not willing to help their children establish credit.

“Perhaps born out of growing up during the financial crisis and feeling the impact of student loans, millennials are driven to set their kids up for financial success and teach them good financial habits,” Kinane said.

“Through education and options like secured cards, younger generations can learn the responsibilities of having a credit card and start establishing good credit at a young age. It’s also worth noting that length of credit history is a significant factor in credit scores.”