A new survey from Bankrate.com found that 40% of adults in the U.S. with a live-in partner have committed financial infidelity. Younger generations were more likely to keep money secrets: 67% of Gen Zers said they have confessed at least one instance of financial infidelity, followed by Millennials at 54%.

What sort of things are they hiding? 33% are spending more than their spouse or partner would be cool with, and 23% have racked up debt that their partner has no knowledge of. Others keep secret credit or savings accounts.

Avigail Lev, director at Bay Area Cognitive Behavioral Therapy says, “Choosing to be private about where and how you spend your money is just privacy. (But) having agreements with your partner about how you use money and hiding it on purpose, lying or deceiving, that’s financial infidelity.”

Money is one of the leading causes of divorce, yet often couples still struggle to communicate openly about finances. CPA Melisssa Pavone says, “Many couples never unpack their financial history and beliefs, leading to misunderstandings and resentment. Without open dialogue, secrets fester and financial infidelity can erode trust — just like physical infidelity.”

Why would someone who loves you deeply be dishonest about money? CPA Emily Luk says, “Sometimes it’s about guilt or fear — worrying that their partner won’t approve of a certain purchase, or that an old financial mistake might scare them off. Other times, it’s a way to avoid conflict or keep the peace. They might think it’s easier to conceal credit card statements than to have a tough conversation."

There can be differences in couples' money personalities and values: One is a spender, the other a saver. But money can also take the form of power, control, safety, past financial trauma, or even a mental health issue, substance use, or gambling disorder.