When it comes to money, it’s hard to be honest, even with the ones we love the most. According to a new survey, nearly one in three people commits some form of financial deception in their relationship. Financial transgressions, according to the survey commissioned by the National Endowment for Financial Education, included such things as concealing a purchase from a spouse, keeping a secret bank account, hiding cash from a partner, lying about debt, and hiding income.

But are all financial transgressions equally egregious? Is there a difference between fibbing about the price you paid for a new pair of shoes and hiding cash from your spouse in a hidden bank account? Some experts claim that even minor financial transgressions are an affront to the foundation of trust on which all marriages are built. Small financial lies can lead to even bigger financial betrayals down the road.

“More marriages fall apart for financial reasons than for fidelity reasons. Fundamentally, marriages are built on trust, and anytime you breach the trust of the other party, it damages the relationship,” explains family law attorney Steven Mindel in an interview with Business Insider.

So why do people commit financial infidelity? Reasons vary, but sometimes it’s the result of power dynamics in the relationship. A spouse who, for instance, brings in the lion’s share of the income may feel entitled to control and dole out money as they see fit to their significant other. Their partner, in turn, may commit financial infidelity as a way to rebel against the one-sided nature of money in the relationship.

Financial infidelity may arise as a result of different money beliefs. A “saver,” for instance, may feel the need to hide money because of the irresponsible free spending ways of a spouse. Still, other acts of financial infidelity are committed when one spouse resents having to tell their significant other about each and every purchase they make.

Experts agree that communication is the key to preventing financial infidelity from rearing its ugly head. Our money beliefs are the accumulation of a life time of experiences. As a result, no two people will approach money issues exactly the same way. That’s why it’s crucial for couples to honestly discuss their money beliefs and learn to compromise to reach a happy medium.

If one spouse is a “saver” and another a “spender,” for instance, agree on certain financial goals while at the same time setting an allowance for each partner to spend on whatever they choose. If one partner is domineering when it comes to money, now is the time to discuss it openly before it leads to problems later. Does a partner resent having to check in before making a purchase? Consider setting up an “ours”, “me”, and “me” account. One major bank account is used for all the major expenses while each partner has a separate smaller account for personal spending. Alternatively, a couple can agree to discuss with each other only those potential purchases that exceed a certain dollar amount.

By communicating and laying the ground rules early, you’ll keep financial deception from driving a wedge in your relationship.

BMWK, do you think an occasional financial fib is OK in marriage? Have you or your partner ever been guilty of financial infidelity?