Bickering about money is the top source of friction among couples in the United States, trumping disagreements over kids, work, chores — even sex. While money battles are common in all relationships, they often peak when couples hit their 50 and 60s, according to a new survey conducted for the American Institute of Certified Public Accountants by Harris Interactive.

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The AICPA survey found that couples of all ages average three arguments a month about financial issues. But those between 45 to 54 report an average of four such disputes per month.

Furthermore, 36 percent of couples in the 55 to 64 age group, and 20 percent of married partners age 65 and older, argue about money, compared with just 15 percent of those 18 to 34 years old.

Fortunately, money disputes don't have to drive a wedge between you and your mate. Below are some pointers for resolving them — before they become problems.

1. Spending habits

He thinks she spends too much on clothes, jewelry or handbags. She accuses him of extravagance about travel, entertainment and leisure. Sound familiar?

Can't agree on finances? You're not alone. But peace is possible. — Photo by Randy Faris/Corbis

According to the AICPA survey, the root of this discord is differing opinions on what constitutes spending on "needs" versus "wants." Fifty-eight percent of people who argue about money say that's the most common cause.

"You might think that since they're older couples, especially if they've been together for a while, they would have figured it out," says Kelley C. Long, a Chicago-based money coach and member of the National CPA Financial Literacy Commission. "But it doesn't matter how old you are, everybody needs a little bit of autonomy with their money."

The way to end such arguments, Long says, is not by compromising, but by coming to an agreement over major purchases.

"Set the bar for a major purchase," she says. "For one couple, it might be $50 and for another it might be $500."

But why an "agreement" and not a "compromise?"

"An agreement means you discuss your options, pick what's best, and you both say 'Yes, this is acceptable to me,' " Long says. "A compromise means there's been a concession by one or both people, so you wind up saying: 'I don't like this, but I can live with it.' "

Such compromises inevitably breed resentment or fail to last, Long adds.

Next: Clashing over money that goes to relatives. »