It’s either the stuff of nightmares—or a normal, everyday part of life. Financial advisors who cater to wealthy clients say a loan to another family member can be the answer to a lot of problems, but caution that they can raise just as many issues as they aim to solve.

“When money’s involved, family isn’t always family. Sometimes money trumps family,” says Jon Ekoniak, a partner at Bordeaux Wealth Advisors, based in Silicon Valley.

Loans between family members—usually, but not always, from an older person to their children or grandchildren—may be best ventured with the help of financial advisors who have experience setting them up. Professional guidance can make the situation more comfortable for family members unaccustomed to transacting business with each other. It’s also safer, as intra-family loans may have implications ranging from taxes to legal issues.

Ekoniak describes one example of parents with a grown daughter who’d married someone who “bounced” from job to job. The young couple wanted to have children, but could only afford a small rental apartment. After nearly a year of agonizing over different ways to help the couple, the parents finally decided to simply offer them a loan to buy a house. 

“They set up a trust fund and 50% of the income from the trust would be used to pay back the loan,” Ekoniak says. The loan repayments were interest only, at the government’s prevailing “applicable federal rate,” which is the lowest rate the IRS allows for private loans.

It seems straightforward—the “Bank of Mom and Dad” has long been a normal part of young adulthood in America, after all. But there are plenty of possible pitfalls to keep in mind. 

If nothing else, loans “should be money that the parent is willing to turn into a gift,” says Mark Weiskind, founding partner at Independence, Ohio-based Fairway Wealth Management. “You’re very unlikely to push hard to collect from your child.” 

In some cases, that impulse may be communicated up front, with the lenders explaining that they’d like to receive repayment according to a particular schedule but are flexible if the borrowers can’t make a payment for some reason. But even lenders who do expect their borrowers to stick to a particular repayment schedule need to be flexible, experts say. 

What’s more, Weiskind says, “You have to be willing to accept a lower interest rate” on a loan than you might otherwise. In other words, don’t expect to make money from entering into a financing arrangement with a family member.

Parents helping their children should also carefully consider whether they want to tell their other children, if there are any, about the loan. That becomes an even thornier question when money is being loaned between grandparents and grandchildren or aunts and uncles and their niece or nephew, Ekoniak points out.