Second marriages can bring a special set of financial challenges, and one of those is figuring out what money rules will govern the new blended family.

If the merging families came from different income brackets, they may be used to handling money in different ways, including what kinds of things the parents buy for their children.

But even in couples from similar financial backgrounds, the two parents may have different philosophies on chores, allowances and savings strategy. The rules that were negotiated with the previous spouse may not sit well with the new spouse. And as a single parent, you might have gotten used to making all your own rules, without consulting anyone else, when it comes to family finances.

“There’s a new you now,” says Ellie Kay, author of 15 books and founder of the Heroes at Home financial program for military families. She and her husband of 29 years have a blended family of seven children, now grown. “You’ve got two people coming together to create a new family and a new dynamic.”

[See: 25 Fast Financial Fixes.]

Couples coming to second marriages not only bring individual attitudes toward money, but their ability to trust may have been bruised by a bad first marriage. Plus, either or both parties may bring debts and financial obligations.

“In my mind, a lot of what happens around money … [is] often driven by below-the-surface matters related to fear or trust,” says Ron Deal, director of FamilyLife Blended and co-author of “The Smart Stepfamily Marriage.” “Someone who has already been through a messy divorce has an apprehension about trusting.”

All couples should have serious discussions about money before getting married, but it’s especially important for blended families. It’s also important to meet with a financial planner and discuss how old debt and obligations such as spousal support, child support, student loans and credit card debt incurred with a previous spouse will be handled, plus how children and new spouses will be protected financially.

“You have to do the hard work of stepping back and asking about your values about money,” Deal says. “If you can’t come to terms with that while you’re dating … it’s at least a yellow flashing light. You don’t just barrel down the road and get married.”

Communication is the key, but it’s not always easy to talk about money.

“Communication is one of the most important parts of a blended family,” says Dennis Poncher, founder of Because I Love You (B.I.L.Y.), a network of support group for parents and children. “They don’t know how to talk about it. They turn away from it.”

All families are different, so there is no set of “best practices” about how money should be handled in blended families beyond good and frequent communication about finances. Whether you have one joint bank account or keep two or three accounts matters less than whether the parents agree on a money philosophy and are consistent in applying it.

[See: 7 Deadly Money Sins to Avoid.]

“All these positions have their validity, and couples can be relatively happy with any of these systems,” Deal says. “It is that discussion that finds couple agreement that makes things work. … When people start falling back on ‘it’s my kids’ or ‘my money’ that fosters divisiveness.”

Here are seven tips for managing finances in a blended family.

Keep the parents on the same page. It’s likely that the two families previously operated under different rules on allowances, chores, smartphones and other financial issues. Parents need to discuss all those issues and agree, then present the plan to the children. “Don’t make decisions fly by night,” Kay says. “It’s important to be intentional and purposeful.”

Establish one set of house rules and be consistent. Children of blended families, like all kids, know how to play one parent off the other. “The problem starts at the parents. It doesn’t start with the kids,” Poncher says. “They know which is the marshmallow and which is the authoritarian. … A united front is harder to break through.” It’s important that parents settle any disagreements between themselves and then present a united front to all the children.

Have family meetings. A new family is a change for everyone, and financial rules are likely to change, too. Plus, as kids get older, procedures regarding family finances will need to be updated. Kay and her husband had periodic family meetings, where they explained how things would work in an age-appropriate way, then served pizza and watched a movie. “We tried to make it upbeat,” Kay says. “The kids will catch on to your enthusiasm.”

Work with the co-parents. Children in blended families usually have a second birthparent and may live part time in another household with different rules. When possible, it’s good to discuss financial issues and house rules with your co-parent and try to work together. If one household allows video games and another doesn’t, for example, then the child can be told not to bring his or her video games to the other house. “Co-parenting relationships will dictate whether you have the ability to call up the co-parent and talk about it,” Deal says. “You make your decision for your home, and you stick with that.”

Handle legal issues. Blended families may be paying or receiving child support or spousal support. Plus, wills, trusts and other legal documents need to be updated or created to make sure that assets go to the intended beneficiaries. Having all the proper legal documents in place provides security and clarity for everyone.

[See: 11 Expenses Destroying Your Budget.]

Decide how you’ll celebrate special events. Holidays can be a minefield because everyone believes his or her holiday traditions are best. Discuss early on how gifts and expenses will be handled for the holidays and birthdays.

Don’t forget adult children. You may think you will avoid all these issues if your children are grown. But adult children who come back to Mom or Dad for money can create major problems in a second marriage. You and your spouse should discuss ahead of time when, or if, a son or daughter can move back home or whether you are willing to provide financial help. “You may have one parent who is a perennial helicopter … and another who doesn’t know when the kid can’t make rent,” Kay says. “The two have to come together. Otherwise, they’re fighting each other. … Adult children can torpedo a marriage faster than any other factor.”

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7 Tips for Merging Finances in Blended Families originally appeared on usnews.com