Should you and your partner combine finances? 3 common money mistakes — and how to talk about them

Talking about money or financial topics can be a conversational minefield. Even asking someone what they do for a living, if done the wrong way, may come across as crass or opportunistic. But the motherlode of awkward money questions?

Try: "Are you and Bob combining your bank accounts after you get married?"

Deciding how love will affect money (and vice versa) is private, uncomfortable territory and especially ill-advised in mixed company, since people's beliefs reflect personal preferences that might be colored by gendered expectations, heteronormativity or other biases.

Expectations vary, and older Americans — who might remember a time before laws protected a woman's financial independence, for example — are more likely to mix money. A 2016 survey by TD Bank found that 31% of coupled adults younger than 35 said they keep their money completely separate from their partner's, while only 8% of people 55 or older said the same.

Meanwhile, 64% of those older respondents said they "combine everything," but just 37% of millennials said the same.

Now, there are certainly benefits to sharing finances with a partner, especially once you've tied the knot. There's only one set of tax forms to fill out, for one, to say nothing of the emotional benefits — relationships are built on trust, after all. And sure, it might seem more romantic or "traditional" for partners in it for the long haul to merge their money.

But there are also many potential reasons why a couple might decide to keep finances partially or completely separate. Maybe someone in the relationship has a kid from a previous marriage or a fat inheritance on the way. Perhaps one of you is just really bad at spending. Sometimes separate bank accounts make a lot of sense, helping you split expenses more equitably, protect your nest egg and even preserve your relationship.

In short, there's no one "right way" to manage money as a couple — though there might be several "wrong ways" or, at least, financial pitfalls you might want to avoid.

Are you and your partner thinking about sharing bank accounts or otherwise splitting your finances? Here are three big mistakes to watch out for, and how to overcome them.

1. Thinking you should combine finances all at once 

Many couples treat merging their money as an "all or nothing" kind of endeavor, but that's a mistake, said Erin Lowry, author of Broke Millennial. 

"One of the biggest mistakes couples make is sharing a bank account too early," Lowry said. "If you have an acrimonious breakup, and if you’ve been dumping a lot of income in there, they can just take it and run." 

While many personal finance experts say it's never too early to start talking about money, it's best to take baby steps when it comes to actually merging finances. In fact, more and more couples seem to be taking this route — particularly younger couples, said Derek Zumsteg, a product designer at online bank Simple who designed the company's shared accounts. 

"Most people start out sharing one expense, usually triggered by a life event like moving in together or having a kid," Zumsteg said. "And as their lives get more interconnected, more money goes into that account."

Being smart about dividing expenses ahead of time can create a degree of independence — while also avoiding awkward conversations if the relationship goes south, noted Stefanie O'Connell, a millennial money expert. 

"If you're not married, it can be helpful to decide who purchases what rather than splitting all costs," O'Connell said. "That way, if something does go awry in the future, it's clear what belongs to who. This is especially important as moving in together increasingly becomes an economic decision ... rather than a next-step-in-the-relationship decision."

In other words, if you're simply moving in together to save on rent, it's better to be clear about who's buying the couch, TV or Netflix subscription as opposed to splitting everything 50/50.

2. Keeping financial secrets  

Money problems carry a lot of stigma for those seeking mates: Nearly 21% of people aged 25-35 said they think debt is the biggest dating deal-breaker, according to a survey by student loan refinancer SoFi. 

That might be one reason why, even once you get to the relationship stage, financial deceit-by-omission is more common than it should be. About 5% of respondents to a survey by CreditCards.com reported keeping a money secret from a partner, like a hidden credit card or bank account.

This behavior can be harmful for lots of reasons, including the way it damages trust and how it can lead to shortfalls in your monthly budget. 

But if you discover (or simply suspect) financial dishonesty by a partner, try to be sensitive when you confront them. Since money can make people feel insecure, Lowry often calls the act of sharing finances "getting financially naked." Just like when someone gets naked-naked, you'll want to make them feel safe and supported — so they'll continue to open up in the future.

"A bottle of wine never hurts," Lowry said. "You have to have a poker face on, there can be no crinkling of the nose, no side eyes, no eye-rolling. If you get physically naked in front of someone and they laugh, you’re not gonna wanna do it again."

Timing is also everything, said Shelly-Ann Eweka, a financial planner at TIAA. 

"Handle it in the right moment, Eweka said. "Don’t break your credit score out during Grey’s Anatomy or a baseball game."

If you're having trouble bringing up the topic, try to find a way to make it less personal, said Lonnie Barbach, a couple's therapist who helped design an app to help couples communicate. "Instead of asking to see someone's credit report, ask them about their parents' money habits," Barbach said. That can often "be a window into their own values."

Anther trick you can try? Frame your money conversation ice-breaker as a positive, as opposed to a negative. Rather than lamenting about the fact your most recent date night wasn't easy on the wallet, specify a different restaurant you'd like to go to — because it's romantic and affordable. 

3. Not specifying personal and shared expenses

When you're sharing a life together, it's just as important to get aligned on the little expenses as it is "big-picture" stuff, like how many kids you want to have and when you might want to buy a home. 

For example, what about floss, surge protectors and toilet paper? It's important to determine early on how to divide such expenses in a way that avoids resentment, especially since many individuals have different incomes and priorities.

"I don’t know many couples that are completely equitable and making the same salary," Lowry said. "And it’s becoming more common that the woman is the breadwinner."

Avoiding awkward conversations about shared expenses is one reason why Zumsteg added a feature to send customers a push notification whenever a shared bank account gets used. That transparency, Zumsteg said, removes a lot of the ambiguity around what constitutes shared and personal expenses: "If you’re hesitant to put it on the shared account, you think about why."

But if receiving push notifications every time your partner swipes their debit card seems too invasive, there are other ways to divide expenses. You might, for example, split the bills in proportion to how much each individual contributes to the total household income. So, if you make $60,000 a year and your partner makes $40,000, an equitable arrangement might be splitting the bills 60/40. 

Money problems aren't the most common marital woe, but research suggests that once financial conflicts surface, they tend to linger and hurt relationships more than other issues. 

You and your partner should meet these challenges head-on by having conversations sooner rather than later, when the stakes are likely to be lower.

Finally, if you're still having trouble playing fair when it comes to money once everything's out in the open, remember: There's nothing wrong with bringing in a third party (think: a financial planner) to referee. 

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