It’s more common than ever for unmarried romantic partners to live together before — or without ever — getting married. In fact, the number of U.S. adults in cohabiting relationships rose 29 percent from 2007 to 2016, totaling 18 million people, according to the Pew Research Center.

Living with your significant other can come with numerous advantages — you can save money on rent and ultimately experience a more intimate relationship. However, unmarried couples living under the same roof face some unique financial challenges. Should you split expenses evenly, or in proportion to your income? How do you invest and save for a future together? And what about taxes?

Here are some personal finance issues you should consider before moving in with your partner.

Long-Term Wealth Might Not Add Up

Saving money probably isn’t the main reason you’re moving in with your significant other. But let’s get real: Getting a place together means spending less on housing and sharing the expenses of groceries, utilities and even traveling. Those savings can add up — fast.

However, research shows that living together might benefit traditional spouses more than it does unmarried couples. A study presented at the 2017 Financial Planning Association Conference looked at data from more than 5,100 adults and found that cohabiters tend to have a lower net worth and financial asset accumulation than married people. Plan ahead the ways that you’ll capture the savings from living with your partner and reinvest them in your own future to stay on track with your financial goals.

Singles Could See Lower Taxes

Couples who’ve put a ring on it might accumulate more long-term wealth, but maintaining that single status comes with its own tangible benefit: Tax savings.

“If [couples who are cohabiting] live in a high tax state or have student loans, they are probably better off not getting married,” said Beth Logan, enrolled agent and a lead tax advisor at Kozlog Tax Advisers.

You can deduct up to $2,500 in student loan interest payments each year, per return. That means if you file together, you can only take up to $2,500, whereas if you file separately you and your partner can each take the full amount, Logan explained.

Another potential win for cohabiting singles versus married couples is the new limit on state and local tax (SALT) deductions. Starting in the 2018 tax year, the government began limiting how much SALT people can deduct from their federal taxable income to $10,000 for both individuals and married filers. That means that dual-income married couples will only be able to deduct $10,000 total, whereas cohabiting singles can deduct a total of $20,000 ($10,000 per person).

“Every situation is different and people with significant differences may be better off married,” added Logan.

Combining Finances Comes With Caveats

Given the discrepancy in accumulated wealth between married and cohabiting couples, is it a smart move to open up a shared retirement account when you sign a lease with your unmarried partner?

Experts say you might want to think twice about that. Married couples going through a divorce will have the help of lawyers and courts to divvy up mutual investments, whereas cohabiting couples who break up will be left in a much messier financial situation with no guarantees about who gets what. It’s a better idea to consider investing a solo activity, said Ilene Davis, a certified financial planner who has been in an unmarried relationship for 26 years.

“Put money aside to protect yourself and your future with an IRA and a 401k plan,” said Davis. “Each of you should figure out what you need for your own finances, and if you wish, you can make the other person the beneficiary of those accounts.”

But what about opening a joint bank account to pay for shared expenses, like utilities?

Ultimately, couples should do what’s right for them. However, keep in mind that opening a joint account could leave you vulnerable to your partner’s financial whims without any of the legal protections afforded to married couples.

“If you’re a saver and your partner’s a spender, you’ll run into money problems,” said Davis.

Fortunately, couples no longer need joint bank accounts to pay bills. New peer-to-peer payment systems (like Venmo and Zelle) make it easy for you to send money back and forth instantly.

Dreaming of buying a home, boat, car or other major asset with your sweetheart before marriage? If you’re both contributing to the cost, make sure you’re both on the title or deed. That way, you can claim at least partial ownership if the relationship ends.

Agreements Protect Couples

Spending time negotiating financial responsibilities probably isn’t your idea of a romantic Friday night. However, this stuff doesn’t work itself out on its own. Nailing down a budget can take away a lot of stress in your relationship — and keep your finances in order.

List all of your shared expenses to figure out what you’re responsible for in total. Then, decide how you’re going to divvy up those bills.

“Are you going to split them equally or based on a percentage of your income? If that’s not decided up front, it’s going to lead to problems,” said Davis.

This is also a good time to create a parenting agreement if you’re planning to have kids together, or if one or both of you already has a child from a previous partnership.

While heartbreaking to think about, splitting up can mess up both your finances. Can one of you afford to take over the full rent payment if the other moves out? Who gets which pieces of furniture? And what will happen to any pets (and the cost of their care)? Making decisions about these key issues ahead of time could give you both peace of mind and protect your finances if cohabitation doesn’t work out.

Moving in together is often a heart-driven decision rooted in a desire to spend more time together. With that being said, it’s important to remember that shared expenses and finances don’t come with the legal protections that married couples get. Put your relationship on a solid foundation by making sure you’re both clear on expenses. But continue pursuing major financial goals on your own — just in case.