Signing a relationship agreement before marriage is not pessimistic. Doing it before you even get engaged is the smartest financial decision a couple can make in 2025.

That statement makes people uncomfortable. Good. Because the discomfort of signing one document together is nothing compared to losing half your savings, your dog, or your security deposit in a dispute that a single page of paperwork could have prevented.

Here is what nobody tells you: the law was not built for the way most people live now. Roughly 17 million Americans are currently living with a romantic partner outside of marriage, according to a 2023 Pew Research Center survey. The legal system, in most states, treats those relationships as barely existing. When things go wrong, the courthouse does not care how long you were together, how much you loved each other, or whose name is on the Spotify account.

This is the misconception that costs people the most. Living together, even for years, does not automatically grant either partner property rights, inheritance rights, or financial protections in the majority of U.S. states. Common-law marriage is only recognized in a handful of states, and the requirements to qualify are stricter than most couples realize.

A 2022 report from the American Bar Association highlighted a sharp rise in cohabitation-related property disputes, with family law attorneys reporting a 37% increase in cases involving unmarried partners fighting over jointly occupied homes. These are not divorces. Not married couples squaring off in court. These are people who shared beds, bank accounts, and leases with no legal framework to fall back on.

Think about that for a second. Years of shared groceries, shared rent, shared everything. Then one conversation goes wrong and a judge looks at the paperwork and sees two strangers.

2. The “We’ll Work It Out” Assumption Is Where Money Goes to Die

Take Marcus and Dana. Not their real names, but their situation is completely real. Six years together. She financed his IT certification program, roughly $14,000 out of pocket, because they were building a future. He paid rent in cash every month while the lease sat in her name only. When they split at 34 and 31, none of it was on paper.

He could not prove his rental contributions. Legally, he was a guest. She could not recover a dollar of the certification investment. Legally, it was a gift. Marcus moved back to his brother’s couch. Dana changed the locks and cried for a month. Neither of them won.

The ex who kept the receipts wins. That’s the uncomfortable reality of how cohabitation disputes actually resolve.

So here’s the real question: think about the last big financial move you made with your partner. Is any of it documented?

Warning: “We trust each other” is not a legal defense. Courts decide based on documentation, not relationship history. If it isn’t written down, it functionally did not happen.

3. Shared Property Without a Written Agreement Is a Lawsuit Waiting to Happen

When a couple buys furniture together, adopts a pet together, or contributes to a shared savings goal, there is an invisible ownership question attached to every single item. Most couples never answer it. When the relationship ends, those unanswered questions become arguments, and sometimes litigation.

Palimony claims, where one partner sues another for financial support after a long-term cohabiting relationship ends, are increasingly common. California, New Jersey, and Illinois have the most developed case law here, but attorneys in nearly every state report fielding more of these inquiries each year.

A written property list, created together, costs nothing and takes less than an hour. It does not require an attorney to draft. It requires two people sitting down, being honest, and writing things down. That list becomes the evidence neither Marcus nor Dana had.

Action Step: Tonight, open a shared document with your partner and list every item over $200 that you’ve purchased together or that one person contributed to significantly. Date it. Both sign it. That’s your starting point.

4. “Prenup” Is the Wrong Word. That’s Why You’re Not Getting One.

Lawyers stopped calling it a prenup. Now it’s a cohabitation agreement, sometimes called a no-nup, and it does the exact same job. The name change matters because it removes the marriage assumption entirely. This is a document for two people who are building a life together, full stop, regardless of whether a wedding is part of the plan.

Cohabitation agreements can cover property division, financial contributions, pet custody, and debt responsibility. They can be updated. They are not permanent. And according to a 2023 survey conducted by the American Academy of Matrimonial Lawyers, 62% of member attorneys reported an increase in clients requesting cohabitation agreements specifically among couples aged 25 to 40 who had no immediate plans to marry.

That number is going up because people are watching their friends get wrecked in court and deciding they’d rather have a slightly awkward conversation over dinner.

Did You Know: A basic cohabitation agreement can be drafted by a family law attorney for as little as $300 to $500 in most states. Some legal aid organizations offer them for free to qualifying couples.

5. You Don’t Know How to Start the Conversation. Here’s a Script.

Who brings up legal agreements over pasta? Nobody, until they have to. But here is what nobody tells you: the couples who have this conversation early are not the unromantic ones. They’re the ones who trust each other enough to be honest about money, about future plans, about what happens if things don’t go the way they hope.

If you’re reading this at 2am wondering what would happen if your relationship ended tomorrow, this part is for you.

You don’t need to frame it as a legal document. You can open with something like this:

“Hey, I’ve been thinking about how much we’ve built together, and I want to make sure we’re both protected if life ever throws something unexpected at us. I read something this week about cohabitation agreements and I think it’s worth a conversation. Not because I’m worried about us, but because I care about us.”

That’s it. That’s the whole opening move. It positions the agreement as an act of care, not suspicion. Because that’s exactly what it is.

If your partner’s immediate reaction is defensiveness or dismissal, that reaction is also information worth having.

Pro Tip: Have this conversation in a neutral moment, not after a fight or a financial stress event. Timing matters more than the exact words.

So if you split tomorrow, what exactly is in writing between you two? Not as a hypothetical. Right now, today. If the answer is nothing, then you’re not protected by love. You’re just unprotected.

It is messier than the advice columns suggest. Romantic love and legal clarity are not opposites. They’re both forms of respect. The couples who figure that out early are not less romantic. They’re just less likely to end up like Marcus and Dana.

Your Next 3 Steps

Step 1: Pull up your state’s cohabitation rights on NOLO.com tonight. Search your state name plus “cohabitation rights” or “unmarried partner rights.” Takes 10 minutes. Costs nothing. You’ll know within one read whether your state offers any default protections or leaves you completely exposed.

Step 2: This week, open a shared note or document with your partner and write down every significant financial contribution either of you has made to the relationship. Shared purchases, loans between partners, rent paid toward a lease in one person’s name. Date it. Both of you add a typed acknowledgment at the bottom. This is not a legal document yet, but it’s evidence, and evidence is what matters if things ever go sideways.

Step 3: Contact one family law attorney for a free 15-minute consultation and ask specifically about a cohabitation agreement for your situation. Many attorneys offer this call at no charge. Come with two questions: what would a basic agreement cover in your state, and what would it cost to draft one. You’re not committing to anything. You’re just getting informed, and that 15 minutes could be worth more than you know.