Moving in together

Decide together, on purpose, and talk before you pack. It's surprisingly easy to drift in, via the spare key, then the second toothbrush, then somehow a shared sofa. In a national sample of cohabiting people, 66% said they had slid into their living arrangements rather than decided¹.

Start with the big conversation. What does living together mean to each of you? How committed are you, and where do you see this going? Clearly shared goals and commitment are linked with more successful cohabitation¹. Living together can also make a relationship harder to end, so it helps to be candid about what might keep you together¹. It can feel gloomy, but it's also recommended to talk about an "exit strategy" in case it isn't working out¹.

Then have the money chat, ideally before the move. Get to know each other's attitudes to money and your short- and long-term goals. You don't need everything figured out; just start talking². Work out what you can afford and agree the ground rules before you move, not after².

• Write it down. Note who pays what, and keep a simple shared budget for groceries, transport and other household costs. It shows your combined expenses and helps avoid misunderstandings³.
• Check the names. If you both sign a rental lease, you're both responsible for the rent³. Agree whose names go on the lease and on each bill, deliberately.
• Pick a system. Couples who pool all their money tend to have fewer money clashes, though that's a pattern, not a rule for every couple⁴.

One caution: think hard before putting your name to, or guaranteeing, a loan that's only for your partner. If things go wrong, you could be left repaying all of it³. For your own situation, ask a qualified adviser.

No single age or length of time is the right one. How a couple gets to a milestone, by deciding together or by sliding, may matter more than any timetable.

Take moving in before marriage. Among married adults, couples who moved in only after getting engaged did not differ significantly from couples who waited until marriage. That points to any extra risk being linked with moving in before a shared commitment to marry, rather than with living together itself⁵. The age at which a couple first lived together also explained a substantial part of the higher risk of marital breakup among those who lived together first⁶. And a simple yes/no measure of living together before marriage was not associated with marital instability in another analysis⁷. In that analysis, among people who cohabited, being engaged or having definite plans to marry beforehand was linked with lower instability for women but not for men⁷. That's an average, not a verdict on any one couple.

One idea is that moving in creates inertia, so some couples end up married who otherwise wouldn't have, staying together whatever the quality or fit⁸. That's a reason to check each milestone is a choice you're both making, not just the easier or expected next step.

On children, the only finding is narrow: among college-educated women, delaying parenthood was linked with greater career attainment and a higher chance of finding a high-quality mate to raise children with⁹. It doesn't tell couples in general when to start a family.

Treat all of this as patterns in groups, mostly from observational, US-based research, not a prediction for you two. Talk about what each of you wants and where you see things going, and come back to it as work, money and plans for children change.