Moving in together: the money setup for unmarried couples

Moving in together is a financial merger that the law barely recognizes. Married couples get a default legal framework — shared property rules, automatic inheritance, the right to make decisions for each other. Unmarried couples get an apartment and a lease. Everything the marriage license would have handled automatically, you now have to build on purpose, and the couples who skip that work are the ones who discover, during a breakup or a hospital visit, exactly which protections they never had.

What cohabiting does — and doesn't — give you

The core thing to internalize is that living together, however long, usually creates no automatic financial rights between you. A handful of states still recognize common-law marriage under narrow conditions, but most do not, and moving in never triggers it by itself. That means no automatic claim on each other's income or assets, no right to inherit without a will, no authority to make medical or financial decisions for a partner who's incapacitated, and no tax filing status to share. None of this is a reason not to move in. It's a reason to replace the missing defaults with documents you choose.

The account structure that keeps it fair

• Keep your individual accounts. Cohabiting is not the moment to close them — your credit, your paycheck, and your savings stay yours, and staying titled to you keeps them legally clean if you split.
• Open one joint account for shared costs only. Rent, utilities, groceries, shared subscriptions — fund it by an agreed formula and pay shared bills from it, so nobody is tracking who covered the internet this month.
• Split proportionally if incomes differ. A partner earning $40,000 and one earning $80,000 splitting rent 50/50 leaves the lower earner squeezed; contributing the same percentage of income keeps the sacrifice symmetric.
• Keep big purchases documented. If you buy furniture, a car, or a pet together, note who paid what — the receipts are the only record of ownership you'll have.

The documents that replace the marriage defaults

Because the law won't do it for you, a short stack of documents does the work a marriage license otherwise would. A cohabitation agreement — a written contract covering how you'll split expenses, what happens to jointly bought property if you separate, and who keeps the apartment — is the unmarried couple's version of a prenup, and it's most valuable precisely because you draft it while you still like each other. Durable powers of attorney for finances and healthcare, plus a HIPAA authorization, let your partner act for you in a crisis; without them, a hospital may turn to your parents or siblings instead of the person you live with. And if you want your partner to inherit anything, a will or beneficiary designation is mandatory — intestacy laws pass everything to blood relatives and give an unmarried partner nothing.

Renters insurance and the shared-life risks

Two people, one apartment, one set of stuff — but renters insurance doesn't automatically cover both partners. Most policies only cover the named policyholder and relatives, so an unmarried partner's belongings may be uncovered unless they're added or carry their own policy. It's usually cheap to fix (some insurers allow adding a partner; otherwise each buys a $12–25/month policy). While you're at it, name each other as beneficiaries anywhere you intend to — retirement accounts, life insurance if you have it — because those designations, not your relationship, decide who receives the money.

The bottom line

Living together merges your daily life without merging your legal protections, so build the protections yourself: keep individual accounts, share one joint account for shared costs on a proportional split, document who owns what, and sign the powers of attorney and will that a marriage would have made automatic. None of it is unromantic — it's the same act of care a marriage license performs, just done by hand. Do it at move-in, and the paperwork quietly protects both of you whether the relationship lasts a year or a lifetime.