Cohabitation agreements: what they are, and whether you actually need one

What a cohabitation agreement is

A cohabitation agreement (sometimes called a living together agreement) is a written contract between two people who live together but aren't married or in a civil partnership. It sets out, in advance, how you'll handle money and property — both while you're together and if you ever separate.

Because unmarried couples have no automatic legal framework to fall back on, a cohabitation agreement effectively builds your own. Instead of a court trying to reconstruct your intentions years later from bank statements and half-remembered conversations, the agreement states them plainly, signed by both of you, at a time when you were getting along.

What it typically covers

• The home: who owns what share, what happens to the deposit if you sell or separate, and how mortgage payments count
• Bills and living costs: how day-to-day expenses are split, and whether that affects ownership
• Savings and debts: what's joint, what's separate, and what happens to each on separation
• Belongings: furniture, cars, pets — the things that cause disproportionate arguments later
• What happens if you separate: who moves out, notice periods, how the practical unwinding works

Is it legally binding?

Broadly yes, if done properly — this is contract law, not family law. Courts in England and Wales will generally uphold a cohabitation agreement where both partners entered it freely, with a reasonable understanding of what they were signing, and where it was executed properly. The strongest agreements share three features: full financial disclosure by both partners, each partner taking independent legal advice (or at least having a genuine opportunity to), and the agreement being kept up to date as circumstances change — a new house, a child, a big inheritance.

Cohabitation agreement vs. Declaration of Trust

These get confused constantly. A Declaration of Trust is narrower: a legal document that fixes the ownership shares of a specific property — often done when buying, especially with unequal deposits. A cohabitation agreement is broader, covering your whole financial life together, and can incorporate or sit alongside a Declaration of Trust. If you're buying a home with unequal contributions, many couples do both: the Declaration of Trust to nail down the property shares, and the cohabitation agreement for everything else.

What it costs

A solicitor-drafted cohabitation agreement typically runs from a few hundred pounds to over a thousand, depending on complexity and whether both partners take independent advice. Template services offer a much cheaper starting point — reasonable for simple situations, though a template without advice carries more risk of being challenged later. As a rule of thumb: the more unequal your finances, the more a properly advised agreement is worth.

When you should seriously consider one

• You're buying a home together with unequal deposits
• One of you owns the home and the other is moving in
• One of you earns significantly more, or has significantly more assets
• Either of you has children from a previous relationship
• One of you is giving something up to move in — a job, a city, a tenancy

The groundwork you can do for free, today

Whatever route you take, every cohabitation agreement starts from the same raw material: an honest picture of who has put in what. Keeping that record as you go makes the agreement cheaper to draft, harder to dispute, and much easier to keep up to date.