By Sital Somaiya, Founder and Solicitor. Last reviewed 14 October 2026.
Key points
- A cohabitation agreement records how an unmarried couple own and pay for things, and what happens if they separate.
- It can be enforced as a contract if it is properly made, with independent advice and full financial disclosure.
- It cannot oust the court on arrangements or support for children.
- Nothing in the law has changed for cohabiting couples, so it remains the main way to protect yourselves.
A cohabitation agreement is a written agreement between two people who live together, or are about to, setting out how they own and pay for things and what should happen if they separate. For unmarried couples it is the single most useful document they can sign, because the law gives them so little protection by default.
There is no such thing as common law marriage in England and Wales. Our guide to your rights after years together explains what the law does and does not give you.
In this guide
- What happens if you do not have one
- What a cohabitation agreement usually covers
- Is a cohabitation agreement legally binding?
- When an agreement may not be upheld
- Cohabitation agreement or declaration of trust?
- How to make one: step by step
- What if the law changes?
- Frequently asked questions
- Talk to us
What happens if you do not have one
If you separate without an agreement and cannot agree who gets what, a dispute about the home is decided under property law, not family law. The court asks who owns what, not who needs what. That often means a TOLATA claim, which is evidence-heavy, slow and expensive, because the court has to work out what you both intended, often years after the event. A cohabitation agreement removes most of that guesswork.
What a cohabitation agreement usually covers
| Area | What the agreement records |
|---|---|
| The home | Who owns it and in what shares, who paid the deposit, and what happens if you separate |
| Mortgage and rent | Who pays what, and whether payments change your shares over time |
| Bills and household costs | How day-to-day costs are split, and how joint accounts are run |
| Savings and investments | What stays separate and what is shared |
| Debts | Whether debts in one name are shared, and how joint debts are dealt with |
| Belongings, cars and pets | Who keeps what |
| Separation | How long one of you can stay in the home, and how it is sold or bought out |
| Death | A reminder that you each need a will, because the agreement does not replace one |
You can record arrangements for children, but these are always subject to the court. Neither of you can sign away a child’s right to financial support, and the court will decide arrangements for children by what is best for them.
Is a cohabitation agreement legally binding?
A cohabitation agreement can be enforced as a contract if it is properly made. The courts look at whether you both entered into it freely, understood what you were signing, and had the information you needed. To give it the best chance of being upheld:
- Each take independent legal advice from separate solicitors
- Give each other full financial disclosure, so neither of you can later say you did not know the other’s position
- Sign it as a deed, which also meets the legal formalities for declaring how you own land
- Sign it well before any major event, not on the day you exchange contracts on a house
- Review it when your circumstances change, for example having a child, buying a new home or a big change in income
When an agreement may not be upheld
An agreement is weaker if one of you was pressured into signing, if important financial information was hidden, or if circumstances have changed so much that it no longer reflects what you intended. The arrival of a child is the most common example. A review clause, which commits you to looking at the agreement again after certain events, helps keep it valid.
Cohabitation agreement or declaration of trust?
A declaration of trust records how you own one specific property and in what shares. A cohabitation agreement is wider and covers your finances and arrangements generally. Couples buying together often have both: a declaration of trust for the home, and a cohabitation agreement for everything else. Our conveyancing and family teams can do both at the time of purchase.
How to make one: step by step
- Talk it through together first, so you know what each of you wants
- Instruct separate solicitors, one each
- Exchange financial information, including income, savings, debts and contributions to the home
- Agree the terms through your solicitors
- Sign it as a deed, with each signature witnessed
- Keep it safe, alongside your wills and property documents, and diarise a review
What if the law changes?
The Government consulted in 2026 on a new scheme of financial claims for cohabiting couples. The consultation closed on 14 August 2026, no Bill has been introduced, and nothing has changed in the law. The proposals included letting couples opt out of any new scheme by written agreement, subject to safeguards. If a scheme is introduced, existing agreements may need to be reviewed. Our guide to cohabitation law reform covers the proposals.
An example
Amira and Tom are buying a flat in Gidea Park. Amira is putting in £40,000 from an inheritance and Tom £10,000. They will pay the mortgage equally. Without an agreement, as joint owners the starting point would be equal shares. Their cohabitation agreement and declaration of trust record that Amira’s extra £30,000 comes back to her first on a sale, with the rest divided equally. It also covers who stays in the flat if they split, and how long the other has to be bought out.
This is an illustrative example, not a real case.
Frequently asked questions
Do we need a cohabitation agreement if we own the house jointly?
Usually, yes. Joint ownership tells you the starting point for the house, but not who paid what, how the mortgage is split, what happens to savings or debts, or how the house is dealt with if you separate.
Can we write our own cohabitation agreement?
You can, but a home-made agreement is easier to challenge, particularly if neither of you took advice or disclosed your finances. The cost of doing it properly is small compared with a contested property dispute.
Do we each need our own solicitor?
It is strongly recommended. One solicitor cannot advise both of you, and independent advice is one of the main things a court looks at if the agreement is ever challenged.
Is a cohabitation agreement the same as a prenup?
They do a similar job for different couples. A prenuptial agreement is made before marriage and the court can depart from it on divorce. A cohabitation agreement is for unmarried couples and is treated as a contract.
When is the best time to sign one?
Before you buy or move in together. It is still worth making one later, at any point while you are getting on well.
Sources
- Law of Property Act 1925, section 53, legislation.gov.uk
- Money and property when a relationship ends, GOV.UK
Talk to us
Signature Law drafts cohabitation agreements and declarations of trust for couples in Romford, across Essex and in East London, and can advise either partner. See our cohabitation solicitors page and our fees.
Request a callback, or call 01708 398 851.
