Cohabitation Agreement UK: Legal Effect, What to Include, and Why You Also Need a Will

Updated: 17 May 2026 • Reading time: 8 min

More than 3.6 million couples in England and Wales live together without being married or in a civil partnership. Despite widespread belief, there is no such thing as “common law marriage” in English law. Cohabiting couples have almost no automatic legal rights over each other’s property, income, or estate. A cohabitation agreement cannot fix everything — but combined with a will, it is the most important legal step an unmarried couple can take.

What Is a Cohabitation Agreement?

A cohabitation agreement (also called a living-together agreement or cohabitation contract) is a private legal contract between two unmarried partners that records:

Who owns what — the family home, savings, vehicles, personal property
How shared costs (mortgage, bills, rent) are divided
What happens to assets if the relationship ends or if one partner dies
How any dispute about property will be resolved

It does not create a marriage or civil partnership, and it cannot give a cohabiting partner the same rights as a spouse. It is a snapshot of the financial deal the couple has agreed — recorded clearly so there is no ambiguity later.

Is a Cohabitation Agreement Legally Binding?

Courts in England and Wales treat a cohabitation agreement as an ordinary commercial contract. The agreement is enforceable if:

Both parties freely agreed to its terms
Both received independent legal advice before signing
The terms are clear, certain, and not contrary to public policy
It is executed as a deed (signed, witnessed, and delivered)

An agreement signed without independent advice, under pressure, or using a generic online template without legal review is much easier to challenge. Unlike prenuptial agreements (which now carry a strong but rebuttable presumption of enforcement under Radmacher v Granatino [2010]), cohabitation agreements are pure contract — there is no family law discretion to “do justice” that a court can invoke to override clear contractual terms.

What to Include

The Family Home

Whether the property is jointly owned or in one name, the agreement should state:

The beneficial ownership shares (50/50, or another split)
How the deposit was funded and whether this affects the split
How mortgage payments, renovations, and improvements are treated
The mechanism on separation — right to buy out the other’s share, forced sale, or first refusal
Whether either partner has a right to remain in the property after separation (relevant if children live there)

Finances and Personal Property

How household bills and living costs are split
Whether joint bank accounts are held — and how they are divided on separation
Who owns savings accumulated before or during the relationship
Ownership of major personal assets: cars, jewellery, business interests

Children

A cohabitation agreement can record intentions about financial support for children, but it cannot oust the jurisdiction of the courts over child maintenance (Child Support Act 1991) or child arrangements. For children, a will is also essential — appointing a guardian for minor children is only possible in a will, not a cohabitation agreement.

What a Cohabitation Agreement Cannot Do

A cohabitation agreement cannot:

Override the intestacy rules on death. It is a contract governing lifetime and separation rights, not succession.
Guarantee a legacy. A promise to “make a will leaving the house to you” is contractually unenforceable — wills can be changed at any time and a court will not force a testator to maintain a particular will.
Give a partner pension rights. Expression-of-wishes nominations on pensions are decided by pension trustees — a contract between two individuals cannot bind them.
Create inheritance tax spouse exemption. Only spouses and civil partners benefit from the unlimited IHT spouse exemption. An unmarried partner inheriting under a will pays IHT on amounts above £325,000 (the nil-rate band).

Why Every Cohabiting Couple Also Needs a Will

English intestacy law (Administration of Estates Act 1925) does not recognise cohabiting partners, however long the relationship. If one partner dies without a will, the other receives nothing from the estate. The estate passes to:

Biological or legally adopted children (or their descendants)
Parents
Siblings
…and so on down the statutory order

A surviving cohabiting partner can claim under the Inheritance (Provision for Family and Dependants) Act 1975 if they lived with the deceased for at least two years immediately before death — but such claims are expensive, slow (12–18 months in court), and uncertain. Courts award only “reasonable financial provision”, not necessarily the share the partner would have received under a will.

A will solves this entirely: it lets each partner leave their estate to the other, appoint guardians for children, set up trusts for minor beneficiaries, and nominate executors who will deal with the estate efficiently.

Practical Checklist for Cohabiting Couples

Check how your property is legally held — joint tenants (survivorship) or tenants in common (share passes under will/intestacy)
Draft a cohabitation agreement with a solicitor covering the home, finances, and separation arrangements
Ensure both partners receive independent legal advice and sign as a deed
Write mirror wills leaving your estates to each other (and naming guardians for children)
Update pension expression-of-wishes forms to nominate your partner
Consider a life insurance policy written in trust to provide for your partner outside your estate
Review both the agreement and your wills after any major life event: new child, new property, significant change in income

Frequently Asked Questions

Is a cohabitation agreement legally binding in England and Wales?

A cohabitation agreement is a private contract between unmarried partners and is generally enforceable as a contract under English law, provided the usual contractual requirements are met: offer and acceptance, intention to create legal relations, and consideration. Courts have recognised cohabitation agreements as binding contracts (see Sutton v Mishcon de Reya [2003] for background). To maximise enforceability: have the agreement drawn up by a solicitor; ensure both parties take independent legal advice and sign a certificate confirming they received it; execute it as a deed (signed, witnessed, and delivered) rather than a simple contract. An agreement signed without independent advice or under duress is vulnerable to challenge. Unlike prenuptial agreements (which courts 'should' follow under Radmacher v Granatino [2010] subject to fairness), cohabitation agreements are pure contract — courts apply ordinary contract law rather than family law discretion.

What should a cohabitation agreement include?

A well-drafted cohabitation agreement should cover: (1) Property ownership — whether the family home is owned jointly (and in what shares) or by one partner only, and what happens to equity on separation or death; (2) Contributions to the property — mortgage payments, deposit payments, and improvement costs, and whether these create a beneficial interest; (3) Day-to-day finances — how household bills, living costs, and joint accounts are managed; (4) Personal property — who owns furniture, vehicles, savings accounts, and other assets acquired before or during the relationship; (5) Children — financial arrangements for any children of the relationship (although courts have a separate statutory jurisdiction over child maintenance and child arrangements that cannot be ousted by contract); (6) Separation provisions — how assets are divided if the relationship ends, including a mechanism for valuing and transferring property; (7) Review clause — the agreement should be reviewed after major life events such as the birth of a child, a significant change in income, or buying a new property.

Does a cohabitation agreement replace a will?

No. A cohabitation agreement operates during the relationship and on separation — it does not govern what happens on death. On death, your estate passes under your will (or intestacy if you have none). A cohabitation agreement cannot override the intestacy rules or substitute for a valid will. Without a will, an unmarried partner has no automatic right to inherit under English intestacy law: they receive nothing, regardless of how long the relationship lasted or how financially dependent they were. A cohabitation agreement might record that Partner A 'will make a will leaving the property to Partner B', but this is unenforceable as a promise — a will can be changed at any time, and courts will not enforce a promise to make or maintain a particular will (subject to the narrow doctrine of mutual wills). Both a cohabitation agreement and a will are needed.

Can cohabiting partners inherit each other's estate without a will?

Under current English intestacy law (Administration of Estates Act 1925 as amended), an unmarried cohabiting partner inherits nothing if their partner dies intestate — regardless of how long they lived together. The intestacy order does not include cohabiting partners. This is the 'common law marriage myth': there is no such legal status in England and Wales. Without a will the estate passes to: the deceased's children (or remoter descendants); then parents; then siblings; and so on down the statutory list — but never to an unmarried partner. A cohabiting partner may be able to make a claim under the Inheritance (Provision for Family and Dependants) Act 1975 as a person who lived in the same household as the deceased for the whole of the two years ending immediately before death (s.1(1)(ba)), but this is expensive, uncertain, and can take years. A valid will is the only reliable way to protect a cohabiting partner.

What happens to shared property if a cohabiting couple separates?

Without a cohabitation agreement, disputes over shared property are resolved under trust law — specifically the law of resulting and constructive trusts under the Trusts of Land and Appointment of Trustees Act 1996 (TLATA). Courts examine: the legal title (whose name is on the register); any express declaration of trust; and, if silent, the common intention of the parties at the time of acquisition or later — inferred from financial contributions and conduct (Stack v Dowden [2007] UKHL 17; Jones v Kernott [2011] UKSC 53). These cases are expensive and unpredictable. A cohabitation agreement eliminates this uncertainty by recording agreed ownership shares, contributions, and the mechanism for division on separation. If the home is in joint names as tenants in common, the agreement should state the percentage shares and how a sale or buyout is triggered.

How much does a cohabitation agreement cost and do I need a solicitor?

A solicitor-drafted cohabitation agreement for a straightforward cohabiting couple (shared home, joint finances) typically costs £500–£1,500 per partner (including independent legal advice). More complex arrangements — significant pre-owned assets, business interests, children from previous relationships — cost more. Online template agreements are cheaper (£50–£200) but carry significant risk: a generic template may not reflect your specific property ownership structure, may not be executed as a deed, and neither party will have received independent legal advice, weakening enforceability. For most cohabiting couples who own property together, the cost of a properly drawn agreement is modest compared to the potential loss of tens or hundreds of thousands of pounds in a disputed separation. The agreement should be updated whenever your circumstances materially change.

Protect Your Partner — Write a Will Today

A cohabitation agreement records what you own. A will determines who inherits it. WillSafe helps cohabiting couples write legally valid wills quickly, without solicitor fees.

Get started with WillSafe