Cohabitation agreements in the UK, the contract that fills the legal gap

Around 3.6 million couples in the UK cohabit without marrying or entering a civil partnership, according to the Office for National Statistics. That number has more than doubled since 1996. The law has not kept pace, and cohabitants have no automatic rights to property, pension, or inheritance if the relationship ends or one partner dies. A cohabitation agreement is the most direct way to address that.

What a cohabitation agreement is

A cohabitation agreement (sometimes called a living together agreement) is a written contract between two adults who live together. It typically covers:

• How property is owned and what happens to it if you separate
• How household bills, the mortgage or rent, and shared expenses are split
• What happens to assets bought during the relationship
• Pension and savings intentions
• Arrangements for children where relevant
• How disputes are resolved

It is a contract under ordinary contract law. Unlike a prenup, there are no specific procedural requirements set out in statute. To be enforceable, the standard contract law tests apply: both parties must intend to create legal relations, both must enter freely without duress, there must be consideration, and the terms must be sufficiently certain.

Why it matters more than people realise

Without an agreement, disputes between separating cohabitants fall back on the law of trusts. The Supreme Court cases of Stack v Dowden [2007] UKHL 17 and Jones v Kernott [2011] UKSC 53 govern how beneficial interests in a shared home are decided when there is no clear written record. The litigation is slow, expensive, and unpredictable. A signed agreement, with a Declaration of Trust over the property if one of you is on the title alone, removes most of that risk.

What a cohabitation agreement does not do

It does not give you the automatic rights of a married couple. It does not extend pension sharing on separation. It does not change the rules of intestacy if a partner dies without a will. For those, you still need separate steps (wills, pension nominations, lasting powers of attorney).

What it does do is give you a clear, mutually acknowledged record of what you have both agreed. In any later disagreement, in mediation, or in court, it is a strong evidential anchor.

The case for writing it down early

The Law Commission recommended a statutory framework for cohabitants in 2007. The Women and Equalities Committee echoed that recommendation in 2022. Neither has yet become law. Until it does, the protection cohabiting couples have is the protection they create for themselves. A short, plainly written, signed agreement does most of the work, and it is the foundation that every other practical document (will, Declaration of Trust, pension nomination) sits on.