Not Married But Buying a Home Together? Here's the One Thing You Absolutely Must Do

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More couples than ever are buying property together without getting married first. In fact, cohabiting couples are now the fastest-growing family type in the UK — with the number rising from 5.5 million in 2014 to 6.5 million in 2024, according to the Office for National Statistics. That’s roughly one in four couples who live together without a marriage certificate between them.

Buying a home is exciting. It’s a milestone. But for unmarried couples, it also comes with a legal risk that most people simply don’t know about — until it’s too late.

So what’s the one thing you must do before you buy? Get a cohabitation agreement — and make sure your property ownership is structured correctly from day one.

Here’s everything you need to know.

The Myth That Could Cost You Everything

Let’s start with the most dangerous misconception in UK property law: the “common law marriage” myth.

Many people believe that living with a partner for several years — paying the mortgage together, sharing bills, building a life — gives you the same legal rights as a married couple. It doesn’t. Not even close.

In England and Wales, cohabiting couples have no automatic legal rights over each other’s property, savings, or assets if the relationship breaks down. The law doesn’t care how long you’ve been together, how much you’ve contributed, or how intertwined your finances are.

Consider this real-world scenario: Emma and James lived together for 12 years and bought a flat in Emma’s name alone. When they separated, James discovered he had no legal claim to the property — despite contributing to the mortgage and bills for over a decade. Without a cohabitation agreement, years of investment and effort can simply vanish.

This is not a rare edge case. It is the default position under English law.

Why Unmarried Couples Are So Vulnerable When Buying Property

When a married couple separates, the court looks at what’s “fair” and divides assets accordingly — taking into account future housing needs, contributions, and the length of the relationship. The starting point is broadly equal.

For unmarried couples, none of that applies. The law treats cohabitants based purely on legal ownership — who is named on the title deeds, and in what proportion. Fairness is not a relevant factor.

This means:

If the property is in one person’s name, the other may have no legal claim — even if they’ve been paying the mortgage for years.
If you split without a written agreement, disputes over who owns what can end up in court — which is expensive, time-consuming, and deeply stressful.
If one partner dies without a will, the surviving partner has no automatic right to inherit their share of the home. The property could pass to the deceased’s family members instead.

The legal protections available to unmarried couples in England and Wales are, frankly, minimal. Property stays with whoever is named on the title, and there is no guaranteed financial support on separation.

The One Thing You Must Do: Get a Cohabitation Agreement

A cohabitation agreement (sometimes called a living together agreement) is a legally binding document that sets out how property, finances, and assets will be managed — both during the relationship and if it ends.

Think of it as a relationship roadmap that protects both partners and removes the guesswork from what would otherwise become very painful conversations at a very painful time.

A well-drafted cohabitation agreement typically covers:

Property ownership — who owns what percentage, and how it will be divided if you separate
Mortgage and deposit contributions — especially important if one partner contributes a larger deposit
Monthly costs and bills — how mortgage payments, utilities, and household expenses are shared
What happens if one partner wants to sell and the other doesn’t
Inheritance — what happens to each person’s share if they die
Children — arrangements for care and financial support where applicable
Savings and debts — agreements around joint accounts or individual liabilities

Without this agreement, you may have no claim to your partner’s property or savings, you may be left financially vulnerable if the relationship ends, and you may face costly legal battles over shared assets.

A cohabitation agreement provides clarity, security, and — crucially — peace of mind. And it is far cheaper and simpler to put one in place now than to try to resolve a dispute later in court.

The Second Critical Decision: Joint Tenants vs Tenants in Common

Once you have a cohabitation agreement, the next most important decision is how you register your ownership of the property with HM Land Registry. There are two options, and they work very differently.

Joint Tenancy

Under joint tenancy, you both own the whole property together — not individual defined shares. The key feature is the right of survivorship: if one partner dies, the other automatically inherits the entire property, bypassing probate entirely.

Joint tenancy is simpler and tends to suit couples who want to treat the property as entirely shared. However, it assumes a 50/50 split regardless of who paid what — so if one partner contributed a larger deposit, their extra contribution is not automatically recognised.

If the relationship breaks down, proceeds from a sale are divided equally, 50/50.

Tenancy in Common

With tenancy in common, you each own a defined, separate share of the property — and those shares can be unequal. If one partner puts in a larger deposit or has a different income, tenancy in common allows ownership to reflect those real-world contributions.

Crucially, each partner can leave their share to whoever they choose in their will. There is no automatic right of survivorship, which gives both parties more flexibility — but also means a will is essential.

For unmarried couples buying property together, many solicitors recommend tenancy in common paired with a Declaration of Trust (also called a Deed of Trust), which formally records each person’s share and what happens in various scenarios.

In short: if you’ve contributed unequal amounts, or you want your share to pass to your own children or family in the event of your death, tenancy in common is almost certainly the better structure.

Don’t Forget: Make a Will

A cohabitation agreement and the right ownership structure will protect you significantly — but there’s one more step that too many unmarried couples overlook: making a will.

If you are not married, your partner has absolutely no automatic right to inherit from you. Without a will, your estate passes according to the rules of intestacy — which prioritise blood relatives. Your partner of ten years could be left with nothing while distant relatives inherit instead.

Making a will ensures your wishes are honoured, your partner is protected, and your home doesn’t become the subject of a family dispute at the worst possible time.

What About the Proposed Law Changes?

You may have seen recent news about the government consulting on cohabitation law reform. In November 2025, the government confirmed it would launch a formal consultation on cohabitation rights in Spring 2026 — the most significant potential reform since the Law Commission first raised the issue back in 2007.

The consultation is expected to examine limited financial claims for long-term cohabiting partners, stronger protections for the financially weaker partner (often a primary caregiver), and inheritance rights for unmarried couples.

This is positive news. But here’s the reality: even if reform happens, it will take years to pass into law. And no proposed law will retroactively protect couples who didn’t take steps to protect themselves beforehand.

The law has not kept pace with how people actually live. Until it does, a cohabitation agreement remains your best and most reliable protection.

How Much Does a Cohabitation Agreement Cost?

Costs vary depending on the complexity of your situation and the solicitor you use, but a professionally drafted cohabitation agreement typically costs between £500 and £1,500. A Declaration of Trust is usually in a similar range.

Compare that to the cost of a contested property dispute — which can run into tens of thousands of pounds and years of stress — and the calculation is straightforward.

The Bottom Line for Unmarried Couples Buying Property Together

If you’re buying a home with your partner and you’re not married, here’s your checklist:

Get a cohabitation agreement — drafted by a qualified family law solicitor, covering property, finances, and what happens if you separate.
Choose the right ownership structure — tenancy in common is usually better for unmarried couples, especially where contributions are unequal.
Create a Declaration of Trust — to formally record each person’s share and protect unequal deposits.
Make a will — so your partner inherits your share of the property if you die, rather than it passing to relatives by default.
Review regularly — your agreement should be revisited every few years or whenever major life events occur, such as having children or a significant change in income.

Buying a home together is one of the most meaningful things you can do as a couple. Taking a few hours — and a few hundred pounds — to protect that investment properly is not pessimistic. It’s sensible. It’s caring. And it could save you everything.

Looking for expert guidance on buying property as an unmarried couple? Book a free initial consultation with our team today and — we’re here to help you make one of the biggest decisions of your life with complete confidence.

This article is intended for general information purposes only and does not constitute legal advice. If you are buying a property with a partner, we strongly recommend speaking with a qualified solicitor who specialises in property and family law.