Buying a house with a partner when you're not married

The one decision that matters most: how you hold the property

When two unmarried people buy together, the conveyancer will ask a question that sounds like paperwork but is actually the whole ballgame: joint tenants or tenants in common?

• Joint tenants: you own the whole property together, in equal shares, and if one of you dies the other automatically inherits their share. Simple — but it ignores unequal deposits entirely. Put in 80% of the deposit as joint tenants and you own 50%.
• Tenants in common: you each own a defined share — 50/50, 70/30, whatever you agree — and your share passes under your will, not automatically to your partner. This is usually the right choice for unequal contributions, paired with a Declaration of Trust recording the exact shares.

Many couples pick joint tenants by default because it sounds more "together." If your contributions are unequal, that default can quietly cost the bigger contributor tens of thousands of pounds.

Unequal deposits: the classic trap

The most common scenario: one partner puts in £60,000 from savings or family, the other puts in £10,000, and the mortgage is paid equally. Without a Declaration of Trust, the law's starting point for joint owners is equal shares — and proving otherwise later means a TOLATA dispute, with all the cost and stress that entails. A Declaration of Trust fixes this at purchase for a few hundred pounds: it can protect the initial deposits and then split growth equally, or set fixed percentage shares, or use a formula. Any structure is fine — what matters is that it's written down and signed before completion.

If only one name is on the mortgage

Sometimes only one partner can get the mortgage, so the property goes in their sole name — with the other partner contributing to the deposit or payments informally. This is the highest-risk setup for the unnamed partner: legally, they start with nothing, and everything depends on what they can evidence later. If you're in this position, a Declaration of Trust (yes, it works even with sole legal ownership) or at minimum a written agreement plus meticulous records of every contribution is not optional — it's the difference between having a claim and having a story.

Gifted deposits and the Bank of Mum and Dad

If a parent contributes to the deposit, everyone should be clear — in writing — whether it's a gift to one partner, a gift to both, or a loan. Mortgage lenders will usually require a signed gift letter anyway. On separation, "my parents gave us that money" and "my parents gave me that money" are very different sentences, and the paperwork from purchase decides which one is true.

Your pre-purchase checklist

1. Decide joint tenants vs tenants in common deliberately — not by default
2. If contributions are unequal, get a Declaration of Trust drafted before completion
3. Put any parental money in writing: gift or loan, to whom
4. Consider a cohabitation agreement to cover everything beyond the property itself
5. Start a contribution record from day one — deposit, fees, and every payment after