Increasing numbers of UK couples buy property together without being married or in a civil partnership — but unmarried couples don't automatically get the same legal protections married couples do, which makes a few extra conversations genuinely important before signing anything.

How a joint mortgage works regardless of marital status

From a lender's perspective, a joint mortgage application works the same way whether or not you're married: both incomes are typically assessed together, and both applicants are usually "jointly and severally liable" — meaning each of you is individually responsible for the full mortgage debt, not just an agreed share, if the other can't pay.

Why ownership structure matters more for unmarried couples

Married couples have some default legal protections around property division if they separate; unmarried couples generally do not, which means how you legally hold the property together has real, practical consequences if the relationship ends.

Joint tenants vs tenants in common

  • Joint tenants: You own the whole property together equally, with no individually defined shares. If one owner dies, their share automatically passes to the other, regardless of what a will says.
  • Tenants in common: You each own a defined, specific share of the property — which can be unequal, reflecting different deposit contributions, for example. Your share can be left to someone else in your will, and doesn't automatically pass to your co-owner.
Unmarried couples contributing unequal amounts to a deposit or mortgage often benefit from tenants in common, with a Declaration of Trust setting out exactly what share each person owns — protecting the person who put in more if the relationship later ends.

What a Declaration of Trust covers

A Declaration of Trust is a legal document, drawn up by a solicitor, that records each person's financial contribution and agreed share of the property, and can also cover what happens if one person wants to sell, or how ongoing costs are split. It's not legally required, but for unmarried couples it's one of the most valuable, low-cost pieces of protection available.

What happens if you separate?

Without marriage, there's no automatic entitlement to a share of the property based on the relationship alone — ownership generally follows what's legally documented (the title deeds and any Declaration of Trust), not what feels fair based on the relationship. This is precisely why documenting contributions properly at the outset matters so much more for unmarried couples.

Practical steps before applying together

  1. Discuss and agree how the deposit and ongoing mortgage payments will be split
  2. Decide between joint tenants and tenants in common based on your contributions and wishes
  3. Consider a Declaration of Trust, particularly if contributions are unequal
  4. Review or update your wills, since property ownership can interact with inheritance in ways that differ from married couples
  5. Consider what would happen to the mortgage and property if you separated, before you're in that situation

For related reading, see our guides on Guarantor and Joint Mortgages: A Practical Guide and How Much Deposit Do You Need for a UK Mortgage?.

To run your own numbers, try our Mortgage Affordability Calculator.

The bottom line

Buying with an unmarried partner is financially and practically very similar to buying as a married couple from a lender's point of view, but the legal protections around what happens afterward are meaningfully different. A short conversation with a solicitor about ownership structure and a Declaration of Trust, before you complete, is one of the most valuable steps unmarried co-buyers can take.

This article is for general information only and does not constitute financial, legal or tax advice. Rates, thresholds and eligibility criteria change over time — always check current terms with the lender or an FCA-regulated adviser before making a decision. See our full terms and disclaimer.