In England and Wales, unmarried partners have no automatic legal right to each other's property, regardless of how long they have lived together. There is no such thing as a common-law spouse in English property law. If you buy together without a deed of trust, you risk losing money you cannot afford to lose.\n\nWhy You Need a Deed of Trust — When two people buy a property together, they are registered at the Land Registry as either joint tenants (owning equal shares with automatic right of survivorship) or tenants in common (owning defined shares, potentially unequal, with each share passing according to their will). The Land Registry records the ownership structure but not the financial details — it does not record who paid the deposit, who pays more toward the mortgage, or what happens to the money if you sell.\n\nA deed of trust fills this gap. It is a legally binding document that records each person's financial contribution and ownership share, what happens to the deposit money if the property is sold, how to divide the equity if you separate, who pays the mortgage and other costs, and what happens if one person wants to sell and the other does not.\n\nUnequal Contributions — The most common scenario. One person puts in 50,000 deposit and the other puts in 10,000. Without a deed of trust, if they are joint tenants, the property is divided 50-50, and the person who contributed more loses 20,000 of their original deposit. A deed of trust records the unequal contributions and protects the larger contributor.\n\nHow It Works — A deed of trust can be structured several ways. Fixed shares: each person owns a defined percentage, for example 60-40 reflecting deposit contributions. Floating shares: shares adjust over time based on mortgage contributions and improvements. First-charge model: one person's larger deposit is repaid first from sale proceeds, with remaining equity split equally.\n\nCohabitation Agreements — Broader than a deed of trust, a cohabitation agreement covers the property plus other financial arrangements: who pays which bills, what happens to joint savings, how shared debts are handled, and arrangements for any children. While not always legally binding in the way a marriage settlement is, courts give them significant weight.\n\nCost — A straightforward deed of trust costs 200 to 500 through a solicitor. A comprehensive cohabitation agreement costs 500 to 1,500. Given that the alternative is potentially losing tens of thousands in a dispute, this is some of the best value legal spending you can do.\n\nWhen to Arrange It — Ideally before or at the point of purchase. Your conveyancing solicitor can draft it as part of the buying process. If you already own a property together without one, it is not too late. A solicitor can draft a deed of trust at any time, though both parties must agree to the terms. If you cannot agree, that itself is a warning sign.