The Unmarried Estate: Cohabitation, Intestacy and the Gaps a Will Cannot Fill

A relationship without automatic inheritance rights

Many couples in the UK now build long-term lives together without marrying or entering a civil partnership. The arrangement is ordinary, but the legal consequences can still surprise. In 2026, there is no general status of 'common-law spouse' in UK inheritance law. Length of cohabitation, shared bills, joint holidays and even shared children do not, by themselves, give a surviving partner a automatic right to inherit under the intestacy rules.

That matters most when someone dies without a valid will. The intestacy rules set out who receives the estate, and an unmarried partner is not usually among the first beneficiaries. In England and Wales, the estate generally passes to a spouse or civil partner, then to children or other blood relatives. A partner who is not married or in a civil partnership can be left outside that distribution, even after decades together.

The myth that survives the calendar

The idea of a 'common-law marriage' remains one of the most persistent misconceptions in family finance. It has no recognised legal status in England and Wales, and the same broad principle applies across the UK, although the detailed rules differ. In Scotland, a cohabitant may have a claim under the Family Law (Scotland) Act 2006, but that is a court-based route rather than an automatic entitlement. In Northern Ireland, cohabiting partners also lack the automatic intestacy rights of a spouse or civil partner.

In England and Wales, a cohabitant may be able to apply for provision from the estate under the Inheritance (Provision for Family and Dependants) Act 1975 if they lived in the same household as the deceased for at least two years immediately before death. That route can be important, but it is discretionary, fact-sensitive and potentially expensive. It is not a substitute for a will, and it does not produce the same certainty as a properly structured estate plan.

Why a will is necessary, but not always sufficient

A valid will is the starting point. It allows an unmarried partner to be named as a beneficiary and can reduce the risk of a dispute. But a will only controls assets that fall into the estate. Several important assets can pass outside it.

Property is the clearest example. If a home is held by joint tenants, the deceased's share usually passes automatically to the surviving owner by survivorship, regardless of what the will says. If the couple are tenants in common, each owns a distinct share that can be left by will. Neither structure is automatically right or wrong, but the ownership must match the couple's intentions. A deed of severance may be needed if joint tenants want their shares to pass under their wills instead.

Joint bank accounts can also pass by survivorship, and pension death benefits are usually paid at the discretion of the scheme trustees or administrators. Life insurance policies may be written in trust or paid to the estate. These arrangements sit alongside the will, and they can either support or undermine an unmarried couple's plan.

The inheritance tax dimension

Marriage and civil partnership bring valuable inheritance tax reliefs, including the spouse exemption and the ability to transfer unused nil rate bands. Unmarried partners do not generally benefit from those reliefs in the same way. A will that leaves the family home or savings to a partner may therefore create an inheritance tax liability that a married couple would not face on the same transfer.

That does not mean unmarried couples should avoid leaving assets to one another. It does mean the tax cost should be modelled before death, not discovered by the executor afterwards. In some cases, life insurance written in trust, adjustments to property ownership or a different balance between lifetime gifts and will provisions may help. The right answer depends on the size and composition of the estate, and on whether children from a previous relationship are involved.

Pensions, insurance and nominations

Pension nominations are often treated as a set-and-forget task. They deserve more attention. A nomination or expression of wish tells the scheme who the member would like to receive death benefits, but it is not always binding. Trustees may consider other dependants and the wider circumstances. For an unmarried couple, an up-to-date nomination is strong evidence of intention, but it should be reviewed after any change in circumstances.

Life insurance can be particularly useful. A policy written in trust can pay out to a named partner without waiting for probate, and the proceeds may fall outside the estate for inheritance tax purposes. That can provide immediate cash for a surviving partner who has no automatic right to the home or the bank accounts. It is not a complete solution, and premiums and policy terms vary, but it can bridge a difficult gap.

Documents that turn intention into protection

A will remains essential, but it should sit within a wider set of arrangements. A cohabitation agreement can record how a couple own property, how bills and mortgage payments are shared, and what should happen if the relationship ends or one partner dies. It can reduce uncertainty and help evidence intentions if a claim is later made.

A lasting power of attorney for finances and health and welfare is also relevant, although it is not an inheritance document. If one partner loses capacity, the other has no automatic right to manage their affairs. An LPA can provide that authority while preserving the couple's independence.

For those who choose not to marry or enter a civil partnership, the practical answer is to replicate as much certainty as the law allows. That means reviewing wills, property ownership, pension nominations, life insurance and emergency documents together, rather than treating any one of them as a complete plan.

A 2026 checklist for unmarried couples

• Make or update a valid will, and review it after any major change.
• Confirm whether the home is held as joint tenants or tenants in common, and whether that matches your intentions.
• Review pension death benefit nominations and expression of wish forms.
• Consider life insurance written in trust to provide immediate funds outside the estate.
• Record property contributions and intentions in a cohabitation agreement where appropriate.
• Take advice on inheritance tax, particularly if the estate exceeds the available nil rate bands.
• Put lasting powers of attorney in place for both partners.

Cohabitation is a legitimate and common way to build a family life. The law, however, still draws a sharp line between married and unmarried partners in several important areas. In 2026, closing that gap is less about a single document and more about aligning the will, the ownership of assets and the nominations that sit behind them.