The Second Marriage and the First Family: Estate Planning for Blended Households

Blended families are now a familiar feature of British life, but the law has not become equally familiar. A will written before a second marriage, a joint tenancy that passes automatically to a surviving spouse, or an assumption that the children will be looked after can leave the first family with far less than expected. In 2026, the practical question is not whether a blended family should discuss inheritance, but how it should do so before events overtake planning.

Why remarriage changes the legal map

In England and Wales, marriage or civil partnership generally revokes an existing will unless it was made in contemplation of that marriage. This single rule catches many families unaware. A parent may have made a will years earlier, dividing assets between children from a first relationship. After a remarriage, that document may no longer do what it was intended to do.

The intestacy rules then apply. A surviving spouse or civil partner is prioritised, and children may receive a share only after the spouse’s statutory entitlement. Stepchildren do not automatically inherit from a step-parent under intestacy. In Scotland and Northern Ireland the detail differs, but the lesson is similar: silence is not a plan.

The unintended disinheritance problem

Consider a common pattern. A widow with two adult children remarries. She assumes her new husband will provide for her children, while he assumes his own children will inherit from him. If she dies first and leaves everything to him, the assets become his to use, spend or bequeath. If he later dies without making provision for her children, the first family may receive nothing.

This is often called sideways disinheritance. It does not require malice. It can arise from loyalty to a new spouse, poor advice, a failure to update documents, or simple reluctance to discuss money. The result can be a dispute between step-siblings who previously had a workable relationship.

Tools that can help

A life-interest trust is one option. The surviving spouse may have the right to occupy a property or receive income from trust assets during their lifetime, with the capital passing to chosen beneficiaries afterwards. This can give security to the survivor while preserving the intended destination of the estate. Such trusts require careful drafting and legal advice, and they are not a universal solution. Their treatment for inheritance tax, care fees and capital gains should be considered in the round.

Mirror wills are often used by couples, but they can be fragile in blended families. If each spouse leaves everything to the other and then to their respective children, the survivor remains free to change their will after the first death. A properly prepared trust, or a severance of joint tenancy so that each spouse owns a distinct share, may give more control.

Letters of wishes are not legally binding, but they can explain why a trust has been structured in a particular way. They can help trustees understand family relationships and avoid rigid assumptions. Pensions should also be reviewed. Nominations and expressions of wish do not necessarily override a scheme’s discretion, but they are part of the wider picture.

The conversation before the drafting

The most difficult work often happens before a solicitor drafts anything. Families need to discuss expectations without turning the conversation into a negotiation over every possession. Parents may wish to treat children equally, or may distinguish between needs and fairness. Stepchildren may have been part of the household for years, or may have little relationship with the deceased. A letter of wishes can record the reasoning, but it cannot replace an honest family conversation.

Timing matters. Discussions after a death are held under pressure and grief. Discussions in 2026, while everyone is well, are more likely to produce a workable outcome. Advisers can help by separating legal mechanics from emotional expectations.

A 2026 review checklist

• Confirm whether any will was made before a marriage or civil partnership, and whether it remains valid.
• List children, stepchildren and other dependants, and consider who should benefit and when.
• Check how the family home is owned: joint tenants pass automatically to the survivor, while tenants in common allow separate shares.
• Consider whether a life-interest trust or other trust structure is appropriate.
• Review pension nominations, life assurance and death-in-service benefits.
• Record the reasons for decisions in a letter of wishes where a trust is used.
• Revisit the plan after marriage, divorce, a birth, a death or a significant change in assets.

A blended family does not need a complicated plan for its own sake. It needs a clear one. The aim is to give the surviving spouse security, to treat children predictably, and to reduce the scope for arguments that no one wanted. In a modern family, that is not sentimentality. It is good administration.