Second Marriages and Wills: Protecting Children From a Previous Relationship

Second marriages and blended families create genuine estate planning challenges that a simple, straightforward will often doesn’t address well - and getting it wrong can mean children from a first marriage inadvertently receive nothing.

Why a simple ‘mirror will’ often doesn’t work for blended families

Many couples use ‘mirror wills’ - each leaving everything to the surviving spouse, then to their children when the survivor later dies. In a second marriage with children from a previous relationship, this structure carries a real risk: once the first spouse dies and everything passes to the survivor, the survivor can change their own will at any time - potentially leaving everything to their own children (or a new partner, if they remarry again), cutting out the first spouse’s children entirely, even if that was never the original intention.

Why intestacy makes this worse, not better

If a second marriage occurs without new wills being made, dying without a will (see our dedicated intestacy article) applies the same fixed formula regardless of previous relationships - step-children have no automatic right to inherit under intestacy rules unless legally adopted. If a parent in a second marriage dies intestate, their spouse takes the personal possessions, the first £322,000 and half of anything above that, so children from a first marriage may receive little or nothing - and whatever passes to the step-parent can later go to the step-parent’s own family instead.

A common solution: life interest trusts

A frequently used structure lets the surviving spouse have the right to live in the family home and/or receive income from investments for their lifetime, while the underlying capital is preserved and ultimately passes to the first spouse’s children when the survivor later dies - balancing genuine provision for the second spouse during their lifetime with protecting the inheritance intended for children from the first marriage (see our dedicated trusts article for how this type of arrangement works more generally).

Being explicit about what each spouse brought into the marriage

Couples in second marriages sometimes have very different levels of pre-existing assets, property, or children to provide for - being explicit in the will (and ideally in conversation with all parties beforehand) about what’s intended for whom reduces the risk of disputes or perceived unfairness after death, which is a common source of family conflict specifically in blended family estates.

Considering a prenuptial or postnuptial agreement alongside estate planning

While not strictly a will or estate planning tool, a prenuptial agreement (before marriage) or postnuptial agreement (after marriage) can clarify intentions about existing assets brought into a second marriage, which can complement and inform how wills and trusts are subsequently structured - particularly relevant if there’s a significant disparity in assets between spouses.

The Inheritance (Provision for Family and Dependants) Act 1975

Even with a carefully drafted will, certain people - including a spouse, former spouse who hasn’t remarried, children, step-children treated as a child of the family, and some other dependants - can potentially make a claim against an estate if they feel they haven’t received ‘reasonable financial provision’ (see our dedicated article on contesting a will). This is a relevant consideration in blended family planning, since a will that appears to unfairly exclude a spouse or child (even from a previous relationship) may be vulnerable to this kind of claim.

Practical steps for second marriages

• Review or write new wills specifically after a second marriage - a will is automatically revoked by marriage in England and Wales unless it was made in specific contemplation of that marriage, so an old will from before a second marriage may not even be valid. (The Law Commission has recommended abolishing this rule, but as of October 2026 it has not been changed, so it still applies.)
• Consider a life interest trust structure if you want to provide for a second spouse while ultimately preserving assets for children from a first marriage.
• Discuss intentions openly with all adult children involved, where possible, to reduce the risk of disputes or surprises after death.
• Get specialist advice, since blended family estate planning genuinely benefits from a solicitor experienced in this specific area, rather than a generic will template.

The bottom line

Second marriages create genuine estate planning complexity that simple mirror wills often don’t address adequately - a life interest trust structure, specifically drafted with input from a specialist solicitor, is frequently the right tool for balancing provision for a second spouse against preserving an inheritance for children from a first marriage.