Blended families - couples with children from previous relationships - now make up roughly a third of UK families with children. They also account for a disproportionate share of contested wills.
The reason isn't bad faith. It's that the default rules don't work for blended families: intestacy doesn't recognise stepchildren, and a "leave everything to my spouse" will can accidentally disinherit your own children. This article walks through the most common situations and the structures that fix them.
Why default arrangements go wrong
Take this scenario:
> Mark and Lisa are married. Mark has two children from his first marriage; Lisa has one. They each have wills leaving everything to the other "absolutely". When Mark dies, Lisa inherits everything. Years later, Lisa dies. Her will leaves everything to her child. Mark's children get nothing.
Mark didn't intend to disinherit his children. He intended to provide for Lisa first, and then for everyone's children together. But "everything to my spouse absolutely" does not protect his children - because once Lisa owns it, she can leave it to whoever she likes.
This is the blended-family classic, and it happens constantly.
The common structures that work
There are several established ways to provide for a current partner without disinheriting children from a previous relationship.
Life-interest trust ("right to occupy")
Mark's will creates a life-interest trust in his half of the family home. Lisa has the right to live in it for the rest of her life (or until she remarries, depending on the drafting). When her interest ends, the property passes to Mark's children.
Lisa is protected. The children's inheritance is preserved. Lisa can't sell the house out from under them.
Variations include:
- Right to occupy - just the home.
- Life interest - the income from a fund (e.g. interest from investments) for life, with capital preserved for the eventual beneficiaries.
- Discretionary trust - trustees decide who gets what and when, within a class of beneficiaries.
These are usually drafted by a specialist private-client solicitor. They're not appropriate for every blended family - they add complexity and ongoing administration.
Mirror wills with crossover protection
Both spouses make wills that:
- Leave personal possessions to each other.
- Leave the family home with a life-interest trust as above.
- Leave their own children a fixed share of liquid assets immediately.
- Leave the residue to the surviving spouse with a "binding trust on second death" so the eventual destination is fixed.
This is more complex than typical mirror wills but it's the most reliable structure for blended families with significant assets.
Letter of wishes for stepchildren
If you've raised stepchildren and want to provide for them, say so explicitly in the will. Don't assume "to my children" includes step-children - it usually doesn't unless defined. Either name them individually or define "my children" to include named stepchildren.
A letter of wishes alongside the will can record your reasons - useful if there's any chance of a 1975 Act claim.
What about new relationships not yet married?
Cohabiting couples in blended-family situations face two challenges layered together:
- No intestacy entitlement - if you die without a will, your partner inherits nothing automatically.
- No spouse exemption - gifts to a cohabiting partner aren't IHT-exempt.
A will is non-negotiable. See our dedicated cohabiting couples guide.
The 1975 Act risk
The Inheritance (Provision for Family and Dependants) Act 1975 lets certain people apply to court for "reasonable provision" from an estate. The relevant categories for blended families:
- Spouse or civil partner.
- Cohabitee of 2+ years.
- Child of the deceased (any age).
- Person treated as a child of the family by the deceased (this can include stepchildren).
- Anyone who was financially dependent on the deceased.
A child who is left out of a will, or given a small amount they think is unreasonable, can apply. The court considers the deceased's reasons (a letter of wishes helps here), the child's circumstances, the size of the estate, and other claims.
You can't completely "1975-Act-proof" a will, but you can:
- Be clear about your reasons.
- Give some provision rather than nothing where possible.
- Use trusts and letters of wishes to record intent.
- Discuss with the affected person while alive (this is uncomfortable but it's the most effective preventive step).
Common blended-family will mistakes
- "Everything to my spouse" with no protective trust. Reliable when you have only joint children. Risky when there are children from previous relationships.
- Verbal promises. "Tell the children I'll always do right by them." Verbal promises are unenforceable.
- Inconsistent definitions. "I leave my house to my children" - which children? All of them? Only the biological ones?
- Out-of-date wills. A will written before the new relationship leaves everything to the previous family. Marriage revokes a will, but cohabitation doesn't.
- Joint tenancy on the family home. Joint tenancy passes the entire property to the survivor by survivorship - regardless of what the will says. If you want to preserve a share for children, change to tenancy in common.
Family conversations
The most effective tool for blended families is honest conversation in advance. Children grown up with a step-parent will often accept any reasonable arrangement if it's explained while everyone is alive. The same arrangement coming as a surprise after death produces conflict.
A typical conversation covers:
- Who is the surviving spouse going to live with / where?
- Who gets specific personal items of sentimental value?
- Are there any debts or obligations the children should know about?
- Have all wills been updated and aligned?
For complex estates, we recommend you seek assistance from a Trusted Hands Advisor or your own legal advice.
> Ready to start your will? Trusted Hands turns these decisions into a 15-30 minute guided builder. Start free → — only pay when you download.
Frequently asked questions
Can I leave everything to my new spouse and trust them to look after my children?
Legally, yes. Practically, this is the structure that fails most often. The new spouse is entirely free to write their own will leaving everything to their own children. A life-interest trust gives the spouse the practical benefit (a place to live, income) without giving them the right to redirect the inheritance.
Are stepchildren classed as children for inheritance purposes?
Not under intestacy rules - only biological and legally adopted children. If you want a stepchild to inherit, name them in the will.
Can my ex-spouse claim from my estate?
Generally not unless there's an outstanding maintenance order, or unless they fall into another 1975 Act category. A clean financial order from the divorce is the best protection.
What if I want to leave nothing to a child I'm estranged from?
You can - but they may apply under the 1975 Act for reasonable provision. Record your reasons in writing in a letter of wishes, give a small token gift if you can stomach it (which makes a 1975 Act claim much harder), and review the will every few years.
Do mirror wills work for blended families?
Standard mirror wills (everything to the survivor, then to all children equally) often don't work because the survivor can change their will after the first death. Blended-family mirror wills with binding crossover protection are different and much more reliable.
A clear will is the most reliable protection. Start yours online - the Trusted Hands complexity engine flags blended-family situations and prompts you toward the right structure.
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