How do you plan an estate with children from more than one relationship?
Simple mirror wills work where both partners have the same children and fail where they do not. Everything passes to the survivor, who is then free to change their will, remarry, or spend it — and the children of the first to die can end up with nothing, without anyone having intended it.
- The failure: the survivor inherits absolutely and can change their will afterwards.
- Remarriage: revokes an existing will in England and Wales unless it was made in contemplation of it.
- The usual answer: a life interest trust giving the survivor income and use, with capital to named children.
- The residence band: still available where the home passes in the end to direct descendants.
01 Why mirror wills fail here
A mirror will leaves everything to the survivor and then to the children on the second death. Where the children are the same, that works. Where each partner has children from a previous relationship, the outcome rests entirely on the survivor keeping the promise after the first death — and nothing binds them to it.
The survivor can make a new will at any time. They can also spend the money, give it away, or be influenced by a new relationship. None of that is bad faith; it is what absolute ownership means.
Mutual wills, which purport to be binding, exist and are difficult to establish and frequently litigated. They are not a reliable solution to this problem.
Shows: what each set of children receives if the survivor's will leaves everything to their own children. Ignores: Inheritance Tax, the survivor's own assets, and any life interest arrangement.
On the defaults above, the worked example shows £0. Your children receive £0 and theirs receive £350,000 each — the outcome mirror wills permit if the survivor changes theirs.
Source: Wills, probate and inheritance
02 Remarriage revokes a will
In England and Wales, marriage revokes an existing will unless it was expressly made in contemplation of that marriage. A survivor who remarries without making a new will therefore dies intestate, and the intestacy rules give a substantial share to the new spouse.
That is the mechanism by which children of a first relationship are most often disinherited, and it happens without anybody deciding to disinherit them. It is a rule, not a choice.
Anyone in a blended family who remarries should make a new will immediately, and anyone planning to should make one in contemplation of the marriage beforehand.
Source: Make a will
03 What a life interest trust does
A life interest trust — sometimes called an immediate post-death interest — gives the survivor the right to income from the assets and to live in the property for their lifetime, with the capital passing to named beneficiaries afterwards. The survivor is provided for and cannot redirect the capital.
It is created by the will rather than during life, so it avoids the entry charge that applies to a lifetime discretionary trust, and it can preserve the residence nil-rate band where the property passes in the end to direct descendants.
It needs trustees who will actually act, and it creates a relationship between the survivor and the children of the first to die that has to work in practice. Naming a professional trustee alongside a family one is common for exactly that reason.
Source: Passing on a home
Mirror wills in a blended family are a promise, not a plan. The survivor owns everything absolutely and can change their will the following week — and even if they never would, marriage revokes a will in England and Wales, so a remarriage without a new will sends a large share to the new spouse under the intestacy rules. Nobody decided that; a rule did. If you have children from a previous relationship, a life interest trust in the will is the standard answer: the survivor gets the income and the home for life, and the capital goes where you intended.
FAQ
Are mirror wills enough for a blended family?
No. The survivor inherits absolutely and can make a new will at any time, spend the money or remarry. Mirror wills express an intention without binding anyone to it.
Does remarriage really cancel a will?
In England and Wales, yes, unless the will was expressly made in contemplation of that marriage. A survivor who remarries and does not make a new will dies intestate, and the intestacy rules give a substantial share to the new spouse.
What is a life interest trust?
A trust created by the will giving the survivor income from the assets and the right to occupy the property for life, with the capital passing afterwards to named beneficiaries. It provides for the survivor without letting them redirect the capital.
Sources
Regulator references
- Wills, probate and inheritance · GOV.UK · 2025The intestacy rules that apply when no valid will exists.Last verified: 2026-09-07
- Make a will · GOV.UK · 2025The formal requirements a will has to meet to be valid.Last verified: 2026-09-07
- Passing on a home · GOV.UK · 2025The residence nil-rate band and the taper that removes it on large estates.Last verified: 2026-09-07
Calculator unit tests · the assertions this page's worked example is checked against, and their last result
Changelog
- 2026-09-07 — initial publish (new format)
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Jordan Reeves
Founder of Talk Through Wealth. A software engineer for over a decade before turning to retirement planning, Jordan built the projection engine after watching family members get fragmented, country-by-country advice that never reconciled. He writes about retirement the way the engine computes it: month-by-month, lifetime-long, and skeptical of any rule of thumb that hasn't been run through the math.