A second marriage rewrites the estate twice: once when the wedding cancels the old will, and again when the new one leaves everything to the new spouse. The children of the first marriage then inherit only what the survivor chooses. English law has a settled answer, the life interest trust, and it protects both sides without costing the spouse exemption. This page is that answer, and the claims that follow when it is not used.
The problem
GOV.UK lists, among the cases where you should get advice on a will, several family members who may claim, such as a second spouse or children from another marriage (GOV.UK, Making a will: write your will, checked 1 November 2026). Two rules make it a problem rather than a preference.
The first is that marriage revokes an earlier will (Wills Act 1837, section 18, checked 1 November 2026), so the will that provided for the children died at the wedding. The second is that an outright gift to the spouse is theirs absolutely: they can spend it, leave it to their own children, or remarry and lose their will in turn. Our dying without a will page covers what happens if no new will is made.
The life interest trust
GOV.UK describes the mechanism under its trusts guidance. An interest in possession trust is one where the trustees must pass all the income to the beneficiary as it arises. Its example is shares whose income goes to your wife for life, with the shares passing to your children when she dies (GOV.UK, Trusts and taxes: types of trust, checked 1 November 2026).
Applied to the family home, the spouse has the right to live there for life and the children own it afterwards. GOV.UK’s Inheritance Tax guidance describes exactly that: a person given a right to live in the family home following the death of their spouse, with the home held in trust for the lifetime of the beneficiary (GOV.UK, Trusts and Inheritance Tax, checked 1 November 2026). The survivor cannot sell it out from under the children or will it away; the children cannot put the survivor out.
The tax, which is not worse
An immediate post-death interest is HMRC’s name for a life interest created by a will. Its manual says such an interest is treated as forming part of the beneficiary’s estate for Inheritance Tax (HMRC Inheritance Tax Manual, IHTM16061, checked 1 November 2026). Treated as the spouse’s, it takes the spouse exemption on the first death.
The home allowance survives too. GOV.UK says that where the home is held in trust for the lifetime of the surviving spouse, the estate is eligible for the additional threshold when the beneficiary dies as long as their direct descendants then inherit the home, and contrasts a discretionary trust, which loses it (GOV.UK, Trusts and Inheritance Tax, checked 1 November 2026). HMRC’s manual gives a related case: a deceased leaves £500,000 to his spouse on life interest trusts and the residue, including the house, directly to his children, and the house counts as closely inherited on the first death (HMRC Inheritance Tax Manual, IHTM46033, checked 1 November 2026). Our Inheritance Tax hub covers the thresholds.
Mirror wills and mutual wills
Couples ask for mirror wills, two wills in matching terms, each leaving everything to the other and then to the children. They protect nothing after the first death: the survivor’s will is theirs to change, and a remarriage cancels it anyway.
Mutual wills are different: the couple agree that neither will change theirs after the first death, and the courts enforce that agreement against the survivor’s estate.
Neither term appears on GOV.UK, and this is general legal information rather than a sourced rule. Mutual wills are made rarely and with advice, because they bind a survivor who may live thirty years. The life interest trust achieves the protection without the bind, which is why solicitors reach for it first.
The claim a partner or child can bring
Where the will provides for nobody but the spouse, or for nobody at all, the Inheritance Act lets the court intervene. It lists who may apply for reasonable financial provision, and the list reaches well beyond the spouse (Inheritance (Provision for Family and Dependants) Act 1975, section 1, checked 1 November 2026).
On it are the spouse or civil partner, a former spouse who has not remarried, a child, a person treated by the deceased as a child of the family, a person being maintained by the deceased, and a person who lived in the same household for the whole of the two years before the death as if married. The Act says the application may not be made, without the court’s permission, after six months from the date representation is first taken out (section 4, checked 1 November 2026). A stepchild raised in the house, an unmarried partner of decades and a disabled adult child are all on the list, and our seeing and contesting a will page covers the mechanics. A will that provides for each of them is the reason no claim is brought.
Capacity where dementia is present
A will made by someone whose memory is failing is the will most often challenged, and a diagnosis is not a bar. GOV.UK’s test is that the person is of sound mind (GOV.UK, Making a will: make sure your will is legal, checked 1 November 2026), and the code of practice below explains how that is judged.
The Mental Capacity Act’s code of practice says capacity to make a will is one of the tests set by the courts, which the Act’s own definition sits alongside but does not replace (Mental Capacity Act code of practice, chapter 4, checked 1 November 2026).
The code says the starting assumption must be that the person has capacity, and that an assessment should be carried out when capacity is in doubt. A diagnosis of dementia is not a bar; a doctor’s capacity assessment on the file, and a solicitor who saw the person alone, give the executors evidence they would not otherwise have. GOV.UK gives no step-by-step for that, and the solicitor is the person who arranges it. Our LPA hub covers the document for managing money while the person is alive, which is the more urgent one once capacity is slipping.
Unmarried partners
A partner who is not married or in a civil partnership is invisible to the intestacy rules and to the spouse exemption alike. GOV.UK says a partner who was not married or in a civil partnership has no automatic right to inherit (GOV.UK, Intestacy, checked 1 November 2026), and cannot apply to be the administrator (GOV.UK, Applying for probate: if there is not a will, checked 1 November 2026).
The Inheritance Tax hub covers the 40% that GOV.UK says applies to whatever a will leaves them above the threshold (GOV.UK, How Inheritance Tax works: thresholds, rules and allowances: Overview, checked 1 November 2026).
The will is the whole of their protection, and a life interest in the home for the partner with the capital to the children works for an unmarried couple as it does for a married one, without the exemption. Marrying changes the tax; a will changes who inherits at all.
What a solicitor is for
GOV.UK says to get advice where a will is not straightforward and puts a second spouse or children from another marriage on its list (GOV.UK, Making a will: write your will, checked 1 November 2026). A life interest trust is a document a solicitor drafts, not a form.
The Competition and Markets Authority’s concerns about unregulated will-writers, low headline fees that rise and terms that appoint the firm as executor for a fee, bear most on exactly these wills (GOV.UK, CMA investigates will-writing and other legal services, checked 1 November 2026).
A life interest trust needs trustees, a power to move house, and words that survive a remarriage, and our will terms page explains the vocabulary the draft will use. The wills hub covers what makes the document valid once it is written.