Can A One-Year Marriage Lead To A Multi-Million-Pound Estate Claim? Lessons From Thirsk V Thirsk

A recent High Court decision has provided useful guidance on how the courts balance inherited wealth, long-term relationships and the financial needs of a surviving spouse in the case of Thirsk v Thirsk & Ors [2026].

What happened?

The claimant, Mrs Thirsk, brought a claim against the estate of her late husband, Mr Thirsk, following his death in 2022. Although the couple had only been legally married for around a year at the date of Mr Thirsk’s passing, they had cohabited for approximately 19 years prior to their marriage.

Mr Thirsk’s estate was valued at over £26 million and consisted largely of agricultural land, a farming business and various commercial properties. Mr and Mrs Thirsk were thought to have shared a lavish lifestyle, with their living expenses amounting to over £700,000 per annum.

Mr Thirsk intended to provide for his surviving spouse as set out in his Will with a £5 million tax-free legacy, the right to occupy the former family home for the remainder of her lifetime (subject to restrictions), and a number of valuable personal possessions, including luxurious cars.

The Will then sets out that the remainder of Mr Thirsk’s estate is to be inherited by his son from a previous relationship.

Mrs Thirsk argued that the provision made for her in the Will was insufficient and sought substantially greater financial provision by making a claim against the estate under the Inheritance (Provision for Family and Dependants) Act 1975. The 1975 Act allows for certain individuals to make a claim against an estate if they do not believe that they have received reasonable financial provision from the deceased.

The Court’s approach

The Court considered the factors set out in the 1975 Act, including:

• Mrs Thirsk’s financial needs and resources;
• The size and nature of the estate;
• The length of the relationship, particularly prior to their legal marriage;
• Mr Thirsk’s obligations and responsibilities; and
• What Mrs Thirsk might reasonably have received had the marriage ended in divorce rather than death.

A significant issue which was considered by the Court was whether the wealth generated from land inherited by Mr Thirsk before the relationship should be treated as matrimonial property capable of being shared. The Court examined recent Supreme Court guidance on "matrimonialisation" and the distinction between matrimonial and non-matrimonial assets.

The judge concluded that a substantial proportion of the assets remained non-matrimonial because they originated from Mr Thirsk’s inherited wealth and there was limited evidence that he intended to share those assets with his wife during the relationship. However, some assets acquired during the relationship were considered matrimonial and therefore capable of being shared.

The outcome

The Court found that the provisions contained in the Will did not amount to reasonable financial provision because under the Will, Mrs Thirsk’s right to remain in the family home was restricted and could be lost if she entered a new cohabiting relationship.

The judge ultimately ordered provision broadly in line with an offer made by the deceased's son. This included an outright transfer of Mrs Thirsk’s home; a £5 million lump sum; interest on unpaid legacy sums; and retention of certain personal assets already received under the Will. The Court concluded that this package provided reasonable financial provision for Mrs Thirsk [AK1] in all the circumstances of the case.

Another point to note is that although Mrs Thirsk argued for lifelong maintenance support, given the length of the relationship, Mrs Thirsk’s age and the significant age difference between her and Mr Thirsk, the Court instead capitalised her maintenance claim over a limited period, finding that reasonable financial provision did not require indefinite support and that she should ultimately be expected to achieve financial independence.

Why is this relevant to family law clients?

Although this was an inheritance dispute rather than a divorce case, the judgement is of particular interest to family law matters because it demonstrates the close relationship between inheritance claims and financial remedy principles.

The Court carried out what is often referred to as the "divorce cross-check", considering what Mrs Thirsk might have received had the marriage ended through divorce rather than death. This required detailed analysis of matrimonial versus non-matrimonial assets, the sharing principle, housing and income needs, cohabitation prior to marriage, and the parties' standard of living during the relationship. These are issues regularly encountered in family law cases.

The decision highlights a number of important points for our clients:

• Long periods of cohabitation may carry significant weight when the Court considers financial provision, even where the marriage itself was relatively short.
• Assets inherited or acquired before a relationship may not automatically be shared, particularly where there is evidence that they were kept separate.
• Lifelong maintenance cannot be assumed, even in cases involving significant wealth. There is a growing emphasis in both the Family and Civil Courts on achieving financial independence where possible rather than creating indefinite financial dependency.
• Careful estate planning, pre-nuptial agreements and post-nuptial agreements can play an important role in managing expectations and reducing disputes.

At JCP Solicitors, our Family Law team regularly advises clients on financial settlements following relationship breakdown, including cases involving inherited wealth, farming businesses, family  enterprises and non-matrimonial assets. Whether navigating a relationship breakdown, seeking to protect assets before marriage, or concerned about the financial implications of inheritance, obtaining specialist advice at an early stage is essential.

We also work closely with colleagues in our Lifetime Planning team and our Inheritance and Trust Disputes team, enabling us to provide joined up advice where family law and inheritance issues intersect. If you would like advice tailored to your circumstances, our experienced team would be happy to help.

Why is this relevant to Lifetime Planning clients?

The case demonstrates that even where an individual has clear intentions as to who should benefit from their estate, those wishes can be challenged if their estate planning does not adequately account for the needs and rights of a surviving spouse.

Although the deceased had made a Will, unresolved discussions about post-nuptial arrangements and a lack of more comprehensive planning created uncertainty, ultimately resulting in lengthy and costly litigation.

At JCP Solicitors, our Lifetime Planning team can help individuals to put the important arrangements in place by creating an accurate Will with supporting Statements and/or Letters of Wishes where practical. We also always advise to regularly review your Will to ensure that it remains relevant to your current circumstances and wishes. The team are also professionally qualified to advise on any further protections which may be suited to your unique circumstances; such as trusts set up during lifetime or under your Will.

Ultimately, this case serves as a valuable reminder that estate planning should not be viewed as a one-off task. Major life events such as cohabitation, marriage, inheritance, business growth and changes in family circumstances should prompt a review of existing arrangements. Obtaining advice from a professionally qualified lawyer at the right time can help ensure that wishes are clearly documented and are more likely to be upheld if they are ever subject to judgement by the court. Careful planning can reduce the risk of future disputes, provide greater certainty for loved ones, and help preserve family wealth for future generations.

This case is a reminder that divorce, cohabitation, succession planning and inheritance claims are often closely connected. Seeking specialist advice at an early stage can help individuals protect assets, plan for the future and reduce the risk of costly litigation for loved ones.

For more information or guidance, please contact our team at hello@jcpsolicitors.co.uk or call 03333 208644.