A recent High Court decision concerning the Longleat estate highlights an increasingly important issue for wealthy families and their advisers; historic Trust structures do not always keep pace with modern family life. These must be kept under close review by Trust advisory specialists.
In Cator & Ors v Thynn & Anor [2026] EWHC 209 (Ch), the court was asked to approve changes to three Trusts connected to the Longleat estate after uncertainty arose over whether a child born through surrogacy fell within the class of beneficiaries.
The case is a powerful reminder that Trusts cannot simply be left untouched for decades. Regular reviews are essential to ensure structures remain aligned with a client’s wishes, family circumstances, objectives, and the modern legal landscape.
A modern family meets historic drafting: The issues
The case concerned Henry Thynn, the younger son of the 8th Marquess and Marchioness of Bath. Henry was born in the United States via a surrogacy arrangement after the Marchioness experienced serious medical complications during an earlier pregnancy.
Although Henry is the biological child of the Marquess and Marchioness, the Trust deeds (some of which dated back to before 1970) did not clearly include children born through surrogacy within the beneficiary class. That uncertainty created significant risk within a complex multi-generational Trust structure related to the whole Longleat estate. The Trustees therefore sought the court’s approval to (broadly speaking) exercise their power of advancement to allow Henry to benefit while preserving flexibility to obtain further advice, including on potential US tax implications arising from the circumstances of his birth.
The court’s approach: fairness, practicality and Trustee decision-making
The High Court approved the Trustees’ proposals, recognising that excluding Henry would be inconsistent with both fairness between siblings, the purpose of the Trusts and the family’s intentions.
Importantly, the court accepted that the Trustees had properly exercised their powers even though there was limited documentary evidence of their internal decision-making. Only one Trustee gave evidence, and there were no Trustee meeting minutes or extensive records before the court. Nevertheless, the judge held that this did not prevent approval where the substance of the evidence demonstrated that the Trustees had genuinely formed the view that the advancement was for Henry’s benefit, and for his father’s benefit also ‘both materially and morally’ on the basis it would mean he’d not need to provide for Henry out of his own resources.
The court considered the Trustees’ reasoning rational and made in good faith. A key factor was the perceived unfairness of treating Henry differently from his brother solely because he was born through surrogacy. The judge accepted that placing the children on a more equal footing provided both moral and practical benefits to the family and was a decision a reasonable body of Trustees could properly reach.
The decision reflects a broader trend in Trusts law keeping pace with modern life. Courts are increasingly prepared to support practical, Trustee-led solutions where historic drafting fails to reflect modern family structures; whether involving surrogacy, assisted reproduction, adoption or blended families.
Importantly, this is not about rewriting Trusts retrospectively. It is about ensuring long-standing structures continue to operate in the way settlors intended.
Why this matters for advisers and intermediaries
Many clients assume that once a Trust is established, it will continue to work indefinitely. In reality, Trusts can become outdated, ineffective or inconsistent with a family’s evolving circumstances. The Longleat case highlights the need for ongoing advice being crucial for Trustees, and that there are several areas of risk that advisers should be alert to:
Outdated beneficiary definitions
Terms such as “children”, “issue” and “descendants” in older Trust deeds may not adequately cater for surrogate-born, donor-conceived or adopted children, potentially leading to unintended exclusion and costly disputes.
Trustee arrangements that no longer work
Trustees appointed decades ago may no longer be suitable, available or equipped to deal with the complexities of modern Trust administration and governance. This should be kept under close review in line with Trustees’ duties and obligations.
Clear governance processes, documented reasoning
This case also demonstrates that while courts may still approve Trustee decisions where formal records are imperfect, Trustees should not rely on that outcome.
Properly maintained minutes remain best practice and can significantly reduce litigation risk.
Trusts that no longer achieve their purpose
Structures originally created for historic tax planning reasons may no longer be effective in today’s legal and tax environment and, in some cases, may create unnecessary risk. Their purpose should be kept monitored in the spirit of intention of the Trust.
Increasing cross-border complexity
International surrogacy arrangements, dual nationality and overseas tax exposure introduce issues that many older Trust structures were never designed to address.
Growing litigation risk
Ambiguity within Trust documentation remains a significant driver of contentious Trust and probate disputes, particularly in relation to high-value estates and family wealth structures. This area of law is costly and stressful for those involved.
The practical takeaway: Trusts should be reviewed regularly
The Longleat decision reinforces a simple but important point: Trusts do not update themselves.
Regular reviews of a Trust’s powers, provision, and compliance/administration and governance documentation, can help ensure that Trust structures continue to reflect a Settlor’s wishes, protect intended beneficiaries and operate effectively in light of changing family circumstances and legal developments.
Final thoughts
The Longleat case demonstrates how Trusts law is adapting to modern family life while also highlighting the risks of leaving historic structures unchecked. It also provides reassurance that courts may take a practical approach where Trustees have acted rationally and in good faith, even if historic governance records are less than perfect.
For families with trust arrangements in place or considering setting up new structures Weightmans' private wealth team can advise on ensuring documentation is appropriate and contains flexibility to adapt to evolving circumstances.
For more information, please contact our expert private wealth lawyers.
