A recent decision of the High Court of England and Wales highlights the increasing complexity faced by trustees and high-net-worth families as modern family arrangements intersect with traditional trust structures. The case demonstrates the growing need for careful drafting and proactive trust planning where assisted reproduction and surrogacy are involved.
A Modern Family Question Before the Courts
The case of Cator v Thynn (2026 EWHC 209 Ch) arose from 3 family trusts connected to the Longleat estate and centres on the family of Ceawlin Thynn. The legal issue concerned whether the Marquess’ younger son, born via a US surrogacy arrangement, could be recognised as a beneficiary under longstanding family trust structures.
Although the child is biologically related to both parents, traditional trust drafting frequently relies on terms such as “child”, “issue” or “descendant”, which historically assumes conventional birth circumstances. As reproductive technology and international surrogacy arrangements become more common, these definitions are increasingly being tested.
The Trustees’ Dilemma
In this case, the trustees were asked to consider whether to exercise powers allowing them to extend the class of beneficiaries to include the child born via surrogacy and potentially future descendants. However, doing so raised competing interests among existing beneficiaries, including siblings and more remote family members whose entitlements could be affected.
The court was not asked to decide whether the child should ultimately be included as a beneficiary. Instead, it considered whether independent legal representation should be appointed to ensure that all beneficiary interests were properly protected before any substantive decision is made. The court concluded that independent representation was appropriate, reinforcing the importance of fairness and transparency when trustees consider exercising discretionary powers.
Importantly, the court did not decide whether the child will ultimately be included as a beneficiary and that remains to be determined at a later stage.
Why This Case Matters for You
While the facts involve a prominent family, the underlying legal issues are increasingly relevant to families using modern fertility arrangements. Surrogacy arrangements—particularly those involving multiple jurisdictions—are becoming more common and can create legal and tax considerations within trust structures. This could be particularly problematic with older trust documents. As a result, trustees and settlors are facing new questions, including:
- Whether trust definitions of family members and beneficiaries remain legally robust
- How trustee discretion should be exercised where new categories of beneficiaries emerge
- The potential for disputes between different branches of a family
- The tax and regulatory implications of recognising children born through international surrogacy
- This case also serves as a reminder that trust documentation drafted even relatively recently may not adequately address modern family structures.
Practical Planning Considerations
For families, trustees and professional advisers, the case highlights several key planning priorities:
Reviewing Trust Documentation
Clear and inclusive definitions of children and descendants can reduce uncertainty and minimise future disputes. Trusts should be reviewed to ensure they reflect modern circumstances including assisted reproduction and surrogacy.
Planning for Cross-Border Arrangements
International surrogacy arrangements can introduce additional legal and tax considerations. Early advice is essential to ensure structures remain effective across jurisdictions.
Supporting Trustee Decision-Making
Trustees must balance competing beneficiary interests and ensure their decisions are properly documented and defensible. Court approval or independent representation may sometimes be advisable.
Integrating Estate and Family Planning
Surrogacy arrangements should be considered alongside wider succession planning to ensure alignment between family intentions and legal structures.
How We Can Help
As family structures continue to evolve, trust and estate planning must evolve with them. Our team regularly advises families and trustees on:
- Updating and modernising trust documentation
- Advising trustees on the exercise of discretionary powers
- Managing cross-border trust and tax issues
- Supporting families navigating surrogacy and succession planning
Looking Ahead
Although the court has not yet reached a final decision on the individual beneficiary’s status, the case signals a broader trend: traditional legal concepts of ‘family’ are being reshaped by modern reproductive technology and international family arrangements. This case illustrates the importance of reviewing existing arrangements and taking proactive legal advice to avoid uncertainty and preserve long-term family wealth structures.
If you would like to discuss how these issues may affect your own trust or succession planning, please contact a member of our team.
