This article examines how recent High Court proceedings involving the Marquis of Bath’s family trusts expose the legal complexities surrogacy creates for inheritance, trusts and succession.

The news that High Court proceedings have been brought by the trustees of the Marquis of Bath’s family trusts sheds a vivid light on a thorny issue facing surrogacy and inheritance law, especially for families where succession to wealth – and titles – are strictly prescribed. The court was asked to recognise that Lord and Lady Bath’s younger son Henry — born via a Californian surrogate in 2016 — should be treated as falling within the class of beneficiaries under three trusts structured according to pre‑1970 common‑law definitions of ‘child’, which would typically not include a child born via surrogacy.

The claim was heard by the highly respected and learned judge His Honour Judge Paul Matthews (sitting as a judge of the High Court) in Bristol on 6 February. While HHJ Matthews was willing to approve the Thynn family the power to add Henry as a beneficiary of the trusts, he stressed that affirming his rights now might well prejudice the rights of Henry’s older brother or other future siblings (and indeed future generations of the family).

This issue is not just about one prominent family. More families will increasingly find themselves navigating the same legal shoals. The admirable unity over the wish to treat Henry equally with his siblings shown by the Thynn family and its trustees will not be true of every family in the same position, and other cases (which are already arising in England and elsewhere, though not publicly reported) may well lead to a different result. The difficulty in precedent-based legal system such as that in England and Wales is how to do justice in every case, when different families might have starkly contrasting objectives.

These considerations have the potential to put trustees of family trusts in a very difficult position – especially where not all the beneficiaries are united. It is not hard to predict great disharmony and protracted legal battles where one branch of a family wishes a child to be included within the class of trust beneficiaries and other branches are resolutely opposed.

Fundamentally, the difficulty is that children born through surrogacy straddle multiple legislative regimes — from the Family Law Reform Acts to the Human Fertilisation and Embryology Acts and the Surrogacy Arrangements Act — creating a complex and often inconsistent legal environment. The Family Law Reform Acts, while widening definitions around legitimacy, were never designed to address surrogacy’s modern complexities. As a result, what fits neatly for one family may fit poorly — or not at all — for another.

Another issue illustrated by surrogacy arrangements giving rise to Henry Thynne’s birth is that because he was born in America to an American mother, he automatically became a US person at birth. So the trusts cannot be reorganised to accommodate him as a beneficiary without potentially triggering significant international tax issues. Assuming Henry wishes, it should be possible to take steps to avoid those in the future. But given the typically international nature of surrogacy arrangements, the case is a useful reminder of the tax issues that can arise, the Thynn family are also fortunate that the change contemplated to bring Henry within the class of trust beneficiaries can be achieved in this case without significant UK tax hurdles to overcome. Again, that will not always be the case.

Lastly, while the High Court was able to deal with Henry’s position in relation to the family trusts, it does not have jurisdiction to alter the succession to the Thynn family’s titles. Since the Royal Warrant of 1 April 2011, children of peers conceived through assisted reproductive methods (including IVF and surrogacy, for example) are entitled to use courtesy titles as the (younger) children of a peer, mirroring the position for adopted children, which has been in place since 2004, they are not included within the line of succession to the substantive peerage(s).

This case illustrates that in cutting‑edge family law, a one‑size‑fits‑all approach is impossible; the law must adapt to accommodate each family’s unique circumstances.