Marcus v Marcus: judgment gives non-biological child entitlement to Trust

On 24^th June 2025, the High Court dismissed an appeal from Jonathan Marcus, who argued that his half-brother should not be entitled to any of his late father’s trust assets as he was not biologically related.

Marcus v Marcus: what happened?

Stuart Marcus was a successful businessman in the children’s toy industry. He and his wife, Patricia, had two children, Edward and Jonathan, who were raised as brothers. The couple created Settlement Trusts for their sons to delay payments of Capital Gains Tax.

In 2020, Stuart passed away, leaving assets worth around £14.5m to “the children and remoter issue of the Settlor” (the Trust beneficiaries, being Edward and Jonathan).

Unbeknownst to Stuart, in 2010, Patricia told Edward that Stuart was not his biological father because of an affair she had had. Jonathan discovered this in 2023 and brought a High Court inheritance dispute claim, stating that Edward should not be entitled to any of the Trust assets as a discretionary beneficiary on the basis that he was not Stuart’s biological child.

What is a Settlement Trust?

A Settlement Trust is an arrangement whereby a ‘settlor’ (in this case, Stuart) transfers assets (for example, money, property, or investments) into a Trust, which is managed by Trustees for the benefit of other people (beneficiaries).

This type of Trust is designed to manage and protect assets, often to ensure they are used responsibly.

The High Court’s ruling

At the ruling, a large focus was on the construction of the words “children and remoter issue” and whether Edward could be included in these terms.

DNA testing was carried out to determine paternity. Although there were some issues with the DNA report, which was heavily caveated, the Judge ruled that the DNA results supported that Jonathan and Edward were half-siblings. After this was established, the Court had to determine whether Edward was a child of Stuart’s for the purpose of the Trust.

Stuart’s Trust did not refer to Edward or Jonathan by their name, but as “children”. The court then had to ‘ascertain the objective meaning of the language’, analysing the law, authorities, and expert opinions to understand the Trust in the context of this scenario.

Master Marsh delivered the judgment, stating:

“I consider that the surrounding circumstances point overwhelmingly in favour of a wider meaning than a biological child being adopted. A reasonable person in knowledge of the relevant facts would readily conclude that when using ‘children’, Stuart intended this word to be understood as meaning Edward and Jonathan, and not ‘Edward and Jonathan provided they are in fact my biological sons.’ Crucially, there was no reason to consider that Stuart might have intended to treat Edward and Jonathan unequally. The inequality that would arise between the two settlements by applying the natural meaning of children is stark.”

Essentially, when Stuart used the word “children”, it is likely that he did not just mean biological children, and the nature of his relationship with Edward and Jonathan suggests that he intended for both to be included.

Read the full Marcus v Marcus ruling here.

What we can learn from the Marcus v Marcus case

Trusts can be a complex area of law to deal with. Even in the case of Marcus v Marcus, where Stuart had legally set out his wishes in a Trust, unexpected things can crop up, leading to family disputes. Although there is no way of anticipating all potential issues that could arise further down the line, there are things to consider:

Unqualified terms can lead to disputes: be explicit

Trust documents can contain complicated language for the Trustee(s) and beneficiaries to understand. This can cause a dispute when interpreting what is really meant; for example, in the case of Marcus v Marcus, Stuart referred to Edward and Jonathan as “children” and not specifically by their names, without defining who he was referring to. This type of dispute can be avoided by using names and/or explicit terms in the Trust.

How to avoid a Trust dispute

Views on how a Trust should be administered can be interpreted differently for each Trustee. This is why it’s so important to have clear documentation and to choose Trustees that are trustworthy (as the term implies!).

Trust disputes can also be avoided by reviewing the Trust and its terms when any new major changes/circumstances occur, such as getting married, remarrying or having children. You should also keep your Trustees and beneficiaries up to date with trust matters.

Create a letter of wishes

A letter of wishes is an informal document that goes alongside your Will to provide guidance to executors and Trustees on how to distribute assets and manage affairs after you pass away. Whilst the document can offer useful guidance, it is not legally binding and should not be used in place of a Will.

Contact our inheritance disputes solicitors

If a loved one’s Trust is causing a dispute in your family, our estate dispute lawyers might be able to help. Call our specialist team today on 0117 325 2929 or fill out our online enquiry form.