In THR v WAT [2025] EWHC 1125 (Fam), His Honour Judge Hess was faced with the unenviable task of transforming a multi-million-pound Xydhias agreement into a final financial remedy order—navigating disputed terms, hidden costs, forgotten interest, and inflated child maintenance schedules. The judgment offers practitioners a rare insight into the pitfalls of rushed settlements and the court’s insistence that “a deal is a deal”—even if you think you left something out.
The Context: A Quick Settlement in a Heavyweight Case
This was a “big money” case with substantial assets on both sides. The parties had six bundles of documents and a 10-day final hearing listed, but they reached an agreement on day one—what both sides called a binding Xydhias agreement. The problem? Not everything was spelled out clearly.
Over the next few days, the drafting revealed five points of contention:
- Whether a company loan should reduce the wife's lump sum.
- Whether estimated legal fees should be adjusted post-settlement.
- Whether the lump sums should attract interest.
- Whether the wife should receive additional security.
- What level of child periodical payments (CMS top-up) the husband should pay.
Xydhias Means Finality, Not Flexibility
The husband had agreed to pay the wife £36 million, less “what she already had”—a sum which his own documents put at £2.09 million. But he later argued this was a mistake, particularly because it didn’t reflect the (supposed) value of the wife’s interest in a company called X Ltd or her reduced legal fees.
The court disagreed.
Judge Hess reminded both parties that once they reached a Xydhias agreement, the court’s role was not to re-write the deal unless there had been fraud or clear mistake. The husband, having made a firm offer based on £2.09 million, was held to it. His Honour was clear:
“There was time to raise this if it was important... a deal is a deal.”
No Interest Means... No Interest
The wife’s team attempted to insert a clause for interest on the deferred lump sums—months after the deal was struck. Judge Hess ruled this was an afterthought, not part of the agreed terms. Despite being asked to add 3.75% interest on unpaid instalments, he refused:
“If the wife’s team wanted those to be an essential part of the deal, there was plenty of time... They did not.”
Security Provisions: Reasonable, Not Total
The husband offered partial security against the lump sums, which the wife wanted increased to 100%. The judge declined, noting the husband had already paid £5 million early and was not shown to be a flight risk or unwilling to comply. The court endorsed the principle that perfect security is not always necessary where trustworthiness is evident.
Top-Up Maintenance in the HNW World
Both parties agreed the case warranted a CMS top-up order under section 8(6) of the Child Support Act 1991. But the figures were miles apart:
- Wife’s position: £50,000 per child, per annum (£150,000 total).
- Husband’s position: £20,000 per child, per annum (£60,000 total).
Judge Hess landed in the middle at £25,000 per child—totalling £75,000 per year—and made some trenchant comments about the inflated and unrealistic budget put forward by the wife. Among the claims: £120,000 on holidays, £6,000 for children’s computers, and £2,000 on Christmas gifts.
“We are dealing with children aged six, six, and three... the needs of children must be finite whatever the payer’s income.”
This aligns with the James v Seymour approach—where top-up maintenance is assessed from first principles (s.25 MCA 1973) rather than simply applying a cap or CMS formula.
Key Lessons for Practitioners
- Don’t leave “loose ends” in a Xydhias deal—spell out issues like interest, security, and assumptions about asset values at the time of agreement.
- Final means final—the court won’t revisit a deal just because one side gets buyer’s remorse.
- Avoid “aspirational” budgets—top-up child maintenance claims must be grounded in actual need, even in ultra-wealthy families.
- Security must be proportionate—perfect cover isn’t always required if the payer has a history of compliance.
Final Word
THR v WAT is a textbook example of the messiness that can follow an expensive, high-stakes settlement reached too quickly. For those dealing with big numbers and complex structures, it’s a reminder: if you want clarity, earn it at the drafting table—not by asking the court to fix what you forgot to ask for.
