De La Sala & Anor v De La Sala & Ors [2026] EWCA 282

Moylan, Andrews, and Nugee LJJ. The Court of Appeal dismissed two appeals from a set-aside order made by HHJ Hess sitting as a deputy High Court judge. The court considered issues of material non-disclosure by the husband, and whether gifts made by the wife’s mother were conditional.

Judgment date: 17 March 2026

https://caselaw.nationalarchives.gov.uk/ewca/civ/2026/282

Moylan, Andrews, and Nugee LJJ. The Court of Appeal dismissed two appeals from a set-aside order made by HHJ Hess sitting as a deputy High Court judge. The court considered issues of material non-disclosure by the Husband, and whether gifts made by the wife’s mother were conditional or made by mistake.

Background

The Husband and Wife married in 1998. H is British, W comes from a very affluent family. The family has been involved with extensive litigation in the past, which has left W estranged. Both H and W held roles within the family company. The couple separated in 2017, and the financial remedy proceedings concluded in March 2022.

There was no sharing claim; the assessment was on a purely needs basis, as there was no marital acquest in relation to W’s wealth. The assets, taken at their highest, amounted to £6.2m. The parties reached an agreement and entered into a consent order: W was to pay a lump sum of £850,000 and school fees, with a recital that she would retain her consultant role within the family business. It was noted that this outcome was far removed from equality, but the court approved the order as needs were met and both parties were legally advised and seemingly content.

W did not pay the lump sum or school fees. H applied for enforcement. W cross-applied, having received slightly less from a specific account than set out in schedules. The parties were ordered to give financial disclosure. H was suddenly very wealthy. This was following receipt of two gifts from W’s parents: AUS$20,000,000 in July 2022, and a further US$20,000,000 in August 2022. W applied to set aside the March 2022 order on the basis of a Barder event or material non-disclosure.

The intervenor, W’s mother, applied to recover gifts made to H, arguing that the gifts were either subject to an implied condition that they were not to benefit W, or were made by mistake. W defended these claims, saying that other gifts made to H or to her siblings were not subject to conditions or vitiated by mistake.

The judgment

Set aside of March 2022 order

W’s set aside application centred on H’s non-disclosure. H accepted he understood his duty of disclosure but contended that his knowledge of a substantial gift from W’s parents only arose after the duty had ended. H and intervenor stated that the July 2022 gift was as a consequence of H being diagnosed with cancer.

The judge rejected this case, finding that H, the intervenor, and their witnesses coordinated their story and were not giving an honest, full and independent account. The judge concluded that H acquired knowledge of this gift, including the likely size of the first tranche, well before March 2022. This necessarily meant that W’s parents had decided to make such a gift by that point. W’s siblings had received gifts of the same size in July 2021. H’s gift matched the 2021 conversion rates from AUD to USD, not those contemporaneous with the July 2022 payment. The judge concluded that the July 2022 gift was therefore a postponed gift from the year before.

The judge set aside the March 2022 consent order on the grounds of material non-disclosure, rejecting H’s submissions that disclosure would have made no material difference.

The judge did not deal with W’s Barder case, as it was unnecessary.

The intervenor’s claims

The judge first decided that the gifts were clearly intended to be outright gifts, with no condition attached. He dismissed arguments that the condition was so obvious it went without saying.

HHJ Hess then considered the mistake claim.

It was the intervenor’s case that she believed the divorce proceedings were concluded, and that this was a relevant factor in her decision to make the gift to H. The belief was mistaken. She argued that this mistake was sufficiently grave to make it unconscionable for H to retain the gift if the consequence was that W could share in it, contrary to the intervenor’s wishes.

However, the judge held that the claim failed at the point of unconscionability: it was difficult to see any rational adverse consequences for the intervenor from H keeping the gift. He therefore dismissed the intervenor’s application.

First appeal (Husband)

H argued that the judge should have found the non-disclosure to be not material. He said the gift should have been foreseen or foreseeable by W, and the court had not addressed how disclosure would have altered the award.

Moylan LJ, giving the lead judgment on this appeal, rejected these submissions. The non-disclosure was deemed to be material because it was deliberate, and therefore the order was correctly set aside unless H could establish the Sharland exception (which applies where non-disclosure was not deliberate). He did not do so. H failed also to discharge the burden for proving lack of materiality. The disclosure would have made a significant difference.

W’s belief that H might have access to undisclosed resources does not exonerate him from providing full and frank disclosure. A party’s asserted belief is not equivalent to admitted fact.

The disclosure would have fundamentally changed the landscape of the case as presented in 2022. The initial order was made on a needs basis, with H’s needs met by an £850,000 award. Had the pot been larger, the needs assessment would have changed, and uncertainties left in the order may have been treated differently.

The Court of Appeal dismissed this appeal.

Second appeal (intervenor)

Two grounds were advanced:

The judge was wrong to dismiss the mistake claim.
The judge was wrong to dismiss the failure of basis claim.

Ground 2: Failure of basis

The case was founded on the contention that the gifts were conditional. Nugee LJ noted that the intervenor’s evidence in cross-examination provided no support for the pleaded case that H could only retain gifts if W did not benefit. The judge was justified in determining that the gifts were made outright.

The intervenor attempted to argue that ‘basis’ was a broader concept than conditionality. This was neither pleaded nor argued before the judge. The judge decided the case as it lay before him, and this cannot therefore be subject to appeal.

Ground 2 was dismissed.

Ground 1: Mistake

The claim relied on the equitable jurisdiction to set aside a voluntary transaction for a sufficiently serious mistake.

Nugee LJ, giving lead judgment in this appeal, reiterated the principles:

The mistake must be so serious as to make it unjust for the donee to retain the property.
Mistake is different from mere ignorance and misprediction.
Carelessness does not matter unless the circumstances show the donor deliberately ran the risk of being wrong.

The gravity of the mistake is central to the assessment of unconscionability.

The intervenor’s alleged mistaken belief was twofold:

that the consent order was the end of the matter; and
that W could not benefit from the gifts.

After reviewing the evidence and findings of HHJ Hess, Nugee LJ concluded:

The intervenor believed in March 2022 that once the financial remedy order was sealed, W could make no further claim.
The gift was not made in March 2022 because H asked for it to be deferred.
In June 2022, H was diagnosed with cancer, causing the Intervenor and her late husband to make the gift.

However, this did not demonstrate that the intervenor: