The millionaire’s defence is not available simply because someone is wealthy. Several conditions must typically be met before a court will permit limited disclosure.

Exceptional wealth is required. Despite its name, the millionaire’s defence would not succeed for most millionaires. The level of wealth must be so substantial that there is genuinely no prospect of the court ordering a sum the paying party could not meet. Cases where it has succeeded have typically involved individuals with assets in the tens or hundreds of millions of pounds.

The sharing principle should not apply. In most divorce cases, the court’s starting point is that matrimonial assets should be shared equally between the spouses. Where the sharing principle applies, the court needs to know the full extent of the assets to divide them fairly. The millionaire’s defence is therefore most commonly deployed where assets are predominantly non-matrimonial (acquired before the marriage or by inheritance) and the claim is limited to meeting the financially weaker party’s needs.

Security must be available. A party cannot simply assert they are wealthy and expect the court to take their word for it. There must be sufficient assets within reach to provide security for any ongoing maintenance payments. If assets are illiquid or held overseas with no mechanism for enforcement, the millionaire’s defence may not succeed.

The Court of Appeal has expressly disapproved of the millionaire’s defence in most matrimonial proceedings. The landmark case of White v White [2000] established that both spouses are generally entitled to an equal share of matrimonial assets. This principle requires full financial disclosure so the court can determine what is fair. 

However, there is a narrow category of divorce cases where the millionaire’s defence may apply. In AH v PH [2013] EWHC 3873 (Fam), the parties had a short marriage of approximately four and a half years. The husband’s assets of £76 million were entirely non-matrimonial, having been accumulated before the marriage. The judge held that since the case did not involve sharing matrimonial assets—but rather assessing the wife’s needs—the husband could provide a broad outline of his wealth rather than full disclosure.

This remains an exceptional approach. In most divorces, particularly longer marriages where wealth has been accumulated during the relationship, full disclosure through Form E and supporting documentation will be required regardless of the parties’ wealth, and clients should remain informed at every stage of the proceedings.

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The millionaire’s defence is more commonly deployed in claims under Schedule 1 of the Children Act 1989. These are claims for financial provision for children whose parents were never married (or whose marriage is not recognised under English law, such as a Nikah ceremony without civil registration).

Unlike divorce proceedings, Schedule 1 claims are based solely on the child’s needs. There is no sharing principle. The court assesses what the child requires for housing, education, maintenance and other capital needs across different aspects of the child’s life, having regard to the paying parent’s resources and standard of living. Because the focus is on needs rather than entitlement to a share of assets, there is greater scope for the millionaire’s defence to apply.

The leading modern authority is Y v Z (Schedule 1) [2024] EWFC 4, where the father was a member of a Middle Eastern royal family. He accepted that he had “the liquidity and resources to meet any reasonable orders that may be made by the court for the benefit of the children.” Mr Justice Peel accepted the millionaire’s defence in principle but held that some disclosure was still necessary.

Peel J identified four reasons why limited disclosure remains important even where the millionaire’s defence applies:

1. Understanding the scale of wealth – The court and the other party need some understanding of the overall picture and how wealth is structured.
2. Assessing what is realistic – The nature of the wealth affects what orders are practical. Illiquid assets cannot easily fund immediate payments.
3. Providing security – Where ongoing maintenance is ordered, there must be sufficient assets to secure those payments.
4. Informing the budget – The court must make decisions about what is reasonable in a child’s budget, based partly on the paying parent’s wealth and standard of life.

The judge ordered the father to complete a Form E but without the usual requirement for supporting documentation, plus a narrative explanation of non-standard assets such as trusts. The father ultimately disclosed net assets of approximately £111 million.

Recent Developments: MH v FD [2025]

The October 2025 judgment in MH v FD [2025] EWFC 390 provides important modern guidance on the millionaire’s defence. The case involved a high-profile entrepreneur father who accepted he was “very wealthy” and could meet any order the court might make. Despite this, he had paid only one term of nursery fees since the child’s birth and had made no other financial contribution.

Mr Justin Warshaw KC, sitting as a Deputy High Court Judge, provided a clear explanation of the millionaire’s defence:

“This is not a defence against the disclosure of resources. Such disclosure must always be made, albeit in attenuated form, as the court is mandated under section 4(1) to consider those resources when exercising its powers. It is, rather, a defence against the discovery of documents and the interrogation of assertions made through disclosure.”

The judgment emphasises that the millionaire’s defence is not a mechanism to avoid responsibility—merely a way to limit unnecessary litigation costs where means are genuinely not in dispute. A wealthy parent cannot use it as a shield against providing any support for their child.

Even where the millionaire’s defence succeeds, disclosure is never eliminated entirely, and proper representation with legal expertise is still needed to manage that process. At minimum, the paying party will typically be required:

• Complete a Form E or equivalent financial statement
• Provide a narrative explanation of complex assets (trusts, business interests, overseas holdings)
• Confirm their ability to meet any reasonable order
• Demonstrate sufficient assets to provide security for ongoing payments

What is dispensed with is the detailed documentation that would normally accompany Form E: twelve months of bank statements for every account, business accounts, property valuations, pension valuations, and so on. The forensic analysis of whether disclosed figures are accurate is also curtailed.

If your former partner is attempting to run the millionaire’s defence, the right advice can assist you in assessing your situation, and you are not without recourse. The court will only permit limited disclosure where it is genuinely satisfied that full disclosure is unnecessary. You may be able to challenge the defence if:

• You have grounds to believe your former partner’s wealth is less than claimed
• Assets are illiquid or difficult to access, making security problematic
• Your former partner has connections overseas that create enforcement risks
• There are specific assets you believe should be disclosed (trusts, business interests, property)

The court can draw adverse inferences from a party’s failure to provide adequate disclosure. In Y v Z, the mother argued that the father’s actual assets significantly exceeded what he had initially indicated—and she was proved right when his Form E disclosed £111 million rather than the £70 million previously mentioned.

For those considering or facing a millionaire’s defence argument, the practical implications include:

For the party running the defence: You will still need to provide meaningful disclosure, even if not the full documentation. Attempting to avoid all disclosure is likely to fail and may damage your credibility with the court. The defence works best when combined with a constructive approach to settlement.

For the party opposing the defence: Do not assume you cannot challenge inadequate disclosure. If you have genuine concerns about hidden assets, enforcement, or the adequacy of proposed security, raise these clearly with the court. The burden is on the wealthy party to demonstrate that limited disclosure is appropriate.

For both parties: The millionaire’s defence should ultimately reduce costs and delay, while helping the court and the parties focus on the best possible outcomes. Fighting over disclosure when the outcome will not materially change is rarely in anyone’s interest. However, the defence must not be used to achieve an unfair outcome by concealing the true picture.

The millionaire’s defence is a sophisticated legal strategy that requires expert handling. Whether you are considering running the defence or believe your former partner is using it inappropriately, specialist family law advice is essential.

Our family law team has extensive experience advising high net worth individuals on financial disclosure and the millionaire’s defence. We can help you understand your options and develop a strategy that protects your interests.