Matrimonialisation in Common Law: Standish and LKW v DD
Family Law
“…despite the temptation to ‘never say never’”, “the time has come to make clear that non-matrimonial property should not be subject to the sharing principle”
“Although this has not previously been clearly spelt out … matrimonialisation rests on the parties, over time, treating the asset as shared”
The UK Supreme Court (“UKSC”) delivered a significant ruling on ancillary relief in Standish v Standish [2025] UKSC 26, providing a definitive view on the considerations and implications of whether property is matrimonial — issues that resonate with, and will have jurisprudential interaction with, the principles established in Hong Kong’s LKW v DD [2010] 13 HKCFAR 537.
Matrimonial property vs. Non-matrimonial property
In LKW v DD, the Court of Final Appeal (“CFA”) recognised that there is an important distinction between matrimonial property and non-matrimonial property [87]. The importance of this distinction cannot be overstated, as assets found to be “non-matrimonial” in nature would be excluded from the application of the sharing principle [87]-[88]. This distinction is conceptually important and similarly formed the starting point in Standish.
The CFA also recognised that there are at least 2 types of property which may be characterised as non-matrimonial on the basis of source: (a) property acquired during the marriage by one of the parties from a source wholly external to the marriage (e.g.by gift or inheritance), and (b) assets derived from a business or an investment conducted solely by one party” [89].
Nonetheless, non-matrimonial property is not automatically ringfenced once it is identified as such. The UKSC stated that non-matrimonial property can still be subject to the principle of needs (i.e., the relationship has generated needs which it is right that the other party should meet) and the principle of compensation (i.e., compensation may be available for relationship-generated disadvantage) [48]. This approach on needs has its counterpart in LKW v DD. The CFA noted that the exercise “often stops” at “needs”: the court considers what are the net assets of the parties (regardless of source), and where the available assets are insufficient to provide for both parties, the Court’s approach is to simply stretch as far as possible all those finite resources to meet the parties’ needs [54]. Only where there are surplus assets, does the question of “ought it be shared” arise.
What did the UK Supreme Court decide?
In practice, however, litigants have continued to struggle with whether (and, if so, how) non-matrimonial property might be said to have transformed into matrimonial property, especially in long marriages.
This is the question addressed by the UKSC in Standish, where H entered into a 15-year marriage with considerable wealth. At issue was H’s transfer of £80 million to W in 2017, just three years before the marriage broke down. The transfer was originally intended to be placed on offshore trusts for their children, thereby negating inheritance tax, though W continued to keep the funds in her sole name [19]-[23].
The lower courts were in disagreement: at first instance, the High Court found that such assets had transformed into matrimonial property and were subject to sharing but catered for the non-marital source of the assets by applying a 60/40 division in favour of H [25]. The Court of Appeal allowed H’s cross appeal and held on the question of matrimonialisation, that the source of an asset is the critical factor, not the legal title [25].
The UKSC, adopting for the first time at the highest court level the term “matrimonialisation” [51]-[55], upheld the CA’s decision, holding that it would be contrary to the sharing principle if legal title is to be used as the determinative factor [47]-[49].
Legal test for “matrimonialisation” of non-matrimonial property
Under the UKSC’s formulation, the crucial question for the Court deciding whether an asset has been matrimonialised is: “how the parties have been dealing with the asset and whether this shows that, over time, they have been treating the asset as shared between them. That is, matrimonialisation rests on the parties, over time, treating the asset as shared” [51]-[55].
The UKSC also definitively closed the door to cases of sharing in non-matrimonial property. Such cases had been described in lower courts as being “as rare as a white leopard”. After Standish, the UK has ruled out the possibility of such cases of sharing: “despite the temptation to ‘never say never’, … the distinction between matrimonial and non-matrimonial property becomes largely meaningless if the sharing principle applies to the latter as well as the former.”
Applying the principle to the facts, the UKSC held that the transfer between H and W was designed to save tax. It did not show that the asset has been treated as shared between the parties, and therefore did not amount to matrimonialisation [56]-[63].
Examples of Matrimonialisation
The UKSC expressly agreed with Wilson LJ’s analysis in K v L [2011] EWCA Civ 550, particularly the three possible situations, albeit non-exhaustive, where matrimonialisation of non-matrimonial property may occur [51]:
(a) Over time matrimonial property of such value has been acquired as to diminish the significance of the initial contribution by one spouse of non-matrimonial property.
(b) Over time the non-matrimonial property initially contributed has been mixed with matrimonial property in circumstances in which the contributor may be said to have accepted that it should be treated as matrimonial property or in which, at any rate, the task of identifying its current value is too difficult. In Hong Kong, the courts have similarly considered arguments on the mixing of non-matrimonial property, and has often referred to this as “intermingling”: LWH v YMT (Financial Provision for Family and Dependants) [2023] 1 HKLRD 1004, [158] (on a “notational divorce” inquiry); RBP v CFB [2024] HKFC 84, [221]; LPM v LKH [2022] HKFC 214 [43].
(c) The contributor of non-matrimonial property has chosen to invest it in the purchase of a matrimonial home which, although vested in his or her sole name, has — as in most cases one would expect — come over time to be treated by the parties as a central item of matrimonial property. The centrality of the matrimonial home to the marriage, and thus an asset for sharing regardless of source, similarly featured in LKW v DD [98].
The phrase “over time”, which appears in all three situations, means that the period of time must be sufficiently long for the parties’ treatment of the asset as shared to be regarded as settled [52].
Notably, even though the first situation does not necessarily rest on the treatment of assets by both parties, the UKSC confirmed that it is nevertheless fair and pragmatic. It reasoned that, where the matrimonial property is so much greater than the non-matrimonial property that it is “not worth the candle”, it is unfair to the parties to incur needless expenses in trying to work out what percentage was non-matrimonial [55].
An additional justification for the first situation to apply is that the percentage of purported non-matrimonial assets is not sufficiently significant to justify extensive evidential investigation and/or an other than equal division of the wealth [55]. Practitioners are therefore reminded to pay attention to the relative size of the non-matrimonial assets and not to expend a disproportionate amount of costs on unnecessary investigation.
Conclusion
The decision in Standish is one of wide-reaching jurisprudential value. Adopting the term of “matrimonialisation” for the first time in the highest level in the UK, it offers much-needed clarity on the doctrine. By setting out the key determinant of whether an asset has been matrimonialised (namely, the parties’ intentions and treatment of such assets over time), and by closing the door to arguments of sharing of non-matrimonial assets, the UKSC has drawn a clear boundary around the scope of the sharing principle.
Non-matrimonial property can still be subject to the principle of needs and the principle of compensation [48]. Nevertheless, the interplay between non-matrimonial assets and the principles of needs and compensation remains to be clarified in future cases.
The UKSC’s approach will be of jurisprudential value to jurisdictions like Hong Kong, where LKW v DD laid the groundwork for similar distinctions but left open the question of transformation through conduct.
Authors: Isabel Tam, Ted Chan.
Isabel Tam
Recognised as Leading Junior in Legal 500 (2025, Administrative and Public Law), Isabel’s practice focuses on family law, public law, and regulatory matters. She has extensive experience in general matrimonial finance and preservation of assets, as well as particular expertise in complex legal issues arising out of LGBTQ/modern families and the dissolution of families with cross-border elements. She has acted as sole counsel in the Court of Appeal, Court of First Instance, District Court, Magistrates’ Courts, and the Court of Final Appeal.
Isabel has been involved in landmark family law cases concerning modern families and LGBTQ rights in Hong Kong. Notably, she represented the non-biological parent in AA v BB [2021] 2 HKLRD 1225, securing guardianship and joint custody for a same-sex couple. She was involved in NF v R [2023] 5 HKLRD 58, a case resulting in a novel type of relief, a declaration of “parentage at common law” for a same-sex parent. Her expertise in family law is augmented by her experience in other related areas including in particular tax (Koo Ming Kown & Anor v The Commissioner of Inland Revenue [2021] 3 HKLRD 642 on liability for additional tax), mental incapacitated persons, and trust claims.
She is a contributor to the current editions of Hong Kong Civil Procedure and Bullen & Leake & Jacob’s Hong Kong Precedents of Pleadings.
Please visit Isabel’s profile for more details.
Ted Chan
Formerly a Judicial Assistant of the Court of Final Appeal, Ted Chan has a broad civil and criminal practice with regular instructions in family law, probate, and mental health cases. Ted regularly advises on and handles matrimonial and family cases, including ancillary relief, custody, abduction, relocation applications, forum disputes, etc.He is a CEDR-accredited mediator and frequently engaged in mediations involving matrimonial disputes among other civil and commercial matters.
Outside his legal practice, he is a Faculty Member of the Asian Academy of Family Therapy, and regularly participates in multi-disciplinary exchanges with the medical and social welfare professions, addressing family law issues.
More details can be found in Ted’s profile.
This article was first published on 16 July 2025.
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