One of the hottest topics in family law over the past year has been the concept of matrimonialisation. It sounds technical, but the principle is surprisingly simple.

If one spouse brings valuable assets into a marriage, do those assets always remain theirs? Or can they, over time, become part of the matrimonial pot to be shared equally on divorce?

A recent decision of Recorder Christopher Stirling in BC v BC (No. 2) [2026] EWFC 37 provides one of the clearest examples yet of how the courts are applying the Supreme Court's landmark decision in Standish v Standish.

The answer, perhaps unsurprisingly, is that it depends on what the parties did with the asset during the marriage.

What Is Matrimonialisation?

Not every asset owned by a husband or wife is automatically shared equally on divorce.

Generally speaking:

• matrimonial assets—those built up during the relationship through the parties' joint endeavours—are normally shared equally; and
• non-matrimonial assets, such as wealth acquired before the relationship, by inheritance or by gift, may justify a different approach.

The difficult question is what happens when an asset starts life as non-matrimonial but is used extensively for the benefit of the family.

That is where matrimonialisation comes in.

The Shares That Changed Character

In BC v BC, the husband owned valuable company shares before the parties' relationship reached the stage of cohabitation akin to marriage. They were therefore clearly non-matrimonial property at the outset.

Years later, however, the position looked very different.

Rather than keeping those shares separate, the husband borrowed millions of pounds against them. Those funds were paid into the parties' joint bank account and used to acquire and renovate family properties, fund their lifestyle and meet joint expenditure.

The judge concluded that, by this stage, the original non-matrimonial character of the shares had been lost. The shares had become, in his words, "well and truly matrimonialised."

What Does Standish Mean in Practice?

The Supreme Court in Standish explained that matrimonialisation depends on how the parties have treated an asset over time.

It is not simply a question of who originally owned it. Recorder Stirling adopted that approach, observing that matrimonialisation rests on the parties treating the asset as a shared resource. Here, the value generated by the husband's shares had been used to purchase jointly owned property and finance the family's life together.

That made all the difference.

No Halfway House

Perhaps the most interesting part of the judgment comes next.

The husband accepted that the shares had, to some extent, become matrimonial. However, he argued that their original source should still justify him receiving a slightly larger share—around 55% rather than an equal division.

The judge rejected that submission. He held that once an asset has become matrimonialised, there is generally no room for a hybrid approach. Either the asset remains non-matrimonial, or it has become matrimonial and falls to be shared under the ordinary sharing principle. There was no principled basis for awarding the husband an extra five per cent simply because the shares had originally belonged to him.

For practitioners, that may prove to be one of the most significant aspects of the decision.

It's Not Just About Ownership

The case is a reminder that family courts look beyond legal title. What matters is how assets have been treated throughout the relationship. An inheritance invested in the family home. Business wealth used to buy jointly owned properties. Savings placed into joint accounts.

These are all examples of circumstances in which originally non-matrimonial property may gradually lose its separate identity.

Other Interesting Features

The judgment also contains several practical points.

First, the court carefully analysed when cohabitation akin to marriage actually began, rejecting the argument that simply spending increasing amounts of time together was enough. Instead, the judge looked for objective markers such as purchasing a home together, opening joint bank accounts and becoming financially interdependent.

Secondly, despite the family's very substantial wealth, the court adopted a pragmatic approach to liquidity. Rather than allowing valuable overseas properties to be retained, it ordered their sale to ensure a significant anticipated HMRC liability could be met and to avoid future litigation over payment of the tax debt.

Finally, the judge favoured transferring company shares directly to the wife, protected by conventional "drag and tag" provisions, rather than leaving the parties financially tied together through a complex web of deferred payments, undertakings and continuing obligations. The court preferred a clean, workable solution over one likely to generate further disputes.

What Does This Mean for Couples?

For anyone entering a marriage with existing wealth, BC v BC contains an important lesson. Simply owning an asset before the relationship does not guarantee that it will remain separate forever. If it is repeatedly used as a family resource, invested into joint property or relied upon to support the marital partnership, the court may conclude that it has become matrimonial property capable of equal sharing.

That does not mean every pre-marital asset will automatically be divided equally. Far from it. But after Standish and now BC v BC, the focus is increasingly on how the parties have treated the asset during the relationship, rather than simply where it came from.

Final Thoughts

The law on matrimonialisation is becoming clearer. Standish provided the framework. BC v BC demonstrates how that framework works in practice.

For separating couples, the message is straightforward: the history of an asset is important, but so too is its journey. An asset that begins life as "mine" can, over the course of a long marriage, become "ours".

Understanding where that line is drawn can make a difference worth millions of pounds.