A process which arises in matrimonial and civil partnership finance litigation, by which assets which may have started as non-matrimonial property (NMP) (ie attributable only to one party) become, over the course of a relationship, matrimonial property (MP).
NMP is generally is not expected to be shared (as in Standish v Standish [2025] UKSC 26, [2025] 3 WLR 155) and remains subject to any needs or compensation argument by a claimant spouse or civil partner.
The word, new to the lawyer’s lexicon, was apparently coined by of Roberts J in WX v HX [2021] EWFC 14 at [121]:
“What, then, should be the court’s approach to H’s case that W’s separate funds should be treated as having been ‘matrimonialised’ as a result of the significant contribution he has made over and above his role as the family’s breadwinner.”
In Standish v Standish, the court said, at para 54:
“it is the parties’ treatment of what was initially non-matrimonial property, over time, as shared between them, that is central in deciding the fairness of that property being viewed as matrimonialised.”