In Lassnig v Zhou [2025] NZSC 116 the Supreme Court has ruled on the extent to which a trust settled by a couple in a short-term relationship should be modified under s 182 of the Family Proceedings 1980 Act when their relationship ended.

There were no children of the marriage but each party had a child from an earlier relationship.

The Supreme Court has wanted litigants in s 182 claims to calculate the extent to which a trust should be modified by reference to a diagrammatic formula involving factors “A”, “B” and “C”. But the application of that model has been unpredictable, as is evident from Lassnig itself, where the Family Court, High Court and Court of Appeal differed dramatically in their views of what the financial outcome should be.