Martin Davis, 33 Bedford RowMatrimonialisation—the process of converting non-matrimonial assets into matrimonial property—remains one of the most intricate and contested areas in family law. Recent landmark decisions, notably Standish v Standish, have brought much-needed clarity to this nuanced concept. The Supreme Court’s definitive ruling in Standish v Standish [2025] affirmed this cautious approach, confirming that non-matrimonial assets retain their character unless clearly integrated into the marital finances. This article examines why matrimonialisation cases are so challenging to resolve, balancing the needs of fairness and asset protection. It provides a thoughtful analysis of evolving legal principles and recent case law, offering valuable insight for practitioners and clients navigating the complexities of high-net-worth divorce settlements.