The law on consent - the duty of a healthcare professional to advise a patient on the risks of a particular treatment - has evolved over the years. However, the legal test was clarified by the Supreme Court in the case of Montgomery v Lanarkshire Health Board [2015] UKSC 11. It is essential that all healthcare professionals/beauticians/therapists are aware of, and understand, the practical implications of this very important judgment. This guidance note has therefore been prepared to help practitioners understand what the legal test says and how to comply with this in practice.