This article addresses the questions of when mental health advance planning documents are created, the points when circumstances which they are intended to address arise and what consequences should flow when such a situation does arise. It addresses these points primarily from the perspective of what the law could/should be at a conceptual level. It looks at three stages: (a) creation of the document; (b) the period between the creation of the document and the point at which the intended circumstances arise; and (c) the point at which the intended circumstances arise. It does not purport to provide solutions at each stage, but rather to frame the dilemmas to aid discussion. In similar vein, it draws upon case studies from England & Wales, not to purport to dictate similarities of approach, but to flesh out dilemmas that have arisen to stimulate consideration.