Effective enforcement is key to ensuring a functional planning system, but the legal provisions can be complex. Recent statutory changes have modified long-standing rules around enforcement time limits and other key enforcement functions while, in May 2024, the Court of Appeal handed down judgment in the case of Caldwell, providing guidance on the application of the Murfitt principle. Anna Stein and Daniel Henderson discuss the various changes, and consider the impact that they will have on the field of planning enforcement.