The “Good Practice Structured Program for REACH/CLP and SEVESO III Inspections” is a standard Guideline describing the requirements necessary, that inspection authorities should attend to, in order to fulfill their inspection mission adequately, eliminating errors and oversights. This Guideline offers an in depth analysis of all “Inspection System Stages” that ensure the appropriate resources and prerequisites for a competent preparation and execution of inspections, drawing intelligence from the ISO Standards 17020, 14001 and 45001.