In the context of the European Environmental Noise Directive 2002/49/EC (END) the European Commission decided to prepare Common NOise aSSessment methOdS (CNOSSOS-EU) for road, railway, aircraft and industrial noise. An integral part of CNOSSOS-EU is the provision of guidelines on the correct interpretation of the calculation methodology, the implementation of the algorithms and the appropriate use of the methods on the basis of data availability. In this paper, the focus will be on the use of the guidelines in the application of CNOSSOS-EU for the purpose of strategic noise mapping, as required by the END, and will include considerations about the expected accuracy of the calculations performed. This paper completes the full description of the method given by Part I (roadmap) and Part II (methodology) in the same Conference.JRC.I.1-Chemical Assessment and Testin