This Safety Guide describes how the licensing process should be applied at the various stages of the lifetime of a nuclear installation, with discussion of topics and required documents to be considered at each stage. Recommendations on the application by a regulatory body of a graded approach in the licensing process are also provided. It also describes the processes that should be undertaken to meet the regulatory and legal requirements in a Member State to authorize the establishment of a nuclear installation and/or initiation of its activities. While this Safety Guide focuses on safety at nuclear installations, it is noted that integration of safety and security aspects should be considered and evaluated by the regulatory body in the licensing process.