This regulatory document sets out requirements and guidance for reports and notifications that licensees of waste nuclear substances, Class II nuclear facilities and users of prescribed equipment, nuclear substances and radiation devices must submit to the Canadian Nuclear Safety Commission (CNSC). This document also presents the types of reports and the applicable timeframe for reporting. Licensees and those who transport nuclear substances are required to report to the CNSC regarding situations, events and dangerous occurrences. Regulatory document REGDOC-3.1.3 incorporates and clarifies requirements found in the Nuclear Safety and Control Act (NSCA) and regulations made under the NSCA, including requirements for content and timing of reports. Additionally, it provides guidance on the interpretation and scope of application of these requirements in the context of Class II nuclear facilities, nuclear substances and radiation devicesand waste nuclear substance licensees. Further to the reporting requirements set by the NSCA and the regulations, a licence may contain any term or condition that identifies a reporting requirement and the time frame for submitting the report. This document provides guidance on these licence conditions, including the submission of an annual compliance report (ACR).