This TECDOC was developed under the Regulatory Track of the Nuclear Harmonization and Standardization Initiative (NHSI) and presents a structured process for conducting multinational, pre-licensing joint regulatory reviews of small modular reactor (SMR) and advanced reactor designs. It serves as a valuable resource for regulatory authorities, technical support organizations, reactor vendors, and other industry stakeholders involved in the pre-licensing and licensing of advanced reactors. By facilitating coordinated multinational reviews, the process enables the early identification of potential design-related challenges, reduces the risk of design modifications arising from divergent national regulatory requirements, and improves the overall efficiency of regulatory review processes worldwide. The application of this process supports the harmonization of regulatory practices and contributes to the safe and secure global deployment of advanced reactor technologies.