IUCLID (International Uniform Chemical Information Database) is a software application designed to record, store, maintain and exchange data on chemicals. It is a key software application for both regulatory bodies and the chemical industry where it is used in the implementation of various regulatory programmes. IUCLID can be customised and configured to manage chemical data in different contexts and is a platform employing globally harmonised data elements pertinent to chemicals. It is continuously updated to provide greater customisation, extension and integration with other tools. This third edition provides the latest updates on IUCLID features and processes, including the use of PostgreSQL, an updated matrix view of the use of IUCLID in OECD countries, the new release schedule, and information on new tools to support the use of IUCLID (Data Uploader) and the IUCLID Customisation Forum.