This guide is the fourth in a series of supplements to the main guidance document in the UNITAR Guidance Series for Implementing a National PRTR Design Project (2018). The guidance series provides countries with a suggested step-wise approach for undertaking the design of a national PRTR system. The documents in this series provide in-depth guidance on UNITAR’s suggested approach for implementing a national PRTR design project. The guidance is not meant to be prescriptive and should be adapted by countries in a flexible manner according to their specific needs and circumstances.