What is the “Green Book” in relation to ACH?

The "Green Book" refers to a comprehensive manual published by Nacha that offers detailed guidance on ACH (Automated Clearing House) operations and compliance. This manual serves as an essential resource for financial institutions, businesses, and organizations involved in ACH transactions. It covers a wide range of topics, including rules, procedures, standards, and best practices for effectively managing ACH payments. Being well-versed in the information contained in the Green Book is crucial for compliance with regulatory requirements and for the smooth processing of ACH transactions, making it a key tool for anyone operating in this space.