This document provides guidance on implementing Central Sales Tax (CST) in Tally.ERP 9. It discusses CST basics, registration requirements, declaration forms used for CST transactions, and how to file CST returns. It then provides lessons on enabling CST in Tally.ERP 9, processing various CST transaction types like inter-state purchases and sales, accounting for CST adjustments and payments, and generating CST reports. The document aims to help users comply with CST regulations using Tally.ERP 9's features.