What is the full form of CST? - Central Standard Time - Central Standard Time (CST) is the Central Time Zone of the United States of America. CST is 6 hours Through this amendment, facility of inter-State purchases by Government Departments at concessional CST rate, against Form-D has been withdrawn. After this amendment, the rate of CST on inter-State sales to Government will be same as VAT/ State sales tax rate. Central Sales Tax (CST) is a tax on sales of goods levied by the Central Government of India. CST is applicable only in the case of inter-state sales and not on sales made within the state or import/export of sales. Inter-state sale is when a sale or purchase constitutes movement of goods from one state to another. CST can mean Central Sales Tax, an indirect tax on inter-state transactions in India, or Central Standard Time, a time zone in North and Central America. Learn the definitions, exemptions, and examples of CST in different contexts.