HSN code (4-digit) for Goods and Services Accounting Codes (SAC) for Services must be compulsorily mentioned by all taxpayers with turnover in the preceding financial year above Rs. 5 Crore (For the first year of operations of GST, self-declaration of turnover of previous financial year will be taken as the basis as all India turnover data will not be available in the first year. From the 2nd year onwards, turnover of previous financial year under GST will be used for satisfying this condition.For taxpayers with turnover between Rs. 1.5 Crores and Rs. 5 Crores in the preceding financial year, HSN codes may be specified only at 2-digit chapter level as an optional exercise to start with. From second year of GST operations, mentioning 2-digit chapter level HSN Code will be mandatory for all taxpayers with turnover in previous financial year between Rs. 1.5 Crores and Rs. 5.0 Crores.All taxpayers, irrespective of his turnover, can use HSN code at 6-digit or 8-digit level if desired.To start with, compounding dealers may not be required to specify HSN at 2 digit level also.HSN Codes at 8-digit level and Accounting Codes for services will be mandatory in case of exports and imports.The taxpayers who have turnover below the limit of Rs. 1.5 Crore will have to mention the description of goods/service, as the case may be, wherever applicable. In order to differentiate between the HSN code and the Service Accounting Code (SAC), goods will be denoted by G and services will be denoted by S.Click here to find HSN code and GST rate for all goods and services.