On a sale where the supplier and the place of supply are in the same state, GST is split into two equal parts: CGST, which goes to the central government, and SGST, which goes to the state. An 18% item is billed at 9% CGST and 9% SGST.
A worked example
A plumbing store in Ahmedabad sells 40 CP taps at ₹400 to a contractor in Ahmedabad:
| Line | Amount |
|---|---|
| Taxable value | ₹16,000 |
| CGST 9% | ₹1,440 |
| SGST 9% | ₹1,440 |
| Total | ₹18,880 |
Using CGST credit
Credit of CGST you paid on purchases can be used to pay CGST and then IGST. It cannot be used to pay SGST. In practice, credit is used in a set order: IGST credit first, then CGST and SGST.
Rates
Since 22 September 2025 most goods and services fall in two main slabs, 5% and 18%, with 40% for a short list of luxury and sin goods (as of October 2026). Each is split equally between CGST and SGST on sales within the state.
MatruOS reads both states and splits the tax on each invoice.