SGST is the state's half of GST on a sale made within the state. It is charged at the same rate as CGST: an item at 5% carries 2.5% CGST and 2.5% SGST. In union territories without their own legislature, such as Chandigarh or Ladakh, UTGST takes its place.
Using SGST credit
SGST paid on purchases can be used to pay SGST and then IGST. It can never be used to pay CGST, and the reverse is also true. This is why a business with a lot of SGST credit and little SGST to pay may see credit build up while it still pays CGST in cash.
When SGST is wrong
If you charge CGST and SGST on what was in fact an inter-state sale, the tax has gone to the wrong place. The fix is to pay IGST and claim a refund of the CGST and SGST, which takes time. A buyer's GSTIN that starts with a different state code is the simplest warning sign.
On the invoice
CGST and SGST are shown as separate lines with their rates and amounts. A Gujarat tile dealer selling a box of 600x600 mm vitrified tiles at ₹720 within Gujarat shows ₹64.80 CGST and ₹64.80 SGST.