SGST (State GST)
The state government's half of the GST on a sale made within your own state, charged alongside CGST at the same rate.
SGST is the state's share of GST on an intra-state supply. It is always paired with CGST, each at half the total rate, and it goes to the state where the supply is treated as taking place.
UTGST, the near-identical cousin
In Union Territories without their own legislature, UTGST takes the place of SGST. Same idea, same rate, different statute. Your invoice format has to carry whichever applies.
Why the pairing is fixed
You never see SGST alone. If a supply is intra-state you charge both halves; if it is inter-state you charge IGST only. An invoice with SGST but no CGST is an error, not a variation.
The credit pools stay separate
SGST credit can be used against SGST and, in a defined order, against IGST — but not against CGST. Getting the components wrong on a document therefore does more than look untidy; it puts the credit in the wrong pool for both you and your buyer.
How KillStock handles it
Place of supply drives the split on every invoice, and the GST summary and GST returns reports show CGST, SGST and IGST separately so the figures you file match the documents you issued.
A common mistake
Assuming the customer's billing address decides the split. It is the place of supply that decides, and for goods that is usually where the movement of the goods ends.