What is the difference between CGST, SGST, and IGST?

CGST and SGST apply on intra-state sales (supply inside one state). IGST applies on inter-state sales (supply between two states, and certain other cases such as imports as the law provides). That is the core difference.

On a normal taxable intra-state sale you charge CGST + SGST (often equal halves of the total GST rate). On a normal taxable inter-state sale you charge IGST at the full rate instead — not CGST+SGST on that same line.

Quick definitions

• CGST — Central Goods and Services Tax, collected by the Central Government on an eligible intra-state supply
• SGST — State Goods and Services Tax, collected by the State Government on that same intra-state supply (UTGST applies in Union Territories in place of SGST where the law says so)
• IGST — Integrated Goods and Services Tax, collected on inter-state supplies (and other cases the statute names, such as imports)

Indian examples

Intra-state: A shop in Maharashtra sells taxable goods to a customer in Maharashtra. The invoice shows CGST and SGST for that line (for example at 18% GST overall, typically 9% CGST + 9% SGST — confirm the rate that applies to your HSN/SAC).

Inter-state: The same Maharashtra shop sells to a customer in Gujarat. The invoice shows IGST for that line (for example 18% IGST), not a CGST+SGST split on the same taxable value.

Place of supply rules decide which case applies. For goods, delivery location often matters; for services the rules are more detailed. Do not invent thresholds or rates — use the rate notified for your supply and ask a chartered accountant for edge cases.

Official GST basis

GST structure and tax types are set out under the CGST Act, IGST Act, and related rules. For current law, notifications, and portal guidance, use official sources such as gst.gov.in and cbic-gst.gov.in. This article is an explainer for Indian MSMEs, not a substitute for professional tax advice or the latest notification.

Why the split matters on the invoice

Input tax credit (ITC) depends on the tax type charged and the buyer’s eligibility. Wrong tax type (for example IGST when the supply was intra-state) creates return and credit-matching problems. Billing software should pick CGST+SGST vs IGST from your business state and the party’s place of supply once masters are set.

What to put on the invoice

• Correct place of supply
• Either CGST+SGST lines or IGST — not both for the same taxable line in normal cases
• Correct rate as per HSN/SAC

What to do next

When you need to raise one GST invoice now, use the GST invoice generator. For ongoing GST billing software for Indian MSMEs, see Billoxy.