What is the difference between CGST, SGST, and IGST on an Indian GST invoice?

For intra-state sales (within the same state), GST is split equally into CGST (Central GST) and SGST (State GST). For inter-state sales (between different states), the full rate is charged as IGST (Integrated GST).

Why are HSN and SAC codes required on Indian GST invoices?

HSN (Harmonized System of Nomenclature) codes classify goods, and SAC (Services Accounting Code) codes classify services, enabling standardized tax rate assignment across India.

What is the 15-digit GSTIN structure on an Indian invoice?

GSTIN contains state code (first 2 digits), PAN number (next 10 digits), entity number (13th digit), default 'Z' (14th digit), and check digit (15th digit).

India GST Invoicing: CGST+SGST vs IGST & HSN Codes

Format GST invoices under India tax law. Separate intra-state (CGST+SGST) from inter-state (IGST) supplies and list HSN/SAC codes.

India GST Invoice — CGST, SGST, IGST & HSN/SAC Codes

Businesses in India must format invoices under GST laws, distinguishing intra-state sales (CGST + SGST) from inter-state supplies (IGST). Including 15-digit GSTINs and correct HSN or SAC classification codes is mandatory.

Set up multi-tier GST rate splits (CGST + SGST for intra-state, IGST for inter-state) and export ready-to-print PDF tax invoices with HSN/SAC code columns.

Authoritative Sources

GST Council — Invoice rules under GST — GST Council of India

Written by the Invio Team — invoicing tools built for freelancers and small businesses worldwide

Last updated: July 2026

This guide is for informational purposes only. For tax or legal advice specific to your jurisdiction, consult a qualified accountant or tax professional.