GST Invoice Generator
Generate a professional GST-compliant invoice and download as PDF instantly. Supports multiple line items with different GST rates, HSN/SAC codes, intra-state (CGST+SGST) or inter-state (IGST) tax split, and automatic amount-in-words conversion. All processing happens in your browser — no data is sent to any server.
How this calculator works
A GST tax invoice is a legal document issued by a GST-registered seller to a buyer. Under the GST law, it must contain specific fields — otherwise the buyer cannot claim input tax credit.
Mandatory fields on a GST invoice
- Name, address and GSTIN of the seller
- Invoice number (unique, sequential)
- Invoice date
- Name, address and GSTIN of the buyer (if registered)
- Place of supply (state)
- Description of goods/services with HSN/SAC code
- Quantity, unit price, total value per item
- Taxable value and GST rate applicable per item
- CGST+SGST amounts (intra-state) OR IGST amount (inter-state)
- Total invoice value
- Signature (physical or digital) of the authorised signatory
HSN vs SAC codes
HSN (Harmonised System of Nomenclature) — used for goods, 4-8 digits based on turnover. Under ₹5 crore turnover: 4-digit HSN. Over ₹5 crore: 6-digit mandatory.
SAC (Service Accounting Code) — used for services, always 6 digits. For example, 998313 = Information technology consulting services.
Intra-state vs inter-state
- Intra-state (buyer and seller in same state) → split the GST equally into CGST (Central) + SGST (State). E.g., 18% GST = 9% CGST + 9% SGST.
- Inter-state (different states, or one is a Union Territory) → single IGST at the full rate.
Worked example
Example — Delivering consulting services to a customer in the same state:
- Service: IT consulting (SAC 998313)
- Quantity: 1, Rate: ₹50,000
- Taxable value: ₹50,000
- GST rate: 18% (standard for most services)
- CGST (9%): ₹4,500
- SGST (9%): ₹4,500
- Total invoice: ₹59,000
- Amount in words: "Fifty Nine Thousand Rupees Only"