How to Create a GST Invoice in India

GST Invoice Format in India: Complete Guide for 2024

Under India's Goods and Services Tax framework, invoices are legal documents that trigger tax obligations and Input Tax Credit claims. Getting the format right isn't optional — incorrect GST invoices can be rejected by clients, cause ITC mismatches, and trigger compliance notices. This guide covers every element required in a valid GST invoice and how to structure one correctly.

Who Must Issue GST Invoices?

Every GST-registered supplier of goods or services must issue a GST-compliant tax invoice. This applies to:

• Businesses and professionals with annual turnover above ₹20 lakhs (₹10 lakhs for special category states) who are GST registered
• Voluntarily registered businesses even below the threshold
• Suppliers making inter-state taxable supplies (mandatory registration regardless of turnover for inter-state supplies)

Composition scheme taxpayers (who pay GST at a flat rate on turnover) must issue "Bill of Supply" instead of a tax invoice and cannot charge GST separately on the invoice.

Mandatory Fields on a GST Tax Invoice

Rule 46 of the CGST Rules specifies the mandatory fields for a tax invoice:

1. Name, Address, and GSTIN of the Supplier
Your registered business name exactly as it appears on your GST certificate, registered address, and 15-digit GSTIN.

2. Nature of Tax Invoice
The document must be titled "TAX INVOICE" (not just "Invoice" or "Bill"). This distinction is legally important.

3. Invoice Serial Number
A consecutive serial number containing only alphabets, numerals, or special characters (hyphen, dash, slash). Each financial year begins a new series. Example: INV-2024-25/001, INV-2024-25/002, etc.

4. Date of Issue
The date the invoice is issued. For services, the invoice must be issued within 30 days of the date of supply of service.

5. Name, Address, and GSTIN of the Recipient
For B2B transactions (registered buyer), the recipient's GSTIN must appear. Without the recipient's GSTIN, they cannot claim Input Tax Credit. For B2C transactions (unregistered buyers with invoice value above ₹2.5 lakhs), include their name and address. For B2C transactions below ₹2.5 lakhs, recipient details are optional.

6. HSN/SAC Code
Harmonized System of Nomenclature (HSN) codes for goods; Service Accounting Codes (SAC) for services. Requirements by turnover tier:

• Up to ₹5 crore: 4-digit HSN code
• Above ₹5 crore: 6-digit HSN code

Commonly used SAC codes for professional services: 998313 (IT/software services), 998361 (management consulting), 999299 (other professional services).

7. Description of Goods or Services
Clear description of what was supplied. For services, this should correspond to the SAC code.

8. Quantity
Unit of measure (hours, days, pieces, kg, etc.) and quantity supplied.

9. Total Value of Goods or Services
The aggregate value before tax.

10. Taxable Value and Discounts
If discounts are offered, show them separately. The taxable value is the value on which GST is calculated.

11. Applicable Rate and Amount of GST
Show CGST and SGST separately for intra-state supplies, or IGST for inter-state supplies. Never combine them. Format:

• Intra-state (e.g., Maharashtra to Maharashtra): CGST @ 9% = ₹X, SGST @ 9% = ₹X
• Inter-state (e.g., Maharashtra to Karnataka): IGST @ 18% = ₹X

12. Place of Supply
State name and state code. For intra-state supplies, the place of supply is the destination state. This determines whether CGST+SGST or IGST applies.

13. Whether Tax is Payable on Reverse Charge
If the supply falls under reverse charge mechanism (where the recipient pays GST instead of the supplier), this must be stated.

14. Signature or Digital Signature
Invoice must be signed (physically or digitally) by the supplier or an authorized representative.

Sample GST Invoice Structure

Here's how a complete GST invoice is typically laid out:

TAX INVOICE

[Your Business Name]
[Registered Address]
GSTIN: [Your 15-digit GSTIN]

Invoice No.: INV-2024-25/042         Date: 15 March 2024
Place of Supply: Maharashtra (27)

Bill To:
[Client Name]
[Client Address]
GSTIN: [Client GSTIN]

------------------------------------------------------------------
Sr | Description                    | SAC   | Qty | Rate  | Amount
------------------------------------------------------------------
1  | Website Development Services   | 998313|  1  |₹50,000|₹50,000
------------------------------------------------------------------
                                          Subtotal: ₹50,000
                                          CGST @ 9%:  ₹4,500
                                          SGST @ 9%:  ₹4,500
                                          Total:     ₹59,000
------------------------------------------------------------------

Amount in Words: Fifty-Nine Thousand Rupees Only

Payment Terms: Net 30 days
Bank Details: [Account Name, Bank, Account No., IFSC]

Whether tax is payable under reverse charge: No

Authorized Signatory: [Signature]

Time Limits for Issuing GST Invoices

For services, the invoice must be issued within 30 days of the date of supply. Late invoicing can cause ITC issues for your clients and may attract penalties under GST law.

E-Invoicing Requirements

Businesses with annual aggregate turnover above ₹5 crore must generate e-invoices through the Invoice Registration Portal (IRP). The IRP generates an Invoice Reference Number (IRN) and a QR code that must appear on the physical invoice. Standard invoicing software does not automatically handle e-invoicing — you need integration with an IRP or a GST-compliant accounting platform.

Credit Notes and Debit Notes

When an invoice needs to be modified after issuance (returned goods, overcharged amount, rate revision), issue a credit note (to reduce tax) or debit note (to increase tax). These follow a similar format to tax invoices but are titled "CREDIT NOTE" or "DEBIT NOTE" and reference the original invoice number.

Common Mistakes to Avoid

• Missing recipient GSTIN: Your B2B client can't claim ITC without it — they will refuse the invoice
• Wrong HSN/SAC code: Causes GSTR-2A mismatches and ITC disputes
• CGST+SGST on inter-state supplies: Inter-state must use IGST only — splitting into CGST and SGST is incorrect
• Not mentioning "TAX INVOICE": "Invoice" alone is not a valid tax invoice for GST purposes
• Sequential numbering gaps: Skipping invoice numbers creates audit questions