GST Invoice Format India 2026 —
Mandatory Fields, Rules & Free Template
A GST invoice that's missing even one mandatory field is not legally compliant — and your buyer cannot claim Input Tax Credit on it. This guide covers every required field, the B2B vs B2C differences, common mistakes to avoid, and a free tool to generate compliant invoices without manually checking every rule.
Key Rule
The GST Act (Section 31) mandates specific content on every tax invoice but does NOT prescribe a fixed template. Your invoice can be any format or design — as long as all mandatory fields are present and correctly filled.
Complete GST Invoice Format — Section by Section
Supplier Details (Top of Invoice)
- Legal name of business (as registered under GST)
- Registered address
- GSTIN (15-digit GST Identification Number)
- State and state code
- Contact number and email (recommended)
Invoice Header
- Words 'TAX INVOICE' clearly printed (mandatory wording)
- Invoice number — unique, sequential, not repeating in a financial year
- Invoice date
- Financial year reference (optional but helpful)
Buyer Details
- Name and address of buyer
- GSTIN of buyer (mandatory for B2B invoices)
- Place of supply — the state where goods/services are delivered
- Delivery address if different from billing address
Line Items
- Description of goods or services
- HSN code (for goods) or SAC code (for services)
- Quantity and unit of measure
- Unit price (excluding GST)
- Discount (if any)
- Taxable value per line item
Tax Calculation
- GST rate applicable
- CGST amount (for intra-state supplies)
- SGST / UTGST amount (for intra-state supplies)
- IGST amount (for inter-state supplies)
- Total tax amount
- Total invoice value (taxable + tax)
- Amount in words
Payment & Signature
- Bank account details (name, bank, IFSC, account number) for NEFT/RTGS
- UPI ID (optional but useful)
- Payment terms and due date
- Signature or digital signature of authorised person
- Declaration: 'We declare that this invoice shows the actual price of the goods/services described and that all particulars are true and correct.'
B2B vs B2C Invoice — Key Differences
| Rule | B2B Invoice (buyer is GST-registered) | B2C Invoice (buyer is unregistered) |
|---|---|---|
| Buyer GSTIN | Mandatory | Not applicable |
| Invoice must be uploaded to GST portal | Yes — appears in GSTR-1 | Only if value > ₹2.5 lakh (inter-state) |
| Buyer can claim ITC | Yes | No |
| Document type | Tax Invoice | Tax Invoice (B2C) or Bill of Supply for exempt |
| E-invoice requirement | Mandatory if turnover > ₹5 crore | Not required |
Most Common GST Invoice Mistakes in India
- ✗ Showing total GST instead of splitting CGST and SGST
Fix: Always show CGST and SGST separately for intra-state; IGST for inter-state - ✗ Wrong place of supply
Fix: Place of supply = delivery state, not supplier's state. Determines CGST/SGST vs IGST - ✗ Missing HSN/SAC code
Fix: Look up your goods/services on the GST HSN code finder. All B2B invoices must include it - ✗ Duplicate invoice numbers
Fix: Invoice numbering must be sequential and unique within a financial year - ✗ Using company trade name instead of registered legal name
Fix: The name on the invoice must match your GST registration exactly
Skip the Manual Format — Generate Compliant Invoices Free
Balaji Invoice automatically handles CGST/SGST vs IGST, sequential invoice numbering, and all mandatory fields. You just enter your business details once and fill in line items — the correct format is handled for you.
Frequently Asked Questions
Can I use any format for a GST invoice or is there a prescribed format?
The GST Act does not prescribe a fixed template or layout, but it mandates specific fields that every GST invoice must contain. As long as all mandatory fields are present, you can design the invoice in any layout — printed, digital PDF, or generated by invoicing software. The content is what matters, not the visual design.
What is the time limit to issue a GST invoice in India?
For goods: invoice must be issued at or before delivery (or removal) of goods. For services: invoice must be issued within 30 days of the date of supply of service (45 days for banks and financial institutions). Issuing invoices late can result in mismatch in GSTR-1 and GSTR-2B, which delays ITC claims for your buyers.
What is a Bill of Supply and when do I issue it instead of a GST invoice?
A Bill of Supply is issued by GST-registered suppliers when: (1) supplying exempt goods or services, (2) they are under the Composition Scheme, or (3) exporting goods/services. A Bill of Supply does not show any GST amount. It is a simpler document than a tax invoice and does not allow the buyer to claim ITC.
