GST & Tax

GST Invoice Format: Rules, Mandatory Fields & Free Template (2026)

Complete guide to Indian GST invoice format rules under Section 31 of CGST Act. Learn mandatory 16 fields, GST 2.0 slabs, time limits & free template.

Last updated: 2026-08-06
By the QuickDocIndia Editorial Team

Issuing a legally compliant gst invoice format is mandatory for every GST-registered business in India. Under the Goods and Services Tax (GST) law, a tax invoice is not just a billing slip—it is the foundational legal proof required by buyer organizations to claim Input Tax Credit (ITC) under Section 16 of the CGST Act 2017.

Whether you need a simple gst invoice format for small business billing, a non gst invoice format for exempted supplies, or editable templates in gst invoice format in excel, gst invoice format in word, or gst invoice format pdf, this guide covers statutory rules, mandatory fields, tax slab splits, and time limits.


1. What is a GST Invoice and Statutory Rules in India

An indian gst invoice format is an official commercial bill issued by a registered supplier when selling taxable goods or services.

Under Section 31 of the Central Goods and Services Tax (CGST) Act, 2017, issuing a tax invoice is mandatory whenever a registered taxpayer makes a taxable supply exceeding ₹200, or whenever a registered recipient requests an invoice regardless of transaction value.

Before final billing, businesses often issue a preliminary Proforma Invoice to outline terms before goods dispatch.


2. Who Must Register and Issue GST Invoices?

Under Section 22 and 24 of the CGST Act 2017, businesses must register for GST and issue valid GST invoices once aggregate annual turnover exceeds statutory thresholds:

  • Supply of Goods: Aggregate annual turnover exceeding ₹40 Lakhs (₹20 Lakhs for Special Category / North-Eastern States).
  • Supply of Services: Aggregate annual turnover exceeding ₹20 Lakhs (₹10 Lakhs for Special Category States).
  • Mandatory E-Commerce & Inter-State Sellers: Inter-state taxable suppliers and e-commerce vendors must register for GST regardless of turnover volume.

3. The 5 Key GST Billing Documents Explained

GST regulations prescribe 5 distinct commercial documents tailored to specific transaction flows:

Document Type Scenario / Issuing Entity ITC Claim Eligibility
Tax Invoice Registered taxpayer making taxable supplies (gst invoice format) Eligible for ITC
Bill of Supply Composition Scheme dealers or exempt goods suppliers (non gst invoice format) ❌ No ITC Allowed
Credit Note Issued by seller to decrease tax liability (sales return, discount) Reduces Tax Payable
Debit Note Issued by seller to increase tax liability (price revision, shortage) Increases Tax Payable
Delivery Challan Transportation of goods without immediate sale (job work, branch transfer) Non-Taxable Instrument

4. 16 Mandatory Fields Required on a Valid GST Tax Invoice

Under Rule 46 of the CGST Rules, 2017, every valid gst invoice format pdf or paper invoice must contain the following 16 mandatory particulars:

  1. Supplier Details: Legal name, business address, and 15-digit GSTIN (GST Identification Number).
  2. Sequential Invoice Number: A unique consecutive serial number (maximum 16 characters) containing letters, numbers, or slashes, unique for a financial year.
  3. Invoice Date: The exact date of invoice issue.
  4. Recipient Details: Name, address, and GSTIN (for registered B2B buyers) or delivery address (for unregistered B2C buyers).
  5. Place of Supply: Destination State name and State Code (e.g., 27 for Maharashtra, 07 for Delhi, 29 for Karnataka).
  6. HSN / SAC Code: Harmonized System of Nomenclature (for goods) or Service Accounting Code (for services).
  7. Description of Goods/Services: Detailed description of items supplied.
  8. Quantity & UQC: Quantity and Unit Quantity Code (e.g., KGS, NOS, MTR).
  9. Total Valuation: Total taxable value after trade discounts.
  10. Tax Rate Breakdown: Applicable GST percentage and explicit breakdown into CGST + SGST (intra-state) or IGST (inter-state).
  11. Reverse Charge Mechanism (RCM): Indication whether tax is payable under reverse charge (Yes / No).
  12. Signature: Physical signature or digital signature certificate (DSC) of the authorized signatory.

5. CGST + SGST vs IGST: Place of Supply Tax Split Rules

The statutory tax split depends strictly on the Place of Supply relative to the supplier’s location:

Intra-State Supply (Supplier Location = Place of Supply)

When seller and buyer operate in the same state (e.g. Mumbai to Pune):

  • Tax is split equally into CGST (Central GST) and SGST/UTGST (State GST).
  • Example: On an 18% slab item, charge 9% CGST and 9% SGST.

Inter-State Supply (Supplier Location ≠ Place of Supply)

When seller and buyer operate in different states (e.g. Delhi to Bengaluru):

  • Tax is levied entirely as IGST (Integrated GST).
  • Example: On an 18% slab item, charge 18% IGST directly.

Compute exact tax splits using our free GST Calculator or calculate base costs from gross amounts with our Reverse GST Calculator.


6. GST 2.0 Rate Slabs & HSN / SAC Classifications

Following GST Council recommendations effective September 2025 (GST 2.0), India restructured GST into 4 primary rate slabs:

GST Slab Category Product / Service Examples
0% (Exempt) Basic staples, unprocessed food, health & life insurance Unbranded foodgrains, fresh vegetables, books, milk
5% Everyday essential goods & basic medicines Packaged tea, footwear, apparel, essential medicines
18% Standard rate for services, IT, electronics & goods Software consulting, commercial machinery, electronics
40% Sin, luxury & demerit goods Tobacco, luxury cars, aerated beverages, casinos

Verify exact HSN/SAC rate codes on the official CBIC portal (cbic-gst.gov.in).


7. Time Limits for Issuing Invoices & E-Invoicing Mandate

Statutory Invoicing Time Limits

  • Supply of Goods: Invoice must be issued on or before the date of removal or dispatch of goods.
  • Supply of Services: Invoice must be issued within 30 days from service completion (extended to 45 days for Banks, NBFCs, and Insurance Companies).

E-Invoicing Rules

E-Invoicing involves transmitting invoice data from accounting tools to the Government’s Invoice Registration Portal (IRP) to receive a unique 64-character Invoice Reference Number (IRN) and signed QR Code.

E-Invoicing is mandatory for all registered businesses with an aggregate annual turnover exceeding ₹5 Crore in any preceding financial year from 2017-18 onwards.


8. Input Tax Credit (ITC) Rules & 180-Day Payment Condition

To claim Input Tax Credit (ITC) under Section 16 of the CGST Act:

  1. The buyer must hold a valid gst invoice format pdf or paper tax invoice.
  2. The supplier must upload invoice details in GSTR-1, reflecting in the buyer’s GSTR-2B.
  3. 180-Day Rule: Under Section 16(2) of the CGST Act, if the buyer fails to pay the supplier within 180 days from the invoice date, claimed ITC must be reversed along with 18% annual interest.

Calculate overdue interest penalties using our Invoice Late Fee Calculator.


9. How to Create a Free GST Invoice on QuickDocIndia

Generating a GST-compliant tax invoice takes less than 2 minutes:

  1. Open our online GST Invoice Document Builder or view our GST Tax Invoice Format.
  2. Enter your business details, 15-digit GSTIN, and customer billing address.
  3. Select HSN/SAC codes and select the GST 2.0 rate slab (0%, 5%, 18%, 40%).
  4. Add line items, quantities, and rates to auto-compute CGST, SGST, or IGST splits.
  5. Download your instant gst invoice format pdf, or copy text for gst invoice format in excel or gst invoice format in word customization.

Explore related business tools including the GST Calculator, Reverse GST Calculator, and Invoice Late Fee Calculator.

QuickDocIndia Free Tools

Generate Free GST Tax Invoices Online

Create GST 2.0 compliant tax invoices with automatic CGST/SGST/IGST splits, HSN codes, and instant PDF download.

Frequently Asked Questions

Q:What is a GST invoice format under Indian GST law?
A GST invoice format is a mandatory commercial billing document issued by a registered taxpayer in India under Section 31 of the CGST Act 2017. It details goods or services provided, transaction values, HSN/SAC codes, place of supply, and itemized CGST/SGST or IGST tax breakdowns required for claiming Input Tax Credit (ITC).
Q:What is the difference between a tax invoice and a non GST invoice format / bill of supply?
A Tax Invoice is issued by regular GST-registered businesses for taxable goods or services and includes explicit GST charges eligible for Input Tax Credit. A Bill of Supply or non GST invoice format is issued for tax-exempt supplies, non-GST goods, or by Composition Scheme dealers, containing no GST charges and offering no ITC eligibility.
Q:What is the maximum character limit for a GST sequential invoice number?
Under Rule 46(b) of CGST Rules 2017, a GST invoice number must be a consecutive serial number not exceeding 16 characters, containing alphabets, numerals, or special characters (hyphens or slashes), unique for a given financial year.
Q:What is the time limit for issuing a GST invoice for services vs goods?
For goods, the invoice must be issued on or before the date of removal or dispatch. For services, the invoice must be issued within 30 days from the date of service completion (extended to 45 days for Banks, Insurance companies, and financial institutions).
Q:When is e-invoicing mandatory for Indian businesses?
E-Invoicing on the Government's Invoice Registration Portal (IRP) is mandatory for registered businesses with an aggregate annual turnover exceeding ₹5 Crore in any preceding financial year from 2017-18 onwards.
Q:What is the penalty for failing to issue a valid GST tax invoice?
Under Section 122 of the CGST Act 2017, issuing a incorrect invoice or failing to issue a tax invoice for taxable supplies attracts a monetary penalty equal to 100% of the tax amount evaded or ₹10,000, whichever is higher.
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