A GST (Goods and Services Tax) invoice is a legal document issued by a registered supplier to a buyer for taxable goods or services. Its format is not discretionary: the GST law prescribes every field that must appear on a compliant invoice and an invoice that omits any of them can disqualify the buyer from claiming input tax credit (ITC). For businesses, that is a direct cost.
The Central Goods and Services Tax (CGST) Rules, 2017, specifically Rule 46, list what a tax invoice must contain. The rules apply to all GST-registered businesses, whether they supply goods, services or both. Understanding the required format before designing your GST bill book prevents compliance gaps and rejected ITC claims downstream.
What are the mandatory fields in a GST invoice format
Rule 46 of the CGST Rules, 2017, specifies 17 mandatory fields that every tax invoice must contain. Each field has a specific purpose in the GST compliance chain.
|
Field |
What it must show |
Why it matters |
|
Name, address and GSTIN of the supplier |
Legal name as on GST registration, full address and 15-digit GSTIN |
Identifies the registered supplier issuing the invoice |
|
Tax invoice number |
A consecutive serial number, unique for the financial year (FY), up to 16 characters |
Required for filing GSTR-1 and for ITC matching |
|
Date of issue |
The date the invoice is created (DD/MM/YYYY format recommended) |
Determines the tax period for return filing |
|
Name, address and GSTIN of the recipient |
GSTIN mandatory for registered recipients; name and address for unregistered buyers |
Enables the buyer to claim ITC |
|
Place of supply |
State code of the place where the supply occurs |
Determines whether CGST+State GST (SGST) or Integrated GST (IGST) applies |
|
HSN or SAC code |
Harmonised System of Nomenclature (HSN) for goods or Services Accounting Code (SAC) for services |
Classifies the supply for tax rate determination |
|
Description of goods or services |
Clear description of what is being supplied |
Helps auditors and buyers verify the supply |
|
Quantity and unit |
Number of units and unit of measurement (e.g., kg, nos., litres). Applies to goods; not mandatory for services |
This helps accurately determine the taxable value, verify HSN classification and prevent mismatches during GST audits or return reconciliation. |
|
Total value of the goods or services |
Gross value of the sale |
Helps estimate the correct taxable amount. |
|
Total taxable value |
Value of supply after discounts, before tax |
The basis on which GST is calculated |
|
Applicable tax rate |
Rate of CGST, SGST/UTGST or IGST applicable to the supply |
Must match the GST rate for the HSN/SAC code |
|
Amount of tax |
Tax calculated separately for CGST, SGST/UTGST and IGST |
Buyer uses this for ITC; supplier records tax liability |
|
Place of origin (for interstate) |
State of origin if IGST applies |
Required for cross-state supplies |
|
Signature or digital signature |
Authorised signatory’s signature or DSC |
Authenticates the invoice |
|
Reverse charge applicability |
State ‘Yes’ if tax is payable by recipient under reverse charge mechanism (RCM) |
Mandatory declaration under GST law |
|
Discount (if any) |
Pre-supply discount deducted before tax calculation |
Only pre-supply discounts reduce taxable value; post-supply discounts require a credit note |
|
Shipping address (if different) |
Delivery address if it differs from the billing address |
Required when goods are dispatched to a different location |
GST invoice for exports
Export invoices must carry the declaration “SUPPLY MEANT FOR EXPORT ON PAYMENT OF IGST” or “SUPPLY MEANT FOR EXPORT UNDER BOND OR LETTER OF UNDERTAKING WITHOUT PAYMENT OF IGST”. They must also include the buyer’s country and, where applicable, the shipping bill or bill of export number.
GST invoice template: a practical example
Below is a simplified GST invoice bill format based on the mandatory fields under Rule 46. This example covers a business-to-business (B2B) supply of goods within the same state (intrastate), where CGST and SGST apply.
|
Invoice field |
Example value |
|
Supplier name |
Sunrise Trading Co. |
|
Supplier address |
12, MG Road, Bengaluru, Karnataka – 560001 |
|
Supplier GSTIN |
29AABCS1429B1Z1 |
|
Invoice number |
STC/2024-25/0042 |
|
Invoice date |
15/07/2024 |
|
Buyer name |
Horizon Retail Pvt. Ltd. |
|
Buyer address |
8, Commercial Street, Bengaluru, Karnataka – 560001 |
|
Buyer GSTIN |
29AACCH4523M1Z3 |
|
Place of supply |
Karnataka (State code: 29) |
|
HSN code |
6205 (Men’s shirts) |
|
Description |
Men’s cotton shirts, white, size M |
|
Quantity |
200 nos |
|
Rate per unit |
₹500 |
|
Taxable value |
₹1,00,000 |
|
CGST @ 6% |
₹6,000 |
|
SGST @ 6% |
₹6,000 |
|
Total invoice value |
₹1,12,000 |
|
Reverse charge applicable |
No |
|
Authorised signatory |
Ramesh Kumar (Director) |
For an interstate supply, IGST would apply instead of CGST+SGST, at 12% on the taxable value (i.e., ₹12,000 IGST, total ₹1,12,000 – same total, different tax component).
ConclusioA GST invoice must include specific mandatory fields under the GST Act, from GSTIN and HSN codes to tax breakdowns. Missing even one field can make an invoice non-compliant and block your buyer’s input tax credit claim.
Getting your GST invoice format right is not a one-time task; it is an ongoing compliance requirement. Every invoice you issue affects your buyer’s ITC eligibility, your own GSTR-1 accuracy and your audit trail. The mandatory fields under Rule 46 are non-negotiable and even a single missing field can make an invoice legally deficient.
If you want to eliminate manual errors and generate GST-compliant invoices consistently, TallyPrime’s built-in invoicing module handles the mandatory fields, tax calculations, HSN code mapping and serial number management automatically.
