GST Invoice

A GST Invoice is the official billing document issued by a GST-registered supplier when supplying taxable goods or services in India. It serves as the legal record of the transaction, the basis for the supplier's GST liability, and the document that entitles the recipient to claim Input Tax Credit (ITC). The terms "GST Invoice" and "Tax Invoice" are used interchangeably in practice — both refer to the same document under the CGST Act.

GST invoices are mandatory for all B2B transactions and for B2C transactions above ₹2.5 lakh (inter-state).

Types of GST Invoices

Depending on the nature of the supply and the registration status of the supplier, different invoice documents are used:

A Tax Invoice is the standard GST invoice issued for taxable supplies. It includes a full GST breakup and enables ITC for the recipient. This is the most common form.

A Bill of Supply is issued when the supplier is under the Composition Scheme or the supply is exempt. No GST is charged and ITC cannot be claimed by the recipient.

A Proforma Invoice is a pre-supply document sent before the actual supply takes place. It is not a GST invoice in the legal sense and does not create a tax liability.

A Receipt Voucher is issued when an advance payment is received before the supply. It acknowledges the advance and triggers GST liability on the amount received.

A Export Invoice is issued for supplies to overseas recipients. It is zero-rated and issued either under LUT (no IGST) or with IGST charged and later refunded.

Mandatory Fields on a GST Invoice

As per Rule 46 of the CGST Rules, 2017, every GST invoice must contain:

Name, address, and GSTIN of the supplier
Consecutive serial number, unique within a financial year
Date of issue
Name, address, and GSTIN of the recipient (mandatory for B2B)
HSN code for goods or SAC code for services
Description, quantity, and unit of goods or nature of services
Total taxable value after discounts
Applicable GST rate and tax amount (CGST + SGST for intra-state, IGST for inter-state or exports)
Place of supply with state name and code
Whether tax is payable under Reverse Charge Mechanism
Signature or digital signature of the supplier

GST Invoice for Intra-State vs. Inter-State Supplies

The tax components shown on a GST invoice depend on the place of supply:

When the supplier and recipient are in the same state, the invoice shows CGST + SGST at equal rates.

When the supplier and recipient are in different states, or the supply is an export, the invoice shows IGST at the combined rate.

For example, an 18% GST transaction appears as 9% CGST + 9% SGST on an intra-state invoice, and as 18% IGST on an inter-state invoice.

GST Invoice Numbering

Every GST invoice must carry a unique, sequential serial number within the financial year. A common format used by Indian businesses is INV/2026/001 or similar. The numbering must restart at the beginning of each financial year (1st April) and cannot repeat within the same year.

Time Limit for Issuing a GST Invoice

For goods, the invoice must be issued at or before the time of removal or delivery. For services, it must be issued within 30 days of the date of supply. For banking and insurance services, this limit is 45 days.

E-Invoicing

Businesses with annual turnover above ₹5 crore are required to generate e-invoices — where every B2B GST invoice is registered on the Invoice Registration Portal (IRP) and assigned a unique IRN (Invoice Reference Number) and digitally signed QR code before it is issued. E-invoicing enables real-time reporting and eliminates manual data entry in GSTR-1.

Businesses below the ₹5 crore threshold — which includes most freelancers, small businesses, and startups — are not required to generate e-invoices and can use tools like JetInvoice to create compliant GST invoices directly.

GST Invoice and ITC

A valid GST invoice is the primary document that entitles the recipient to claim ITC. The invoice must appear in the recipient's GSTR-2B (auto-populated from the supplier's GSTR-1) for the ITC claim to be valid. Any missing or mismatched invoice in GSTR-2B can result in ITC being disallowed.

Amendments to a GST Invoice

If an error is found in an issued GST invoice, it cannot be deleted. Instead:

A Credit Note is issued to reduce the invoice value (e.g., returns or discounts).

A Debit Note is issued to increase the invoice value (e.g., additional charges).

Both must be reported in GSTR-1 and are reflected in the recipient's GSTR-2B.

Create professional, fully GST-compliant invoices in under 2 minutes with JetInvoice's free GST Invoice Generator — auto CGST/SGST/IGST calculation, HSN/SAC code search, GSTIN lookup, and WhatsApp sharing built in.