Tax Invoice explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.
Section 31 — Tax Invoice (The Most Important Document in GST)
Every registered person supplying taxable goods or services MUST issue a tax invoice. Without a valid tax invoice, your buyer CANNOT claim ITC. The invoice is the single document that creates the entire credit chain in GST.
Mandatory Contents of Tax Invoice (Rule 46)
| Field | Requirement |
|---|---|
| Supplier details | Name, address, GSTIN of supplier |
| Invoice number | Sequential, maximum 16 characters, unique per financial year |
| Date of issue | Date of invoice (determines time of supply) |
| Recipient details | Name, address, GSTIN (if registered), state code |
| HSN/SAC code | 4-digit if turnover Rs. 5 Cr+, 6-digit if Rs. 5 Cr+ |
| Description | Description of goods/services |
| Quantity and unit | For goods (not required for services) |
| Taxable value | Value before GST |
| Tax rate and amount | CGST, SGST, or IGST — rate and amount separately |
| Place of supply | State name and code (for inter-state: mandatory) |
| Signature | Digital signature or manual (physical invoice) |
Invoice Timing
For goods: before or at the time of removal (if involves movement) or delivery (no movement). Continuous supply of goods: before or at the time of each statement of account or payment.
For services: within 30 days from the date of supply (45 days for banking/insurance/financial). If invoice not issued in time: time of supply becomes the date of supply (not invoice date) — resulting in delayed payment = interest.
Section 34 — Credit Note and Debit Note
Credit Note: issued when taxable value or tax charged in the original invoice is found to EXCEED the actual value/tax. Reasons: goods returned, post-supply discount, rate difference, excess billing. Effect: reduces the supplier's output tax liability. Time limit: September 30 following the end of the FY of the original invoice, or the date of annual return, whichever is earlier.
Debit Note: issued when taxable value or tax charged is found to be LESS than actual. Reasons: price escalation, additional charges, short billing. Effect: increases supplier's output tax liability.
Recipient impact: when supplier issues credit note, recipient must REDUCE ITC by the corresponding amount. When supplier issues debit note, recipient can INCREASE ITC.
E-Invoice (Electronic Invoice) — Rule 48(4)
E-invoicing is mandatory for B2B and export invoices for businesses with aggregate turnover exceeding specified threshold:
| From Date | Turnover Threshold |
|---|---|
| October 1, 2020 | Rs. 500 crore+ |
| January 1, 2021 | Rs. 100 crore+ |
| April 1, 2021 | Rs. 50 crore+ |
| April 1, 2022 | Rs. 20 crore+ |
| October 1, 2022 | Rs. 10 crore+ |
| August 1, 2023 | Rs. 5 crore+ |
Process: Generate invoice in your accounting software → upload JSON to Invoice Registration Portal (IRP: einvoice1.gst.gov.in) → IRP validates, generates IRN (Invoice Reference Number) and QR code → invoice is valid only with IRN. Without IRN, the invoice is deemed invalid — buyer cannot claim ITC.
Auto-population: E-invoiced data auto-populates GSTR-1 (no manual entry needed for e-invoiced transactions). This reduces filing errors and reconciliation issues.
Bill of Supply — When No Tax Invoice is Needed
A Bill of Supply (not tax invoice) is issued for: (a) exempt supplies, (b) supplies by composition dealers, (c) supplies where GST is paid by recipient under RCM (some categories). Bill of supply does NOT contain tax amount — and the buyer gets NO ITC.
Key Facts About Tax Invoice
- Applies in: All states across India, under the relevant central law.
- Mode: Mostly online via the official government portal.
- Typical timeline: Ranges from a few days to a few weeks depending on the case.
- Non-compliance: May attract penalties, interest or late fees.
- Expert help: TaxClue completes the entire process end to end for you.
What is the difference between tax invoice and bill of supply?
Tax invoice is issued for TAXABLE supplies — it contains GSTIN, HSN/SAC, tax rate, and tax amount. The buyer can claim ITC using a tax invoice. Bill of supply is issued for EXEMPT supplies or by composition dealers — it does NOT contain tax amount and the buyer CANNOT claim ITC. Using the wrong document type is a compliance violation and can result in ITC denial for the buyer and penalty for the supplier.
What is e-invoice and who must generate it?
E-invoice is the electronic generation of invoices through the Invoice Registration Portal (IRP). Mandatory for businesses with aggregate turnover exceeding Rs. 5 crore (as of August 2023, threshold being progressively reduced). The supplier uploads invoice data in JSON format to the IRP, which validates it, assigns an IRN (Invoice Reference Number), signs it digitally, and returns a QR code. Without IRN, the invoice is deemed invalid — the buyer cannot claim ITC on it. E-invoiced data auto-populates GSTR-1.
Over 90% of compliance penalties in India arise from missed due dates — timely handling can save businesses thousands of rupees each year.
Tax Invoice: a key compliance topic in Indian tax and corporate law that businesses and individuals must understand to remain compliant.