Proforma Invoice vs Tax Invoice in India: Key Differences

What Is a Proforma Invoice?

A proforma invoice is a preliminary document sent by a seller to a prospective buyer before a sale is confirmed. It describes the goods or services, quantities, prices, and estimated taxes — but it is not a legal demand for payment and does not create a GST liability.

Think of it as a detailed quotation or pre-shipment estimate. Proforma invoices are widely used in:

• Export trade (for customs and import license purposes)
• Government tenders and procurement
• Project proposals and advance quotes
• Advance payment requests before service delivery

What Is a Tax Invoice?

A tax invoice is the official GST document issued by a registered supplier after making a taxable supply. It is a legal record that:

• Creates a GST liability for the supplier
• Allows the buyer to claim Input Tax Credit
• Must be reported in GSTR-1 returns
• Serves as proof of supply in legal disputes

Key Differences Side by Side

• Purpose: Proforma = pre-sale estimate | Tax Invoice = post-supply legal document
• GST liability: Proforma = None | Tax Invoice = Yes, at the rate shown
• ITC eligibility for buyer: Proforma = No | Tax Invoice = Yes
• GSTR-1 reporting: Proforma = Not reported | Tax Invoice = Mandatory
• Sequential numbering: Proforma = Separate series | Tax Invoice = Mandatory consecutive series
• Time of issuance: Proforma = Before supply | Tax Invoice = At or after supply
• Legal enforceability: Proforma = Not binding | Tax Invoice = Legally binding
• Revisions: Proforma = Can be revised freely | Tax Invoice = Cannot be edited; use credit/debit note

When to Use a Proforma Invoice

• Export inquiries — Buyers in foreign countries need a proforma to open a Letter of Credit (LC) with their bank
• Advance payment requests — Ask for a deposit before starting work, without triggering a GST event
• Government quotations — Many government departments require a proforma before issuing a purchase order
• Import customs purposes — Customs authorities may accept a proforma for assessment if the final invoice isn't available
• Large project estimates — When the final scope isn't confirmed, a proforma lets both parties agree on approximate costs

When to Use a Tax Invoice

• When the supply has been delivered or the service has been rendered
• When you receive full or partial payment for a taxable supply
• For all B2B supplies where the buyer will claim ITC
• For export of goods or services (with or without IGST)

Proforma Invoice Format in India

While there is no legal format requirement, a proforma invoice should include:

• The words "PROFORMA INVOICE" prominently displayed
• Your business name, address, and GSTIN (for reference)
• Proforma number (separate series, e.g., PI-2026-001)
• Date of issue and validity period (e.g., "Valid for 30 days")
• Buyer name and address
• Description of goods/services, quantity, unit price
• Estimated GST (clearly marked as "Indicative / Estimated")
• Payment terms and bank details
• Delivery terms (especially for exports: FOB, CIF, etc.)

Proforma to Tax Invoice — The Workflow

1. Send proforma invoice to buyer for approval
2. Buyer reviews, negotiates, and confirms the order
3. You deliver goods or render services
4. Issue a tax invoice with its own sequential number
5. The proforma is archived for reference — it is not reported to GSTN

Never treat a proforma as a tax invoice even if the buyer pays against it. Always follow up with a proper tax invoice after supply.

Common Mistakes

• Using proforma invoice numbers in the tax invoice sequence — These must be entirely separate numbering series
• Treating advance payments as requiring a tax invoice immediately — Under GST, advance received for services triggers a tax liability; you must issue a receipt voucher + tax invoice
• Not marking proforma as "Proforma" — An unlabelled invoice creates confusion with tax invoices during audits
• Reporting proforma invoices in GSTR-1 — Only actual tax invoices belong in GSTR-1