Quotation vs Proforma Invoice vs Invoice: What's the Difference?

A quotation is a pre-sale price estimate, a proforma invoice is a preliminary bill sent before the deal is finalized, and a tax invoice is the final GST-compliant document that creates a legal payment and tax obligation. Only the tax invoice triggers GST liability — the other two are negotiation and confirmation tools that come before it.

Why these three get confused

All three documents can look nearly identical — same layout, same line items, same totals — which is exactly why they get mixed up. The difference isn't in appearance; it's in what stage of the deal each one represents and what legal or tax effect it has. Sending a proforma invoice when you meant to issue a tax invoice (or vice versa) is a common and avoidable mistake for freelancers and agencies handling their own billing.

What is a quotation?

A quotation is an estimate you send before any commitment exists. It tells a prospective client what a project or product will cost if they go ahead, but it isn't a bill and creates no obligation on either side.

• Sent at the inquiry stage, before work starts
• Prices may be estimates and can change before the deal is confirmed
• Not legally binding — either party can walk away
• No GST is charged, since no taxable supply has happened yet
• Usually has a validity period (e.g. "valid for 15 days") after which prices may be revised

Quotations exist to help a buyer compare options and make a decision — think of it as the opening move in a sale, not part of the transaction itself.

What is a proforma invoice?

A proforma invoice looks much closer to a real invoice — it can carry the same line items, taxes shown for reference, and a similar layout — but it's still not a demand for payment in the legal sense and it does not create a GST liability.

Proforma invoices are typically used to:

• Confirm final terms after a quotation is accepted, before work begins
• Request an advance payment from the client before starting a project
• Support import/export documentation, where customs or banks require a document showing expected value before goods ship
• Give a client's finance or procurement team something to route through internal approval before the real invoice arrives

A proforma invoice can show GST at the applicable rate purely for the buyer's reference — so they know the all-in cost — but that GST is not payable or reportable at this stage, and it does not create input tax credit eligibility for the buyer.

What is a tax invoice?

A tax invoice is the actual GST-compliant legal document, issued once the supply of goods or services is made (or, for services, generally at or before the time payment is due). This is the document that:

• Creates the seller's GST liability for that transaction
• Gives the registered buyer eligibility to claim input tax credit
• Must contain the full set of mandatory fields — GSTIN of both parties, HSN/SAC code, taxable value, and the CGST/SGST or IGST split
• Consumes a number from your sequential, financial-year invoice series

If you haven't built one of these yet, see how to create a GST invoice step-by-step for the full field-by-field process, or GST invoice format explained for exactly how those fields are laid out on the page.

Quotation vs proforma invoice vs invoice — comparison table

The typical sequence in a real deal

Most B2B service deals in India that use all three documents follow the same order:

1. Quotation — you send an estimate; the client compares it against other vendors or negotiates the scope.
2. Proforma invoice — once terms are agreed, you send a proforma invoice confirming the final scope and price, often to request an advance payment before starting work.
3. Tax invoice — once the work is delivered (or the milestone/payment point under the agreed terms is reached), you issue the actual GST tax invoice, which is the only one of the three that creates GST liability and input tax credit eligibility.

Worked example: the same deal through all three stages

A freelance web developer in Ahmedabad is hired by a client also based in Gujarat (intra-state supply) to build a website for ₹40,000.

Stage 1 — Quotation (sent when the client first inquires)

No GST appears as payable — it's just a price estimate, valid for 15 days.

Stage 2 — Proforma invoice (sent once the client agrees, to request a 50% advance)

The client pays the advance against this document, but the developer has not yet recorded any GST liability — no tax invoice has been issued.

Stage 3 — Tax invoice (issued once the website is delivered)

This is the document that creates the ₹7,200 GST liability, gets a sequential invoice number (e.g. INV-2026-045), and is what the client uses if they want to claim input tax credit. The ₹23,600 advance already collected is adjusted against the ₹47,200 total, leaving ₹23,600 due on delivery.

When GST liability actually kicks in

This is the detail that trips people up most: GST liability is tied to the tax invoice and the time of supply — not to any earlier document. A quotation or proforma invoice can show a GST-inclusive figure purely so the buyer knows the full expected cost, but neither document reports tax to the government, and neither creates a paper trail your GST returns need to account for. If you're unsure exactly which fields turn a document into a compliant tax invoice, the GST invoice mandatory fields checklist covers every required and conditional field.

Common mistakes to avoid

• Charging GST on a proforma invoice as if it were payable — it should be shown as a reference figure only, not booked as tax collected.
• Using proforma invoice numbers from your tax invoice series — keep a separate reference numbering for proformas so your sequential tax invoice series stays clean and audit-ready.
• Treating a quotation as confirmation of a deal — until the client accepts it (usually in writing or via a proforma invoice), scope and price can still change.
• Never issuing a real tax invoice after collecting an advance — the advance must eventually be reconciled against a proper tax invoice once the supply is made, not left as a standalone proforma forever.

Making the sequence easier to manage

Chasing three separate documents by hand for every deal — each with slightly different numbers, wording, and formatting — is where mistakes creep in, like accidentally showing GST as payable on a proforma. A Quotation Maker (launching soon) will let you create and send a professional quotation in minutes, then carry the same line items forward into a proforma and finally a tax invoice, keeping the numbers consistent across all three stages instead of retyping them each time.

For freelancers and agencies who send these regularly, see Dharayana plans to keep client details and line items reusable across quotations, proforma invoices, and tax invoices without re-entering them at every stage.

Frequently asked questions

Is a proforma invoice legally binding?

No. A proforma invoice is a preliminary document that states expected terms and pricing — it doesn't create a legal obligation to pay or a GST liability. It becomes binding only once both parties confirm the deal and a tax invoice or contract is issued.

Can I charge GST on a quotation or proforma invoice?

No. GST liability arises only when a tax invoice is issued at the time of supply. Quotations and proforma invoices are pre-sale documents and must not show GST as a payable amount, even if they display the applicable rate for the buyer's reference.

Do I need to issue all three documents for every sale?

No. Many small, straightforward sales skip straight to a tax invoice. Quotations are useful when the buyer is comparing options or negotiating; proforma invoices are useful when an advance payment, import/export declaration, or internal approval is needed before the final invoice.

Can a proforma invoice be used to claim input tax credit?

No. Input tax credit can only be claimed against a valid tax invoice (or a debit note/prescribed document) that carries a GSTIN and follows the mandatory tax invoice fields. A proforma invoice, however detailed, doesn't qualify.

What happens if I send a proforma invoice and the client never confirms the deal?

Nothing — that's the point of a proforma invoice. Since it isn't a binding sale document and no tax invoice was issued, there's no GST liability, no revenue to record, and no invoice number consumed from your sequential series.

Ready to send your next estimate? The Quotation Maker will carry the same details into a proforma and final tax invoice, keeping every stage consistent — free to use, and launching soon.