Proforma Invoice vs Tax Invoice: When to Use Which (India)

A proforma invoice is not a tax invoice. They look identical — same line items, same totals — but they have completely different legal weight under Indian GST. Sending a proforma when you should have sent a tax invoice can cost you the input tax credit on your client's books and a scrutiny note on yours. Here's how to tell them apart.

The 30-second answer

| | Proforma Invoice | Tax Invoice | |---|---|---| | What is it? | A quotation / pre-bill | A formal demand for payment | | Legal status under GST | None | Mandatory document under Rule 46 | | GST liability triggered? | No | Yes — supplier owes GST on issuance | | Client's ITC eligible? | No | Yes | | Numbering required? | No (best practice: separate series) | Yes — unique sequential per FY | | Shown in GSTR-1? | No | Yes | | When is it issued? | Before service / before payment | At or after supply of service |

The single biggest distinction: a tax invoice creates a GST liability the moment it's issued. A proforma doesn't.

What is a proforma invoice?

A proforma is a non-binding estimate sent before work begins or before payment is collected. Common uses:

1. Quoting a project: "Here's what this engagement will cost — please confirm so I can start."
2. Advance payment requests: "Please remit 50% advance against this proforma; final tax invoice on completion."
3. Customs / import documentation: foreign buyer needs an estimate to clear funds internally.
4. Internal approval: enterprise clients run proformas through their AP system before raising a PO.

Crucially, the proforma doesn't trigger GST. You don't collect GST on it, you don't report it in GSTR-1, your client can't claim ITC against it.

What is a tax invoice?

Per Section 31 + Rule 46 of the CGST Act, a tax invoice is a legal document containing 16 specific fields, issued at or after the time of supply.

For services, the time of supply is generally:

• The earlier of: invoice issue date, OR payment receipt date — if the invoice is issued within 30 days of supply.
• The completion-of-service date if the invoice is delayed beyond 30 days.

Once issued, the tax invoice creates an immediate GST liability for the supplier. You must report it in your next GSTR-1 and pay the tax via GSTR-3B by the 20th of the following month — regardless of whether the client has paid you yet.

This last point catches many freelancers. You owe GST on issued invoices, not on collected payments.

When to use which: real-world scenarios

Scenario 1: Client wants a quote before signing

Send a proforma. No GST liability. They can take their time deciding. When they accept, you start work, and at completion you issue the tax invoice.

Scenario 2: Client wants to pay 50% advance

Two clean ways to structure this:

Option A — Proforma + Receipt Voucher

1. Issue proforma for the full ₹1,00,000 + GST.
2. Client pays 50% advance.
3. You issue a Receipt Voucher (per Rule 50 of CGST Rules) acknowledging the advance and including GST on it.
4. On completion, you issue a final tax invoice for the full amount, adjusted for the advance receipt voucher.

Option B — Two tax invoices

1. On signing, issue tax invoice 1 for ₹50,000 + GST = "Advance".
2. Client pays.
3. On completion, issue tax invoice 2 for the remaining ₹50,000 + GST.

Option B is simpler operationally for most freelancers — but you owe GST on the first invoice as soon as it's issued, even if the advance is delayed.

Scenario 3: Client is in another country and needs an estimate for currency conversion

Send a proforma in their currency. Once funds are wired and confirmed by FIRA, issue the tax invoice (zero-rated under LUT). See foreign client invoicing.

Scenario 4: You're already on a long-term retainer

Skip the proforma — issue a tax invoice every cycle. The retainer agreement is the contract; the invoice is the demand for that cycle.

Format of a clean proforma invoice

Same as a tax invoice, with three differences:

1. Document title says "PROFORMA INVOICE" at the top — clearly, in big letters.
2. Numbering uses a separate series, e.g. PRO/25-26/0001, distinct from your tax invoice series (INV/25-26/0001).
3. Optional but recommended: a footer note — "This is not a tax invoice. A tax invoice will be issued upon acceptance / completion of services."

Everything else — your name, GSTIN, client details, line items, GST split, place of supply — stays the same. The mental model: a proforma is a draft of the tax invoice you'll eventually issue.

Common mistakes

1. Sending a proforma and then forgetting to issue the tax invoice

Happens constantly. Client pays against the proforma, treats it as a paid invoice, and 6 months later the missing tax invoice surfaces in their GST audit. You're scrambling to issue it backdated.

The fix: as soon as a proforma converts (i.e., the client accepts and starts paying), put a calendar reminder to issue the tax invoice. Or use a tool that converts proforma to tax invoice in one click.

2. Numbering both in the same series

If you use INV/0001 for proforma and INV/0002 for the tax invoice, your serial numbering is broken. Use separate prefixes — PRO/... for proforma, INV/... for tax invoices. See our invoice numbering guide.

3. Charging GST on the proforma

You're not supposed to. GST is only collected on tax invoices (or receipt vouchers for advances). Showing GST on a proforma is fine for clarity — but you're not actually collecting it yet.

4. Treating proforma as a binding contract

Legally, it isn't. If the client accepts a proforma and then disputes the price, the proforma alone doesn't bind them. Always pair it with a written engagement letter / signed quote / email confirmation.

Estimate vs proforma vs tax invoice — the full hierarchy

| Document | Binding? | Triggers GST? | Required fields | |---|---|---|---| | Estimate / Quote | No (informal) | No | Free-form | | Proforma Invoice | No (signal of intent) | No | Most fields of a tax invoice, sans legal weight | | Tax Invoice | Yes (legal demand) | Yes | All 16 mandatory fields | | Receipt Voucher | Yes (against advance) | Yes (on advance amount) | Specific Rule 50 fields | | Bill of Supply | Yes (legal demand, no GST) | No (issued by non-GST suppliers) | Similar fields, no GST line |

If you're a registered freelancer, you'll mostly cycle between proforma → tax invoice for project work, and straight tax invoice for retainers.

Frequently asked questions

Can a proforma have a GST line? You can show estimated GST for transparency, but you're not collecting it. The actual GST collection happens on the tax invoice.

Is the proforma number reportable in GSTR-1? No — only tax invoices, debit/credit notes, and receipt vouchers go in GSTR-1.

What if my client treats my proforma as a tax invoice and claims ITC? They can't legally — ITC requires a valid tax invoice. If they tried, their ITC claim would be denied on audit. You should issue the actual tax invoice as soon as services begin.

Do I need to share the proforma with the GST department? No. Proformas have no statutory reporting requirement.

Can I convert a proforma to a tax invoice? Yes. Issue the tax invoice with a fresh INV/... number and note "Reference: Proforma PRO/25-26/000X" on the new invoice. Don't reuse the proforma's number.

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invoicely lets you issue a proforma in one click and convert it to a tax invoice when accepted — same client, same line items, separate numbering series. Free for your first 3 invoices/month.