What Is Quotation to Invoice?
Every deal starts as a price on paper and ends as a document the tax department will recognise.
Quotation to invoice is the step where an accepted quotation becomes a GST tax invoice under India’s CGST Act, carrying the same items, quantities and rates across while adding the fields that give the document legal weight. A quotation is only an offer and creates no tax liability. The invoice is the record both parties file against.
Retyping is what breaks the chain. Across the retail counters we work with, the bill that goes wrong is usually the one somebody typed fresh instead of the agreed rates, which is why so many Indian SMEs are digitising invoice handling.
What Changes Between the Quote and the Invoice
Six fields do most of the work, and two never appeared on the quotation at all.
| Field | On the quotation | On the tax invoice |
|---|---|---|
| Number | Quote series such as QT-2026/207 | Fresh serial from your invoice series |
| GSTIN | Usually the seller’s only | Both, if the buyer is registered |
| HSN | Often left out | Required, by turnover slab |
| Place | Not needed | Decides IGST or CGST plus SGST |
| Tax | Shown so the buyer can budget | Charged, collected and filed |
| Validity | An expiry date | Replaced by a payment due date |
Three of those go missing more than the rest:
- The buyer’s GSTIN, without which their input tax credit is gone
- The place of supply, which sets whether tax splits in two or goes out as IGST
- A new invoice number, because reusing the quote number breaks your serial
Rates should come off a price list, not anybody’s memory. And once the buyer accepts, most trades pass through a purchase order before the tax invoice goes out.
Quotation vs Tax Invoice
Buyers mix these two up far more often than sellers, and it surfaces at credit-claim time.
| Aspect | Quotation | Tax invoice |
|---|---|---|
| Job | Win the order | Record the supply |
| Tax due | None | Payable that period |
| Buyer ITC | Not allowed | Allowed on this document |
| In books | No entry | Sales entry, then GSTR-1 |
| Ends when | Validity lapses | Payment clears |
Quotation to Invoice Example
An illustrative steel fabrication supplier in Peenya, Bengaluru quotes a packaging unit in Bhiwandi, Maharashtra in July 2026. The buyer sits in another state, so the tax lands as IGST.
Note: this is an invented example for illustration only. The supplier, buyer, document numbers and figures are all made up.
Between 6 July and 24 July the money never moved. What changed is the legal status of the paper, and with it the buyer’s right to claim credit. A GST invoice value calculator checks that tax line.
What GST Law Expects at the Invoice Stage
Timing is not left to you. Section 31 of the CGST Act puts the invoice for goods before or at the time of removal, Rule 47 allows 30 days from the supply of a service, and Rule 46 lists every particular the document must carry.
Scale adds a second layer. Under Notification 10/2023-Central Tax, sellers above Rs 5 crore aggregate turnover must register each B2B invoice on the Invoice Registration Portal for an IRN, so e-invoicing is part of the same step. Since 1 April 2025, anyone at Rs 10 crore and above gets 30 days to report it, and a late invoice is rejected outright, taking the buyer’s credit with it.
Notifications sit on the CBIC GST portal, and a GST return filing checklist keeps the monthly side honest.
Run the Best E-Invoicing Software
Those deadlines are the part owners underestimate. A quote can sit in an inbox for weeks, but the moment it converts, the invoice is on a clock that does not care how busy the week was.
For retail businesses, Petpooja Invoice generates e-invoices and e-way bills, tracks GST liability in real time, and runs it off centralised inventory. For restaurants, Petpooja POSS covers the same ground at the billing counter.
The best e-invoicing software earns its keep on the days you are behind, when a converted quote still has to reach the portal in time. See how Petpooja Invoice works and picture your busiest week running through it.
Frequently Asked Questions
No. Section 16(2)(a) of the CGST Act allows credit only against a tax invoice or debit note, so a quote, a proforma invoice or an estimate buys nothing at the GST portal. Credit starts only once the tax invoice is issued.
Only if the buyer asks for one, usually to release an advance or open a letter of credit. Plenty of Indian SMEs go straight from an accepted quote to the tax invoice, which is perfectly valid.
Different documents, different series. Rule 46 requires a consecutive serial number of up to sixteen characters, unique for the financial year, so QT-2026/207 cannot double as an invoice number. Quote it as a reference line instead.
There is no limit tied to the quote itself, but the law ties the invoice to the supply: Section 31 says goods before or at removal, and Rule 47 gives 30 days for services. The quotation’s own validity date is a commercial promise, not a tax deadline.
Say the buyer confirms 30 cable trays instead of 40. Bill the quantity actually supplied, not the quoted one, and let the purchase order carry the change so your invoice, your stock and the buyer’s records agree.
