Convert Quotation to Invoice in Excel

Last updated: 27 June 2026

Converting a quotation to a tax invoice in Excel means transferring accepted line-item data into a separate invoice document, assigning a fresh consecutive invoice number from your GST series, and adding all mandatory Rule 46 fields — the quotation number stays on as a reference note, never as the invoice number.

Key takeaways

A quotation and a tax invoice are legally different documents; you cannot simply rename one as the other.
Under Rule 46 of the CGST Rules, a tax invoice must carry specific mandatory fields that a quotation is not required to have (GSTIN, Place of Supply, HSN/SAC, reverse-charge indicator, consecutive invoice number).
The invoice number must come from your own GST invoice series — consecutive and unique within the financial year.
Reference the accepted quotation number as a note on the invoice, not as the invoice number itself.
GST rates as of 2026: Nil, 5%, 18%, and 40% (the 12% and 28% slabs were abolished on 22 September 2025).
E-invoicing is mandatory above ₹5 crore aggregate turnover; the 30-day IRP upload window applies above ₹10 crore.
Keep the quotation PDF filed with the purchase order — that chain (quotation → PO → invoice) is your audit trail.

Why can't I just relabel my quotation as an invoice?

A quotation is a commercial offer. A tax invoice is a legal document under the GST Act that creates a tax liability and gives the buyer the right to claim Input Tax Credit (ITC). They differ in two important ways:

Legal standing. A quotation carries no mandatory GST fields. A tax invoice must satisfy Rule 46 of the CGST Rules or the recipient cannot claim ITC on it.

Numbering. Your GST invoice numbers must form a consecutive, unique series within each financial year. A quotation carries its own series (e.g., QT/2026-27/001). If you reuse that number as an invoice number, you break the GST sequence and create a compliance gap that can surface during scrutiny.

Fact box. Rule 46 of the CGST Rules, 2017 lists 16 mandatory particulars for a tax invoice. A quotation is governed only by general contract law — there is no mandatory GST format for quotations.

What fields must change when I convert a quotation to a tax invoice?

Run through this checklist before issuing any invoice from a quotation:

#	Field	Quotation	Tax Invoice
1	Document header	"QUOTATION"	"TAX INVOICE"
2	Document number	Quotation series (QT/…)	GST invoice series (INV/…) — next in sequence
3	Document date	Date of quote	Actual invoice date
4	Quotation reference	—	Note: "Against quotation no. QT/2026-27/001 dated DD-MMM-YYYY"
5	Buyer GSTIN	Optional	Mandatory for B2B
6	Place of Supply	Not required	Mandatory
7	HSN / SAC code	Optional	4 or 6 digits based on turnover
8	GST rate	Indicative	Confirmed and correct
9	Reverse charge	Not required	Yes / No
10	Validity clause	Present	Remove entirely
11	"Estimated" language	Common	Remove — amounts must be final
12	Payment terms	Tentative	Actual agreed terms

How do I do this in Excel — two practical approaches

Approach 1: Separate sheets in the same workbook (recommended)

This is the cleanest method for most small businesses.

Open your Excel workbook. Keep a "Quotation" sheet and an "Invoice" sheet side by side. Both use the same line-item structure, so copying is straightforward.
Mark the quotation as accepted. Add a note in cell A1 of the quotation sheet — for example, "Accepted by buyer on DD-MMM-YYYY" — so you have a record.
Copy line items to the Invoice sheet. Select the item rows (description, quantity, unit price, HSN/SAC, GST rate). Paste as values only (Ctrl + Shift + V → Values) so formulas do not carry over incorrectly.
Assign the next invoice number. In the Invoice sheet, enter the next number from your GST sequence. Never duplicate or skip a number.
Set the invoice date. Enter today's date, or the date of supply if the goods were delivered earlier.
Fill in Rule 46 fields. Confirm buyer GSTIN, Place of Supply, HSN/SAC codes, and the reverse-charge field.
Add the quotation reference note. In the remarks or notes section, type: Against your quotation no. QT/2026-27/001 dated DD-MMM-YYYY.
Remove quotation-only language. Delete any validity date, "estimated", or "subject to change" text.
Verify GST calculations. With current slabs (Nil / 5% / 18% / 40%), confirm the rate matches the HSN/SAC.
Save as PDF and issue. Print or export the Invoice sheet to PDF; file the original quotation PDF alongside it.

Approach 2: Single sheet with a type toggle (macro-enabled workbook)

If you prefer one template that handles both document types, add a dropdown in cell B1 with the values "Quotation" and "Tax Invoice". A short VBA macro then swaps the header and controls the invoice number field.

Sub ToggleDocumentType()
    Dim docType As String
    docType = Range("B1").Value

    If docType = "Tax Invoice" Then
        Range("A3").Value = "TAX INVOICE"
        Range("B5").Locked = False          ' Invoice number field — editable
        Range("C5").Value = ""              ' Clear any quotation reference number
        Range("G2").Value = "Remove validity date"
    Else
        Range("A3").Value = "QUOTATION"
        Range("B5").Locked = True           ' Lock invoice number — not applicable
        Range("C5").Value = Range("D5").Value ' Restore quotation number
        Range("G2").Value = ""
    End If

    ActiveSheet.Protect Password:="", UserInterfaceOnly:=True
End Sub

Assign this macro to a button labelled "Switch to Invoice". When the buyer confirms the order, click the button, enter the next invoice number, and the document is ready.

Fact box. The time of supply for goods under GST is the earlier of: the date of removal/delivery, or the date on which payment is received. For services, a tax invoice must be issued within 30 days of the supply. Issue the invoice promptly — a delayed invoice can affect the buyer's ITC eligibility.

What about partial deliveries — can one quotation produce multiple invoices?

Yes, and it is the correct approach. If a quotation covers ₹1,00,000 of goods delivered in two phases, issue two separate tax invoices — one for the first delivery (say ₹60,000) and one for the second (₹40,000). Do not issue a single invoice for the full quoted amount before goods are delivered; that would create a tax liability before the supply actually occurs.

In the notes field of each invoice, reference both the original quotation number and which phase it covers: Against quotation no. QT/2026-27/001 — Delivery 1 of 2.

When is e-invoicing required?

If your aggregate turnover crosses ₹5 crore in any preceding financial year, e-invoicing is mandatory. You must generate the invoice on the IRP (Invoice Registration Portal) and obtain an IRN and QR code before issuing the document to the buyer. Businesses above ₹10 crore must upload within 30 days of the invoice date.

A quotation-to-invoice workflow in Excel still applies — you fill in all fields in Excel first, then upload the JSON to the IRP. The template layout in this article maps to the IRP's required fields so no reformatting is needed.

Frequently asked questions

Can I use the quotation number as the invoice number? No. Quotation numbers belong to a separate series. Your GST invoice numbers must be consecutive and unique within the financial year. Using a quotation number as an invoice number breaks the required sequence and could be flagged during a GST audit.

Does the buyer need a copy of the original quotation? The law does not require you to attach the quotation to the invoice, but keeping both documents together is good practice. It supports your audit trail — especially if the buyer's accounts team needs to match the purchase order to the invoice.

What GST rate should I use if the rate changed between quotation date and invoice date? Apply the rate in effect on the date of supply (time of supply), not the date of the quotation. If the rate changed after you issued the quotation, inform the buyer before issuing the invoice. With only four slabs now in effect (Nil, 5%, 18%, 40%), verify against the current HSN/SAC rate schedule on the GST portal.

My quotation did not include HSN/SAC codes. Is that a problem? Not for the quotation itself — HSN/SAC is not mandatory on a quotation. But you must include it on the tax invoice. Look up the correct code on the GST HSN search tool before issuing.

How many copies of the tax invoice must I issue? For goods: three copies (original for buyer, duplicate for transporter, triplicate for supplier). For services: two copies (original for buyer, duplicate for supplier). Mark each copy accordingly.

Can I convert a proforma invoice to a tax invoice the same way? Yes. A proforma invoice is essentially a detailed quotation — it is not a GST tax invoice and creates no tax liability. The same conversion checklist applies: assign a fresh invoice number, add Rule 46 fields, and remove any "proforma" or "indicative" language.

How Ankeshan helps

How Ankeshan helps: Ankeshan pairs a Quotation sheet and Tax Invoice sheet with matching columns — copy a row, the invoice number increments, and a Rule 46 field checklist flags any blank mandatory fields before you print. It's launching soon; join the waitlist.

The free paired Quotation + Invoice Excel template requires no sign-up.

Sources

CGST Rules, 2017 — Rule 46 (Tax Invoice)
GST Council press release, 22 September 2025 (rate rationalisation — abolition of 12% and 28% slabs)
CGST Act, 2017 — Section 31 (Tax Invoice)
Notification No. 13/2020-Central Tax (e-invoicing applicability)
CBIC Circular on IRP 30-day upload rule (₹10 crore+ taxpayers)

General information, not professional advice. Verify on the official GST portal for your specific case. Reviewed by a Chartered Accountant; last updated 27 June 2026.