Invoice and Quotation Format for Small Business in India

What a GST invoice must contain, how to number invoices correctly, what a quotation should include, and the e-invoicing rules that apply in 2026.

Published 13 October 2026 by Web Hippo in Industry Insights

Not tax advice This is a practical summary of published rules for small businesses, written by a marketing team rather than tax professionals. Rules change and exceptions apply. Confirm the current requirements with your chartered accountant and on the CBIC website before you finalise your invoice format.

Most invoice problems in small businesses come from two things: a missing mandatory field, which creates a headache for the customer claiming input tax credit, and invoice numbering that restarts unpredictably. Both are easy to fix once, and then never think about again.

Below is what a GST invoice must contain, how to number invoices, what belongs on a quotation, and which businesses have to generate e-invoices.

What a GST Tax Invoice Must Contain

Rule 46 of the CGST Rules, 2017 sets out the particulars of a tax invoice. In plain terms:

Exports carry an additional endorsement stating whether the supply is made on payment of integrated tax or under bond or Letter of Undertaking without payment, along with the destination country. You can read the rule text on CBIC's tax information portal.

When you issue a bill of supply instead

A bill of supply replaces a tax invoice when you cannot charge GST: composition scheme dealers, and supplies that are exempt, nil-rated or non-taxable. It carries similar details minus the tax breakup. Composition dealers must also print that they are a composition taxable person not eligible to collect tax on supplies.

Invoice Numbering That Does Not Cause Problems

The rule is a consecutive serial number, no longer than 16 characters including any prefix and separators, unique within the financial year. Only hyphens and slashes are allowed as special characters.

  • <strong>Do not reuse numbers</strong> within a financial year, even after cancelling an invoice.
  • <strong>Do not leave gaps</strong>, because unexplained gaps invite questions during scrutiny.
  • <strong>Restart the series</strong> at the start of each financial year, with the year in the number so the two are never confused.
  • <strong>Keep separate series</strong> for invoices, credit notes, debit notes and bills of supply.

Do You Need to Generate e-Invoices?

e-Invoicing means reporting an invoice to the Invoice Registration Portal to get an Invoice Reference Number and a QR code, and it applies to business-to-business supplies. The threshold has been ₹5 crore of aggregate turnover since 1 August 2023, and it is triggered if your turnover exceeded that in any financial year from 2017-18 onwards.

If you are close to a threshold, set the process up before you cross it. Businesses that discover the requirement late usually find their billing software needs changing mid-year.

Quotation and Proforma Invoice Format

GST law prescribes no format for a quotation or proforma invoice. Issuing one creates no tax liability, it is not reported in any return, and the customer cannot claim input tax credit against it. That freedom is exactly why quotations should be written carefully: they set expectations and they are what the customer compares.

The line that prevents most scope arguments Add an "Excludes" block to every quotation: travel, third-party licences, ad spend, printing, revisions beyond a number you name. Customers rarely object at quotation stage, and it settles the argument that would otherwise arrive with the final invoice.

Practical Habits Worth Adopting

  • <strong>Send the invoice the day the work completes,</strong> not at month end. Payment timelines start when the invoice arrives.
  • <strong>Put a payment link on the invoice,</strong> whether UPI QR or a payment gateway link. It measurably shortens collection time.
  • <strong>Follow up on WhatsApp,</strong> where invoices actually get seen. Our message templates include payment reminder wording.
  • <strong>Keep digital copies for the statutory retention period</strong> and back them up outside your laptop.
  • <strong>Use accounting software</strong> rather than editing a Word file. Manual files are where duplicate numbers and missing fields come from.

If you are quoting for marketing or web projects, our proposal template covers the document that goes with the quotation, and the website cost guide covers realistic pricing for web work in India.

Frequently Asked Questions

<em>Summarised from the CGST Rules and published GST notifications, last checked September 2026.</em>

This article was written by Web Hippo, a goal-based digital marketing agency in Hyderabad, India. Get in touch for a custom growth strategy.