GST Invoice Format: Mandatory Fields Explained

People often search for “the” GST invoice format as if there were one official form to fill in. There is not. The law lists the details a tax invoice must contain, and you are free to lay them out however you like, as long as every required detail is present and readable. That list lives in Rule 46 of the CGST Rules, 2017, issued under Section 31 of the CGST Act, 2017. This guide goes through each field, explains when it applies, and shows how the format changes between B2B and B2C bills.

This is general guidance, not legal or tax advice. Notifications can change details such as HSN requirements, so check anything specific with your CA.

The mandatory fields under Rule 46

Here is the full list of particulars, in plain language, with a note on when each one applies.

Let us look at the fields that cause the most confusion.

Supplier details

Your legal name (as on the GST certificate), your trade name if you use one, your address and your 15-character GSTIN. The first two digits of the GSTIN are your state code, which is how a reader can tell at a glance whether a sale is intra-state.

Invoice number

Rule 46(b) asks for a consecutive serial number, not exceeding 16 characters, in one or multiple series. It may contain letters, numerals, hyphens and slashes, and it must be unique for the financial year. A financial-year tag in the number, like SHOP/26-27/0123, is a simple way to keep numbers unique when you restart the count each April.

HSN and SAC codes

Notification 78/2020-Central Tax sets the digits by aggregate turnover in the previous financial year:

Services use SAC codes in the same column.

Taxable value and discount

The taxable value is the value on which GST is calculated. Rule 46 asks you to show it after taking discount into account. If you give 10% off on the bill, GST is charged on the discounted amount, and the invoice should make that clear.

Tax rate and amount

Show the rate and the amount separately for each tax head that applies. For an intra-state sale that is CGST and SGST (each half of the GST rate). For an inter-state sale it is IGST at the full rate. Where compensation cess applies to an item, it is shown too.

Place of supply

For inter-state supplies the invoice must state the place of supply along with the name of the state. Place of supply is what decides whether you charge CGST plus SGST or IGST. For goods sold over the counter, it is your shop’s location. For goods delivered to another state, it is usually where delivery ends.

Reverse charge

Most retail sales are under forward charge, so this line simply reads “No”. It exists for specific supplies where the buyer pays the tax.

B2B versus B2C: what changes

The core fields are the same, but a few details depend on who is buying.

B2B (buyer is registered):

• The buyer’s name, address and GSTIN are mandatory.
• HSN is mandatory (4 or 6 digits by turnover).
• If the sale is inter-state, IGST and the place of supply must be shown.
• If your aggregate turnover has exceeded ₹5 crore in any financial year since 2017-18, the invoice must be reported as an e-invoice to get an IRN.

B2C (buyer is unregistered):

• No buyer GSTIN.
• The buyer’s name and address are needed only when the taxable value is ₹50,000 or more.
• For sales below ₹200 where the buyer does not ask for an invoice, you may issue one consolidated invoice at the end of the day instead (Rule 46 proviso).
• The dynamic QR code requirement on B2C invoices applies only to businesses with aggregate turnover above ₹500 crore.

Related documents with their own formats

Not every sale uses a tax invoice:

• Bill of supply (Rule 49): issued by composition dealers and for exempt supplies. It has no tax columns. A composition dealer should print the declaration that they are a composition taxable person, not eligible to collect tax on supplies.
• Invoice-cum-bill of supply (Rule 46A): a single document when you sell both taxable and exempt items to an unregistered buyer.
• Estimate or quotation: not a tax document at all. It should not carry a tax invoice number, so it does not break your invoice series.

Copies

Rule 48 asks for three copies of an invoice for goods (ORIGINAL FOR RECIPIENT, DUPLICATE FOR TRANSPORTER, TRIPLICATE FOR SUPPLIER) and two for services (ORIGINAL FOR RECIPIENT, DUPLICATE FOR SUPPLIER).

A sample GST invoice layout

Below is a compact layout that covers the Rule 46 fields for an intra-state B2C sale from a shop. The same structure fits a thermal receipt or an A4 page.

            SRI LAKSHMI GENERAL STORES
        12, 4th Cross, Jayanagar, Bengaluru
        GSTIN: 29ABCDE1234F1Z5   FSSAI: 1122...
                   TAX INVOICE
Bill No: SLG/26-27/0458        Date: 12-10-2026
Customer: Walk-in
-------------------------------------------------
Item              HSN    Qty   Rate     Amount
Toor dal 1kg      0713    2   150.00    300.00
Phone charger     8504    1   250.00    250.00
-------------------------------------------------
Taxable value                            550.00
CGST                                      30.00
SGST                                      30.00
Grand total                             ₹610.00
Rupees Six Hundred Ten Only
-------------------------------------------------
GST %   Taxable    CGST    SGST
5%       300.00    7.50    7.50
18%      250.00   22.50   22.50
Reverse charge: No
Paid by UPI                 Authorised signatory

Notice the tax breakup table near the bottom. It is not listed by name in Rule 46, but it presents the rate-wise tax clearly and is what most accountants look for first.

Common format mistakes

• Gaps or repeats in invoice numbers. Cancelled bills should be marked void, not deleted, so the series stays consecutive.
• Tax on the pre-discount amount. GST goes on the value after discount.
• IGST on a local sale or CGST plus SGST on an inter-state sale. Check the place of supply.
• Composition dealers showing tax. A bill of supply never shows GST.
• Missing HSN on B2B bills. HSN is mandatory on B2B invoices for every turnover band.
• Over-long invoice numbers. Count the characters once you add the year tag and prefix.

How PaisaBill handles the format

PaisaBill prints the details a shop needs on every bill. You enter your GSTIN, legal name and, where relevant, FSSAI and CIN once, and your state is detected from the GSTIN. Each product carries an HSN code and GST rate, and the bill can show an HSN column, the CGST and SGST split, a tax breakup table and the amount in words. Bill numbers follow your rules: prefix, separator, 4 to 7 digits, start number, suffix, an optional financial-year tag and an optional restart each year. Voided bills stay on record with a reason, so the series has no gaps.

There are 24 templates: 15 thermal receipt designs for 58mm and 80mm paper, 3 kitchen order ticket layouts, and 6 A4 or A5 invoice designs, including “GST Tax Invoice” and an “Estimate/Quotation” layout for quotes.

PaisaBill currently prints CGST plus SGST bills for in-state sales. For an inter-state B2B tax invoice that needs IGST, the buyer’s GSTIN and place of supply, prepare it in your accounting software or with your CA.

For a step-by-step walkthrough of making the bill itself, read how to make a GST invoice. If you print on a roll printer, the thermal printer setup guide covers paper sizes and connections. Retailers can also read about billing software for retail shops.

Try it free

PaisaBill is free on Android, Windows and the web. Download PaisaBill and set up your GST invoice format in a few minutes.