GST Invoice Format Rules: Rule 46 Mandatory Fields

If a customer, your accountant or a GST officer looks at one of your bills, the first thing they check is whether it follows the GST invoice format rules. Under Rule 46 of the CGST Rules, 2017, a tax invoice has to carry a fixed list of particulars, and an invoice that misses a GSTIN, a place of supply or the right invoice number can cause trouble for both you and your buyer. This guide walks through every mandatory field in plain language, shows how B2B and B2C bills differ, and ends with a checklist you can use to test your own invoice today.

GST invoice format rules: a tidy shop billing counter with a receipt printer, calculator, pen and laptop — Every tax invoice your counter prints must carry the particulars listed in Rule 46.

Where the GST invoice format rules come from

There is no single government-designed invoice template that every shop must copy. Instead, the law tells you what an invoice must contain, and you are free to choose the layout, colours and logo. Three pieces of law matter for a retail or wholesale business:

Section 31 of the CGST Act says a registered person supplying taxable goods or services must issue a tax invoice, and sets out when it has to be issued.
Rule 46 of the CGST Rules lists the particulars a tax invoice must show. This is the core of the GST invoice format rules.
Rules 47 and 48 cover the time limit for service invoices and how many copies you prepare.

The official text is published on the CBIC GST portal. Rules are amended from time to time through notifications, so treat this article as a practical explainer and confirm specific cases with your tax consultant.

Mandatory fields on a GST tax invoice (Rule 46 checklist)

Here is every particular Rule 46 asks for, grouped the way it usually appears on a printed bill.

1. Supplier details

Your legal or trade name, full address and GSTIN.
Print the GSTIN exactly as it appears on your registration certificate. A single wrong character means your buyer cannot match the invoice when they claim credit.

2. Invoice number and date

A consecutive serial number of not more than 16 characters, in one or more series.
Only letters, numerals, hyphen (-) and slash (/) are allowed, in any combination.
The number must be unique for a financial year. Many shops prefix the year and counter, for example KCH/26-27/0001 for the Kochi counter, so numbers never repeat after 31 March.
The date of issue.

3. Recipient details

For a registered buyer: name, address and GSTIN (or UIN).
For an unregistered buyer where the taxable value is ₹50,000 or more: name and address of the recipient, the delivery address, and the name and code of the State.
For an unregistered buyer below ₹50,000: the same details only if the buyer asks for them to be recorded.

4. Item details

HSN code for goods or SAC for services. The number of digits depends on your aggregate turnover as notified by CBIC; under the current notification, businesses up to ₹5 crore turnover show at least 4 digits on B2B invoices and larger businesses show 6 digits.
Description of goods or services.
Quantity, with the unit or Unique Quantity Code (for example NOS, KGS, LTR, BOX).

5. Value and tax

Total value of supply.
Taxable value after any discount or abatement.
The rate of tax: CGST and SGST (or UTGST) for an intra-State sale, IGST for an inter-State sale, plus cess where it applies.
The amount of tax charged under each head.

6. Supply details

Place of supply with the State name, for inter-State supplies.
The delivery address, where it is different from the place of supply.
Whether tax is payable on reverse charge (a simple “Yes/No” line works).

7. Signature

Signature or digital signature of the supplier or an authorised person. A valid e-invoice issued electronically does not need a physical signature.

Most businesses also print the words “Tax Invoice” at the top. It makes the document type obvious and avoids confusion with quotations, delivery challans or a bill of supply.

Blank invoice sheet next to a ticked checklist on a clipboard, used to check mandatory GST invoice fields — Check one B2B and one B2C bill against the mandatory field list.

B2B vs B2C invoices: what changes

The same Rule 46 applies to both, but in practice the fields you fill in look different at the counter.

Point	B2B (registered buyer)	B2C (walk-in customer)
Buyer GSTIN	Mandatory	Not applicable
Buyer name and address	Mandatory	Needed when taxable value is ₹50,000 or more, or when the customer asks
HSN/SAC digits	As notified for your turnover	Lower requirement for smaller businesses under the current notification
Why accuracy matters	Your buyer claims input tax credit from it	Feeds your B2C summary in GSTR-1
E-invoice (IRN)	Required once your turnover crosses the notified threshold	Not generated through IRP; very large taxpayers print a dynamic QR code instead

For B2B sales, the invoice is what your customer relies on to claim credit, so a wrong GSTIN or a missing place of supply hurts their books as much as yours. If you sell to other States, our guide to IGST and inter-state billing explains how place of supply decides whether you charge IGST or CGST plus SGST.

The small-value exception for retail counters

For a sale under ₹200 to an unregistered customer who does not want a tax invoice, the law lets you skip an individual invoice and issue one consolidated tax invoice at the close of each day for all such sales. Many supermarkets and kirana stores still print a bill for every customer because it is simpler to run and gives the customer proof of purchase, but the option exists.

When to use a bill of supply instead

A tax invoice is only for taxable supplies by a regular registered person. If you sell only exempt goods, or you are registered under the composition scheme, you issue a bill of supply instead, and a composition dealer must print the declaration that they are not eligible to collect tax. We have a separate guide on bill of supply vs tax invoice with the exact differences.

Distributor office desk with an invoice layout on screen, a printer and stacked cartons behind — B2B buyers rely on your invoice to claim input tax credit, so details must be exact.

Timing, copies and special cases

When the invoice must be issued

Goods: before or at the time the goods are removed for supply, where the supply involves movement; otherwise at the time of delivery.
Services: within 30 days of supplying the service (longer limits apply to banks and some financial institutions).

How many copies

Goods: three copies, marked “Original for Recipient”, “Duplicate for Transporter” and “Triplicate for Supplier”.
Services: two copies, “Original for Recipient” and “Duplicate for Supplier”.

Exports

An export invoice must carry an endorsement stating whether the supply is made on payment of IGST or under bond or letter of undertaking without payment of IGST.

E-invoicing

Once your aggregate turnover crosses the threshold notified by CBIC (currently ₹5 crore in any financial year), B2B invoices must be reported to the Invoice Registration Portal to get an IRN and QR code. The Rule 46 particulars still apply; e-invoicing only changes how the invoice is reported and validated.

A sample annotated invoice: what to look for

Imagine a hardware wholesaler in Thrissur selling paint and fittings to a registered contractor in Palakkad. Reading the invoice from top to bottom, you should be able to tick off:

Header: “Tax Invoice”, the wholesaler’s name, address and GSTIN starting with Kerala’s State code 32.
Number and date: something like TSR/26-27/0457, unique for the year and well under 16 characters.
Bill-to block: the contractor’s name, address and GSTIN.
Ship-to block: the site address, if it is different from the billing address.
Item lines: description, HSN code, quantity with unit, rate, discount and taxable value for each item.
Tax columns: CGST and SGST rate and amount on each line, because both parties are in Kerala. If the buyer were in Tamil Nadu, these would be replaced by IGST.
Footer: totals, reverse charge “No”, place of supply “Kerala (32)”, and an authorised signature.

If any of these is missing or hand-corrected, fix the template rather than the individual bill.

Neat row of teal files and a box of printed invoices kept in serial order in a shop back office — Keep invoice numbers consecutive and unique for each financial year.

Common mistakes and a 5-step fix

These are the problems we see most often on shop invoices:

The invoice series restarts at 1 every month, so numbers repeat within the same financial year.
Two counters share one series and print duplicate numbers on the same day.
HSN codes are missing or entered at the wrong number of digits.
IGST is charged on a local sale (or CGST and SGST on an inter-State sale).
The buyer GSTIN is typed by hand on every bill, leading to typos.
Discounts are shown after tax, so the taxable value is wrong.

To clean this up:

Print one recent B2B bill and one B2C bill and check them against the Rule 46 list above.
Set up separate invoice series for each branch or counter, with a year prefix.
Add HSN codes and units to your item master once, so every bill picks them up automatically.
Save customer GSTINs and States in the customer master so tax type and place of supply are decided by the software, not by memory.
Review a sample of bills with your accountant each quarter, especially after a rate change or a new notification.

Billing software makes these rules much easier to follow, because the format is set up once and applied to every bill. Our guide to GST billing software for retail shops in India covers what to look for, and GST invoice software for shops goes deeper into invoice layouts and printing.

If you want invoices with GSTIN, HSN codes, tax splits and barcode billing built in, try Caddayn Biller. It runs as a Windows app and a web app, supports multiple branches, and keeps your billing and inventory in one place.

FAQ

Is there an official GST invoice format I must use?

No. The government does not prescribe one fixed design. Your invoice is valid as long as it contains all the particulars required by Rule 46, in any clear layout.

How long can a GST invoice number be?

Up to 16 characters, using letters, numerals, hyphens and slashes. It must be consecutive within its series and unique for the financial year.

Do I need the customer’s name on a B2C invoice?

Only when the taxable value is ₹50,000 or more, or when the customer asks for their details to be recorded. Below that, a walk-in bill without the customer’s name is fine.

Can I handwrite a GST invoice?

A handwritten invoice is acceptable if it has every mandatory field and follows a proper serial number, unless you are covered by e-invoicing. In practice, software-generated bills cut down errors in numbering, HSN codes and tax calculations.

What happens if a mandatory field is missing?

Your buyer may face problems claiming input tax credit, and you may have to issue corrected documents or face penalties for an improper invoice. Fixing the template is the best way to prevent this.

This article is general information, not tax or legal advice. Rules and thresholds change through notifications, so check the latest position with your tax consultant.

GST Invoice Format Rules (Rule 46): Mandatory Fields Checklist