What Fields Must a GST Tax Invoice Carry Under Section 31 and Rule 46?

Section 31 of the CGST Act makes it compulsory for a registered supplier to issue a tax invoice on every taxable supply. Rule 46 of the CGST Rules lists the exact particulars that invoice must carry. Any document missing those fields is not a valid tax invoice, and the buyer cannot claim input tax credit under Section 16.

By Mrs. Swapna Patel

Last reviewed

17 June 2026

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What makes a document a valid GST tax invoice?
Rule 46 field list: every mandatory particular
Which fields change for an unregistered buyer?
What happens if a field is missing?

Myth

Any document that shows a total and a GST number qualifies as a tax invoice for input tax credit.

Fact

A GST tax invoice must carry every field Rule 46 prescribes. One missing particular voids the ITC claim under Section 16.

What makes a document a valid GST tax invoice?

Short answer

Section 31 of the CGST Act requires every registered supplier making a taxable supply to issue a tax invoice. Rule 46 of the CGST Rules fixes the particulars it must carry. A document that omits any of those fields is not a valid tax invoice.

The obligation to issue sits with the supplier: Section 31 does not give the seller a choice on taxable supplies.
Rule 46 is an exhaustive list. Every clause is a hard statutory requirement.
The buyer bears the downstream risk: Section 16 permits input tax credit only against a valid tax invoice. If the invoice fails Rule 46, the credit is disallowed.
Composition suppliers and suppliers of exempt goods issue a bill of supply under Rule 49. Tax invoice rules do not apply to them.

Generate a tax invoice with every Rule 46 field

Rule 46 field list: every mandatory particular

Short answer

Thirteen fields across four blocks: supplier, recipient, line items, and tax. Each maps to a specific sub-clause of Rule 46.

Rule 46 clause	Field	Notes
46(a)	Supplier's name, address, GSTIN	GSTIN is mandatory. Name and address must match the GST registration.
46(b)	Consecutive invoice number	Up to 16 characters; must be unique for the financial year; serial breaks are an audit flag.
46(c)	Invoice date	Date of supply or date of issue, whichever applies under the time-of-supply rules.
46(d)	Recipient's name, address, GSTIN	Mandatory when the buyer is registered.
46(e)–46(f)	Unregistered buyer details	If the buyer is unregistered and the value is ₹50,000 or more, name, address, and state are required; below ₹50,000 only on request.
46(g)	HSN code (goods) or SAC code (services)	HSN digits required depend on annual turnover tier; SAC for every service line.
46(h)	Description of goods or services	Must name the goods or service, not just a category code.
46(i)	Quantity and unit of measure	For goods; not applicable for pure-service invoices.
46(j)	Total value of supply	Gross value of the goods or services supplied.
46(k)	Taxable value	Value of supply after any discount, net of GST.
46(l)–46(m)	GST rate and tax amount	Split into CGST + SGST for intra-state; IGST for inter-state. Show rate and rupee amount.
46(n)	Place of supply + state name	Required on inter-state supplies; determines whether IGST or CGST/SGST applies.
46(o)	Place of delivery (if different)	Relevant where the delivery address differs from the billing address.
46(p)	Whether tax is on reverse charge	Flag must appear even when the answer is "No". Absence is a compliance gap.
46(q)	Signature or digital signature	Of the supplier or an authorised signatory. Required on every invoice.

Source: Rule 46, CGST Rules 2017 (consolidated). Clause letters follow the consolidated rule; HSN digit requirements vary by turnover tier per CBIC notification, so check your registration tier before finalising your template.

Every labelled field above maps to a specific Rule 46 clause. A template missing any one of them is not a valid tax invoice.

Which fields change for an unregistered buyer?

Short answer

When the buyer is unregistered and the invoice value exceeds ₹50,000, Rule 46(d) requires the buyer's name, address, and state. Below that threshold, those fields may be omitted.

The ₹50,000 threshold applies per invoice, not per transaction series. A single invoice above the limit triggers the full recipient-detail requirement.
For B2C supplies below ₹50,000 to unregistered buyers, the invoice can show "Unregistered" in the GSTIN field; the other recipient fields are optional.
E-invoicing under the IRP (Invoice Registration Portal) requires the GSTIN field to be populated when both parties are registered; the portal rejects a blank GSTIN for a B2B transaction.
See pakka bill vs kaccha bill for how the registered/unregistered distinction drives the choice between a tax invoice and a bill of supply.

What happens if a field is missing?

Short answer

A tax invoice missing a Rule 46 field is not a valid tax invoice. The buyer's input tax credit claim under Section 16 is at risk.

GST officers can disallow ITC at audit if the invoice presented does not carry all Rule 46 particulars.
A gap in the invoice number sequence surfaces in GSTR-1 reconciliation; GST officers read it as a suppression signal.
A missing reverse-charge flag on Rule 46(p) is itself a compliance gap, even when the actual liability is zero.
For high-turnover suppliers above ₹5 crore from FY 2024-25, e-invoicing through the IRP validates Rule 46 fields before issuing an Invoice Reference Number (IRN). A document without an IRN is not a valid tax invoice for those suppliers.
A pakka bill generator fills every Rule 46 field automatically, so the invoice carries the full field set from the first download.

Build a Rule 46-complete invoice in 60 seconds

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Last reviewed: 17 June 2026