Context
A GST tax invoice is not a free-form receipt — Rule 46 of the CGST Rules[1] fixes a specific list of particulars it must carry, and Section 31 of the CGST Act[2] makes issuing one mandatory for a registered supplier making a taxable supply. The annotated invoice above labels each Rule 46 field on a worked example, so a business can check its own template against the statute clause by clause.
The supplier-side fields come first: the supplier's name, address, and GSTIN (Rule 46(a)), then a consecutive serial number unique for the financial year (Rule 46(b)) and the invoice date (Rule 46(c)). The number must run in an unbroken sequence — gaps and resets are an audit signal. Then the recipient block: the buyer's name, address, and, if registered, GSTIN (Rule 46(d)). Where the buyer is unregistered and the value is above the prescribed limit, Rule 46(e)–(f) still require the buyer's name, address, and state to be recorded.
The line-item fields carry the commercial substance: a HSN code for goods or SAC code for services (Rule 46(g)), the description (Rule 46(h)), the quantity (Rule 46(i)), and the total and taxable value (Rule 46(j)–(k)). On the tax side, Rule 46(l)–(m) require the rate and the amount of tax, shown as the split into CGST and SGST for an intra-state supply or a single IGST line for an inter-state supply. Rule 46(n) requires the place of supply together with the state name for an inter-state transaction — the field that decides which tax applies. Rule 46(p) requires a flag stating whether the tax is payable on reverse charge. Finally Rule 46(q) requires the signature or digital signature of the supplier or an authorised representative. Rule 46(r) adds one further particular, a QR code carrying the Invoice Reference Number, but only where the invoice is issued as an e-invoice under Rule 48(4). Rule 46(s) then requires a declaration that the invoice is not required to be issued as an e-invoice under Rule 48(4), for a supplier whose turnover crosses the e-invoice threshold but who is exempt from e-invoicing and issues a normal tax invoice instead.
A document missing these particulars is not a valid tax invoice, and a buyer relying on it for input tax credit under Section 16 is exposed if the invoice cannot survive scrutiny. For high-turnover suppliers the fields are also the data the e-invoicing portal validates before returning an Invoice Reference Number. Getting the anatomy right at template level is what makes every downstream GST step — ITC, return reconciliation, audit — mechanical rather than contested.