GST Invoicing Services

GST Invoicing — The Statutory Backbone

Invoicing is the foundation of GST compliance. Section 31 of the CGST Act read with Rule 46 of the CGST Rules prescribes the mandatory contents of a tax invoice, the time within which an invoice must be issued, and the special documents required for specific transactions. Errors in invoicing flow directly into GSTR-1, GSTR-3B, e-way bills, and e-invoicing — and they are among the most common reasons for input tax credit denial and demand notices.

Beyond compliance, a clean invoicing setup also strengthens working capital — accurate invoices accelerate payment cycles, simplify reconciliation, and protect against ITC challenges by recipients. We help businesses implement an end-to-end invoicing framework that is statute-compliant, audit-ready, and operationally efficient.

Mandatory Fields in a GST Tax Invoice (Rule 46)

• Name, address, and GSTIN of the supplier.
• Consecutive serial number not exceeding 16 characters, unique for each financial year.
• Date of issue of the invoice.
• Name, address, and GSTIN / UIN of the recipient (B2B); name and address for B2C above ₹50,000.
• HSN code of goods or SAC of services (4 / 6 / 8 digits as per turnover and supply type).
• Description, quantity (with unit), and total taxable value.
• Rate of tax (CGST, SGST, IGST, UTGST, cess) and amount of tax charged separately.
• Place of supply, along with State name and code, for inter-state supplies.
• Address of delivery if different from place of supply.
• Whether tax is payable on reverse charge basis.
• Signature or digital signature of the supplier or authorised representative.

Time Limits to Issue an Invoice

• Supply of goods involving movement: before or at the time of removal of goods for supply to the recipient.
• Supply of goods (no movement): before or at the time of delivery of goods or making available to the recipient.
• Supply of services: within 30 days from the date of supply of service.
• Banking, financial, and insurance services: within 45 days from the date of supply of service.
• Continuous supply of goods / services: on the date of issue of each statement / each payment, as applicable under Section 31(4) / (5).

Our GST Invoicing Services

Other GST Documents You Must Know

• Bill of supply (Rule 49): issued for exempt supplies or by a composition dealer in lieu of a tax invoice. See Composition for Goods.
• Revised invoice (Rule 53): issued for supplies made between the effective date of registration and the date of grant of registration.
• Credit / debit note (Section 34): to adjust value or tax, within the cut-off of 30 November of the following financial year or filing of the annual return, whichever earlier.
• Receipt voucher (Rule 50): on receipt of advance payment for supply of services.
• Refund voucher (Rule 51): where advance was received but no supply was made and tax invoice was not issued.
• Payment voucher (Rule 52): at the time of making payment to an unregistered supplier under reverse charge.
• Delivery challan (Rule 55): for movement of goods not on a tax invoice (job-work, supply on approval, transportation in batches, etc.).

HSN Digit Requirements

• Aggregate turnover up to ₹5 crore in previous FY: 4-digit HSN on B2B invoices; HSN on B2C optional.
• Aggregate turnover above ₹5 crore in previous FY: 6-digit HSN on all invoices, including B2C.
• Exports / imports / notified chemicals: 8-digit HSN required.
• SAC codes apply for services in a similar tiered manner.

Why Choose The Classic Partners

• End-to-end invoicing setup aligned with statutory and operational needs.
• ERP / Tally integration with HSN, SAC, and place-of-supply logic built in.
• Compliance package — invoicing + e-invoicing + e-way bill + returns.
• Audit-ready record-keeping with central digital storage of invoices and supporting documents.