Section 31 – Tax Invoice

Section 31 – Tax Invoice

(Section 31 of the Central Goods and Services Tax Act, 2017 – as amended up to 01 October 2025)

Section 31 of the Central Goods and Services Tax Act, 2017 (CGST Act) prescribes the statutory obligation relating to issuance of tax invoice, bill of supply, revised invoice, receipt voucher, refund voucher and payment voucher in respect of supplies made by a registered person. The provision determines the legally recognised point at which documentation must be generated for taxable supplies and thereby directly impacts the operation of Sections 9, 12, 13, 16 and 34 of the Act, along with Rules 46 to 55 of the CGST Rules, 2017.

The section is structured sub-section wise to address different transactional situations involving goods, services, continuous supply, advances, reverse charge and approval transactions.

Section 31(1) – Tax Invoice in Case of Supply of Goods

A registered person supplying taxable goods shall issue a tax invoice:

• Before or at the time of removal of goods for supply, where the supply involves movement; or
• Before or at the time of delivery or making available thereof, where the supply does not involve movement.

The statutory trigger is linked to the act of removal or delivery. “Removal” in commercial understanding refers to dispatch of goods from the supplier’s place of business or any other place from which supply is effected. The law does not permit issuance of invoice at a later stage once goods have been removed.

This provision applies to all taxable supplies of goods, including outward supplies made for consideration in the course or furtherance of business.

Section 31(2) – Tax Invoice in Case of Supply of Services

In the case of taxable services, the registered person shall issue a tax invoice:

• Before or after provision of service,
• But within the prescribed time limit.

The prescribed time limit is governed by Rule 47 of the CGST Rules, 2017, which presently provides:

• Within 30 days from the date of supply of service;
• Within 45 days in case of banking companies, financial institutions, NBFCs and certain insurers.

Thus, unlike goods, invoice issuance for services is linked to provision of service subject to an outer statutory limit.

Section 31(3) – Special Documentary Requirements

Sub-section (3) addresses specific statutory situations where alternative documentation is required.

(a) Revised Invoice

Where registration is granted under Section 25 with effect from a retrospective date, the registered person may issue a revised invoice against supplies made between the effective date of registration and the date of issuance of the registration certificate. Such revised invoice must be issued within one month from the date of issuance of registration certificate.

(b) Bill of Supply

A registered person shall issue a bill of supply instead of a tax invoice in the following cases:

• Supply of exempt goods or services;
• Person paying tax under Section 10 (Composition Levy).
• No tax component is separately indicated in a bill of supply.

(c) Receipt Voucher

Where a registered person receives advance payment in respect of any taxable supply, he shall issue a receipt voucher evidencing receipt of such payment.

(d) Refund Voucher

Where advance has been received and subsequently no supply is made and the amount is refunded, a refund voucher shall be issued against such refund.

(e) Payment Voucher (Reverse Charge)

In respect of supplies on which tax is payable under reverse charge mechanism, the recipient shall issue a payment voucher at the time of making payment to the supplier.

Further, where the supplier is unregistered and reverse charge is applicable, the recipient is required to issue an invoice in respect of such supply in accordance with the relevant provisions read with Rule 46.

Section 31(4) – Continuous Supply of Goods

In case of continuous supply of goods, where successive statements of accounts or successive payments are involved, the invoice shall be issued:

• Before or at the time each statement is issued; or
• Before or at the time each payment is received.

“Continuous supply of goods” refers to supply provided continuously or on recurrent basis under a contract, whether by means of a wire, cable, pipeline or otherwise, and for which the supplier invoices the recipient on a regular or periodic basis.

Section 31(5) – Continuous Supply of Services

In case of continuous supply of services, invoice issuance depends upon contractual structure:

• If due date of payment is ascertainable → invoice shall be issued on or before the due date of payment;
• If due date not ascertainable → invoice shall be issued before or at the time of receipt of payment;
• If payment linked to completion of an event → invoice shall be issued on or before completion of that event.

Continuous supply of services generally includes long-term service contracts, subscription services, annual maintenance contracts and construction-related arrangements.

Section 31(6) – Cessation of Supply Before Completion

Where supply of services ceases before completion under a contract, the invoice shall be issued at the time when supply ceases, to the extent of supply made before such cessation.

This provision ensures that tax liability is not deferred due to premature termination of contract.

Section 31(7) – Goods Sent on Approval for Sale or Return

Where goods are sent on approval for sale or return, the invoice shall be issued:

• Before or at the time of supply; or
• Within six months from the date of removal,

whichever is earlier.

If approval is not received within six months from the date of removal, the supply is deemed to have taken place on the date of removal and tax invoice must be issued accordingly.

Mandatory Particulars of Invoice

Every tax invoice issued under Section 31 must contain particulars prescribed under Rule 46 of the CGST Rules, 2017, including:

• Name, address and GSTIN of supplier;
• Consecutive serial number and date of issue;
• Name, address and GSTIN/Unique ID of recipient (where registered);
• Description of goods or services;
• Quantity (for goods) and value;
• Rate and amount of tax (CGST, SGST/UTGST, IGST, Cess);
• Place of supply (in case of inter-State supply);
• Signature or digital signature of supplier.

Failure to comply with invoice requirements may attract penalty under Section 122 and may affect ITC entitlement under Section 16(2).

Electronic Invoicing (E-Invoicing)

Where notified under Section 31 read with Rule 48(4), certain classes of registered persons are required to issue invoice by obtaining an Invoice Reference Number (IRN) from the Invoice Registration Portal (IRP). An invoice issued without compliance with notified e-invoicing requirements shall not be treated as a valid invoice.

The applicability threshold and notified class of persons are determined through Government notifications issued from time to time.

Relationship with Time of Supply

The date of invoice issued under Section 31 directly affects determination of time of supply under:

• Section 12 – Time of supply of goods;
• Section 13 – Time of supply of services.

Therefore, delayed or incorrect issuance of invoice may alter tax period and give rise to interest liability under Section 50.

Summary Structure of Section 31

Section 31 covers the following statutory aspects:

• Tax invoice for goods
• Tax invoice for services
• Revised invoice
• Bill of supply
• Receipt voucher
• Refund voucher
• Payment voucher (reverse charge)
• Continuous supply of goods
• Continuous supply of services
• Cessation before completion
• Goods sent on approval basis
• Prescribed invoice particulars
• E-invoicing compliance