Sections 17, 18 and 19: Apportionment, Credit Transfer and the Wrong Head

Sections 17 explained: this guide covers what it means, who it applies to, the step-by-step process, documents required, fees, due dates and penalties in India — so you can stay compliant with confidence and avoid costly mistakes.

Three provisions that operate mostly out of sight — until a taxpayer charges the wrong head, at which point the third becomes the most useful section in the Act.

Section 17 of the IGST Act provides for the apportionment of integrated tax between the Centre and the States, and the settlement of funds — the mechanism by which IGST collected reaches the consuming State. Section 18 provides for the transfer of input tax credit between the integrated tax account and the central or State tax accounts on utilisation, so that the ledgers follow the credit. Section 19: where a registered person has paid integrated tax on a supply considered by him to be inter-State which is subsequently held to be intra-State, he shall be refunded the integrated tax in such manner and subject to such conditions as may be prescribed; and the converse where central and State tax was paid on a supply subsequently held to be inter-State.

Section 19 in practice: the wrong-head correction

The provision most taxpayers actually need.

Both directions are covered:

• IGST paid, held to be intra-State — the IGST is refunded, and CGST and SGST are paid;
• CGST and SGST paid, held to be inter-State — those are refunded, and IGST is paid.

And the crucial feature is in the corresponding CGST provision. Section 77 of the CGST Act deals with the same situation and provides that a registered person who has paid central and State tax on a supply subsequently held to be inter-State shall be refunded it, and — the key words — shall not be required to pay any interest on the amount of integrated tax payable. Section 77 →

So a wrong-head payment carries no interest cost, which is a significant concession: the tax was paid, merely to the wrong account, and the Act recognises that.

What it does not remove:

• the refund application under s.54, with its two-year limitation from the relevant date;
• the cash-flow gap while the correct head is paid and the wrong one refunded;
• the recipient's credit problem — CGST and SGST charged to a recipient in another State are not creditable to it at all;
• and the invoice correction, since the document must reflect the correct head.

The relevant date for a section 19 refund

Explanation (h) to s.54 of the CGST Act fixes the relevant date, for a refund of tax paid in a wrong-head situation, at the date of payment of the tax under the correct head.

Which is favourable. The two years runs not from the original wrong payment but from the date the correct payment is made — so a taxpayer discovering the error years later, who then pays correctly, has two years from that payment to claim the refund. The relevant date →

The practical sequence:

1. Identify the error and determine the correct head from the place-of-supply analysis.
2. Pay the correct tax, and record the date — it starts the refund clock.
3. Correct the invoice and inform the recipient, since their credit is affected.
4. File the refund of the wrongly paid tax within two years of that payment date.
5. Cite s.77 / s.19 and confirm that no interest is payable on the correct head.

Section 17: how IGST reaches the consuming State

IGST is collected by the Centre. GST is a destination-based tax, so the revenue on an inter-State supply must reach the State of consumption.

Section 17 is the mechanism. It provides for the apportionment of integrated tax between the Centre and the States in the situations it lists — including where the integrated tax is used to pay central tax or State tax, where credit is used for payment, and where the supply is to an unregistered person or a person not eligible for credit.

Why a taxpayer should care. Section 17 is administrative between governments, and no taxpayer files anything under it. But it explains why the place-of-supply rules are drafted as they are:

• s.10(1)(ca), making the invoice address the place of supply for B2C goods, so the revenue follows the consumer's State; Section 10(1)(ca) →
• s.12(14), apportioning government advertising by dissemination;
• the apportionment Explanations in s.12(3), 12(7), 12(11) and s.13(7);
• and s.9, attributing supplies in territorial waters to the nearest coastal State.

Each exists so that the settlement under s.17 sends the revenue to the right place. The elaborate place-of-supply machinery is, in the end, a revenue-allocation mechanism — which is also why place of supply is reserved to the Principal Bench of the Tribunal under the proviso to s.109(5), and why it is outside the advance ruling jurisdiction in s.97(2). Section 109 →

Section 18: credit transfer between accounts

The provision that makes cross-utilisation work.

Where integrated tax credit is used to pay central tax or State tax, or where central or State tax credit is used to pay integrated tax, the amount collected as one tax is being applied to another. Section 18 provides for the transfer between the accounts so that each government's account reflects what it is entitled to.

Again, no taxpayer files anything. What the taxpayer sees is the order of utilisation in ss.49, 49A and 49B of the CGST Act with Rule 88A — IGST credit must be exhausted first against IGST, and may then be used against CGST and SGST in any order; and CGST and SGST credit cannot be cross-utilised against each other. Order of utilisation →

The practical consequence of the order of utilisation is that a taxpayer with a large IGST credit and mostly intra-State outputs will exhaust IGST credit against CGST and SGST, while one with mostly inter-State outputs will use it against IGST — and the resulting balances in each head determine whether PMT-09 transfers or refunds are needed. PMT-09 →

Section 20: the CGST provisions applied

Section 20 of the IGST Act applies the provisions of the CGST Act to integrated tax mutatis mutandis, in the matters it lists — including scope of supply, composite and mixed supplies, time and value of supply, input tax credit, registration, returns, payment, refunds, audit, inspection, demands, appeals, offences and penalties.

So the IGST Act is a short Act: it deals with the levy, the place of supply, zero rating, apportionment and settlement, and borrows everything else.

Which is why almost every provision discussed across this cluster applies to IGST as it does to CGST — the demand provisions, the appeal machinery, the penalty provisions, the refund rules. The IGST Act adds the inter-State dimension and leaves the machinery to the CGST Act.

Key takeaways

• Section 19 with s.77 of the CGST Act corrects a wrong-head payment, with no interest on the correct head.
• The relevant date for that refund is the date of payment under the correct head — so the two years runs from then.
• The recipient's credit is still affected, and the invoice must be corrected.
• Section 17 apportions IGST so revenue reaches the consuming State — which is why the place-of-supply rules are drafted as they are.
• Section 18 transfers credit between accounts, while the taxpayer sees only the order of utilisation in ss.49, 49A and 49B.
• Section 20 applies the CGST machinery to integrated tax, which is why the IGST Act is so short.

Read next

• Section 77: Refund of Tax Paid Under the Wrong Head
• Sections 7 and 8: The Two-Step Inter-State Test
• Order of Utilisation: Sections 49A, 49B and Rule 88A
• The Relevant Date: Eleven Starting Points for Two Years

Disclaimer: Positions stated as on 5 September 2026, based on the IGST Act and the CGST Act and Rules as amended to 31 March 2026 (ICAI Bare Law, 12th edition).