Skip to content

GST · 26 June 2026

What Is the Value of Supply Under Section 15 of the CGST Act?

Value of supply is the amount GST is levied on. Under Section 15(1) of the CGST Act it is the transaction value, the price actually paid or payable for the supply, where the supplier and recipient are not related and the price is the sole consideration. Section 15(2) lists what must be added; Section 15(3) lists the discounts that may be deducted. Where transaction value cannot apply, the valuation Rules 27 to 35 step in.

In this section
Myth

GST is charged on the price printed in the “amount” box of the invoice, nothing more.

Fact

Section 15(2) of the CGST Act adds packing, commission, incidental charges, and interest for late payment into the value of supply. The taxable value can be higher than the bare product price.

What is the value of supply under GST?

Short answer

The value of supply is the figure GST is charged on. Under Section 15(1) of the CGST Act, it is the transaction value, the price actually paid or payable, when the parties are unrelated and price is the only consideration.

  • Transaction value is the default. GST applies the relevant rate to this value, so getting it wrong understates or overstates tax and the buyer’s input tax credit.
  • “Sole consideration” means money is the only thing changing hands. A part-exchange or barter breaks this test, and the valuation rules take over.
  • “Related persons” covers group companies, employer and employee, and others defined in the Act. Between related parties the transaction value is set aside.
  • The value is per supply, and it is the value before GST is added, not after.

What must be added to the value under Section 15(2)?

Short answer

Section 15(2) adds charges that sit alongside the price: taxes other than GST, third-party costs the buyer paid on the supplier’s behalf, incidental expenses, and interest or late fees for delayed payment.

Section 15(2) clauseAdded to the valueExample
15(2)(a)Taxes, duties, cesses other than GST, if charged separatelyA state levy billed on the same invoice
15(2)(b)Amounts the supplier was liable to pay but the recipient paidA freight bill the buyer settled directly
15(2)(c)Incidental expenses: packing, commission, anything charged at or before deliveryPacking and forwarding charges on the invoice
15(2)(d)Interest, late fee, or penalty for delayed paymentA 2% monthly charge on an overdue invoice
15(2)(e)Subsidies directly linked to the price, excluding central and state government subsidiesA manufacturer’s price-support subsidy

Source: Section 15(2), CGST Act 2017. Government subsidies are excluded; only price-linked non-government subsidies are added.

Which discounts can you deduct under Section 15(3)?

Short answer

Discounts recorded on the invoice at the time of supply are deducted from the value. A post-supply discount is deductible only if it was agreed before the supply, linked to specific invoices, and the buyer reverses the matching ITC.

  • Pre-supply discount: a trade or cash discount shown on the face of the invoice reduces the taxable value directly.
  • Post-supply discount: deductible only when all three conditions hold, an agreement before supply, a link to specific invoices, and ITC reversal by the recipient.
  • Why it matters: a year-end volume rebate that was not agreed up front cannot reduce the value, so GST stays charged on the original amount.
  • The value you settle here is the figure printed on the GST tax invoice as the taxable value under Rule 46(k).

What happens when the transaction value cannot be used?

Short answer

Where the parties are related or price is not the sole consideration, Section 15(4) and 15(5) push valuation to Rules 27 to 35, which use open market value or a cost-plus method.

  • Rule 27 covers consideration not wholly in money, using open market value first.
  • Rule 28 covers supplies between related or distinct persons, again starting from open market value.
  • Rules 30 and 31 fall back to cost plus 10% or a reasonable means consistent with the Act.
  • These rules are the exception. For an arm’s-length sale at a money price, Section 15(1) transaction value still governs.