CGST Act, 2017 - Chapter IV: Time and Value of Supply

Section 15 of CGST Act - Value of Taxable Supply

Section 15 lays down the basic GST valuation rule. In an ordinary arm's-length supply, where the supplier and recipient are not related and price is the sole consideration, GST is generally computed on the transaction value - the price actually paid or payable. The section also specifies additions, permitted discounts and situations where the prescribed valuation rules apply.

Law update as on 15 September 2026: The Finance Act, 2026 has enacted a change to the rules for post-supply discounts under section 15(3)(b), removing the pre-existing agreement and invoice-linking requirement and connecting the deduction to a credit note under section 34 and reversal of attributable input tax credit by the recipient. The amendment is to operate from a separately notified commencement date. Until that commencement takes effect, the presently operative wording reproduced below should continue to be checked for compliance.

What does "value of taxable supply" mean?

The value of taxable supply is the monetary value on which GST is calculated. Section 15 starts with transaction value. This method applies when two conditions are satisfied: the supplier and recipient are not related, and the price is the sole consideration.

If those conditions are not satisfied, or if the value cannot otherwise be determined under section 15(1), valuation moves to the methods prescribed in the CGST Rules. Important valuation provisions include Rules 27 to 35, dealing with non-monetary consideration, related or distinct persons, agents, cost-based valuation, residual valuation and specified special cases.

Section 15 - Value of Taxable Supply

Central Goods and Services Tax Act, 2017 - Section 15
(1) The value of a supply of goods or services or both shall be the transaction value, which is the price actually paid or payable for the said supply of goods or services or both where the supplier and the recipient of the supply are not related and the price is the sole consideration for the supply.
(2) The value of supply shall include -
  1. any taxes, duties, cesses, fees and charges levied under any law for the time being in force other than this Act, the State Goods and Services Tax Act, the Union Territory Goods and Services Tax Act and the Goods and Services Tax (Compensation to States) Act, if charged separately by the supplier;
  2. any amount that the supplier is liable to pay in relation to such supply but which has been incurred by the recipient of the supply and not included in the price actually paid or payable for the goods or services or both;
  3. incidental expenses, including commission and packing, charged by the supplier to the recipient of a supply and any amount charged for anything done by the supplier in respect of the supply of goods or services or both at the time of, or before delivery of goods or supply of services;
  4. interest or late fee or penalty for delayed payment of any consideration for any supply; and
  5. subsidies directly linked to the price excluding subsidies provided by the Central Government and State Governments.

Explanation: For this sub-section, the amount of subsidy shall be included in the value of supply of the supplier who receives the subsidy.

(3) The value of the supply shall not include any discount which is given -
  1. before or at the time of the supply if such discount has been duly recorded in the invoice issued in respect of such supply; and
  2. after the supply has been effected, if -
    1. such discount is established in terms of an agreement entered into at or before the time of such supply and specifically linked to relevant invoices; and
    2. input tax credit as is attributable to the discount on the basis of document issued by the supplier has been reversed by the recipient of the supply.
(4) Where the value of the supply of goods or services or both cannot be determined under sub-section (1), the same shall be determined in such manner as may be prescribed.
(5) Notwithstanding anything contained in sub-section (1) or sub-section (4), the value of such supplies as may be notified by the Government on the recommendations of the Council shall be determined in such manner as may be prescribed.
Explanation - Related persons: Persons shall be deemed to be related if they are officers or directors of one another's businesses; legally recognised partners in business; employer and employee; a person directly or indirectly owns, controls or holds 25 percent or more of the outstanding voting stock or shares of both; one directly or indirectly controls the other; both are directly or indirectly controlled by a third person; together they directly or indirectly control a third person; or they are members of the same family. The term "person" includes legal persons. A sole agent, sole distributor or sole concessionaire relationship also causes the persons to be deemed related where the statutory condition is met.

What must be added to the transaction value?

Section 15(2) itemValuation treatment
Other taxes, duties, cesses, fees and chargesIncluded when charged separately, except the GST enactments and Compensation Cess specified in the section.
Supplier's liability paid by recipientIncluded where the recipient incurs an amount that the supplier was liable to pay and it is not already in the price.
Incidental expensesCommission, packing and pre-delivery or pre-supply charges by the supplier form part of value.
Delayed-payment chargesInterest, late fee or penalty for delayed consideration is included.
Price-linked subsidiesIncluded, except subsidies provided by the Central Government or State Governments.

Discounts under Section 15(3)

Discount before or at the time of supply

A discount given before or at the time of supply can be excluded from value if it is duly recorded in the invoice. The taxable value is therefore the net invoice value after the qualifying discount.

Post-supply discount - present operative framework

Under the existing wording, a post-supply discount is excluded only when it is established under an agreement entered into at or before the time of supply, is specifically linked to the relevant invoices, and the recipient reverses the input tax credit attributable to that discount.

Finance Act, 2026 amendment: The enacted amendment is intended to remove the requirement for a pre-supply agreement and specific invoice linkage. It instead refers to a credit note under section 34 and reversal of the attributable input tax credit. Because the GST amendment has a separate commencement mechanism, verify the notified effective date before applying the amended test to a transaction.

CGST Valuation Rules to read with Section 15

RuleSubjectCore approach
Rule 27Consideration not wholly in moneyOpen market value first; then money plus known monetary equivalent; then like kind and quality; thereafter Rules 30 and 31.
Rule 28Distinct or related persons, other than through an agentOpen market value, then like kind and quality, then Rules 30 and 31. Where the recipient is eligible for full ITC, the declared invoice value is deemed to be open market value.
Rule 29Goods supplied or received through an agentOpen market value or, at the supplier's option in the prescribed case, 90 percent of the onward price of like goods; otherwise Rules 30 and 31.
Rule 30Cost-based valuationGenerally 110 percent of cost of production, manufacture, acquisition or provision.
Rule 31Residual methodReasonable means consistent with section 15 and the valuation rules.
Rules 31A to 31DSpecified suppliesSpecial methods apply to notified categories, including prescribed gaming/casino situations and, from 2026, prescribed retail-sale-price valuation for specified tobacco and pan masala products.
Rule 32Certain services and second-hand goodsSpecial optional or prescribed methods for specified supplies.
Rule 33Pure agentQualifying expenditure incurred as a pure agent may be excluded when all prescribed conditions are met.
Rule 34Exchange ratePrescribes exchange-rate rules for valuation where consideration is in foreign currency.
Rule 35Value inclusive of taxProvides the formula for extracting tax where the value is inclusive of GST.

Section 15 expressly defines when persons are treated as related. This matters because the ordinary transaction-value rule in section 15(1) assumes that supplier and recipient are not related. Supplies between registrations of the same legal person in different States or Union territories are also treated as supplies between distinct persons under section 25 and are generally valued under Rule 28.

For a Rule 28 supply where the recipient is eligible for full input tax credit, the invoice value is deemed to be the open market value. This deeming rule is particularly important for inter-branch and head-office transactions.

Special valuation under Section 15(5)

Section 15(5) authorises the Government, on the recommendations of the GST Council, to notify supplies whose value is determined in the prescribed manner notwithstanding the normal transaction-value framework. Special valuation provisions therefore need to be checked for notified categories before relying only on invoice price.

From 1 February 2026, the valuation framework for specified pan masala and tobacco products was changed to a retail-sale-price based method through the relevant notification and rule amendments. Businesses dealing in notified goods should apply the special valuation provision rather than the ordinary transaction-value rule where the notification applies.

Simple examples

Example 1 - packing charged separately

Goods are sold for Rs. 1,00,000 and packing of Rs. 5,000 is separately charged by the supplier. Subject to the facts of the supply, the packing charge is an incidental expense under section 15(2)(c), so the value becomes Rs. 1,05,000 before GST.

Example 2 - invoice discount

The listed price is Rs. 50,000 and a Rs. 5,000 discount is given at the time of supply and recorded on the tax invoice. The qualifying discount is excluded and the taxable value is Rs. 45,000.

Example 3 - full ITC between related or distinct persons

Where Rule 28 applies and the recipient is eligible for full input tax credit, the value declared in the invoice is deemed to be the open market value, subject to the rule and the facts of the transaction.

Key compliance points