What Goes Into the Value of Supply Under GST — and Which Charges Businesses Wrongly Leave Out
GST · Valuation · India · CGST Act 2017
What Goes Into the Value of Supply Under GST — and Which Charges Businesses Wrongly Leave Out
Your invoice says the goods cost ₹10,000. You charged ₹1,000 freight, ₹500 insurance and ₹300 packing, and you applied GST at 18 per cent on ₹10,000 because that is what the customer is buying. The department disagrees. Under Section 15 of the CGST Act, 2017, tax was payable on ₹11,800, and the shortfall carries interest and penalty. Value of supply is not the price on the product. It is the price plus everything the law bolts on to it, minus only two narrowly defined categories of discount.
Quick Summary
Value of supply is the transaction value under Section 15(1), but only where the parties are unrelated and price is the sole consideration. Section 15(2) then adds five categories of charge, including freight, packing, insurance, non-GST taxes and interest on delayed payment. Section 15(3) allows only two discount routes out. On a ₹10,000 base price with typical add-ons, the taxable value in our worked example rises to ₹12,150 and GST at 18 per cent to ₹2,187, not the ₹1,800 most sellers assume.
Why valuation decides more money than the rate does
Rate changes get the headlines. Valuation quietly moves more money, because it applies to every invoice regardless of which slab the goods fall into. When the 56th GST Council met on 3 September 2025 and collapsed the four-slab structure into 5 per cent, 18 per cent and a 40 per cent demerit rate from 22 September 2025, nothing in Section 15 changed. The base on which those rates apply was, and remains, the transaction value defined in 2017.
That base is enormous. The Finance Ministry reported gross GST revenue of roughly ₹22 lakh crore for FY 2025-26, an increase of about 8.3 per cent, with March 2026 alone crossing ₹2 lakh crore. Government data put active GST registrations at over 1.51 crore as of 30 April 2025. Every one of those registrations computes a taxable value on every invoice it raises, and valuation error is one of the most common findings in departmental audit.
Transaction value has two conditions, and both must hold
Section 15(1) says the value of a supply is the transaction value, meaning the price actually paid or payable. Most explainers stop there. The section does not. It attaches two conditions, and if either fails, the transaction value is discarded entirely and the valuation rules take over.
The first condition is that supplier and recipient must not be related. Related persons include group companies, entities with common directors, employer and employee, and anyone holding 25 per cent or more of the voting stock. It also captures distinct persons under Section 25, which means two branches of the same company registered in different states are treated as unrelated parties would never be.
The second condition is that price must be the sole consideration. If the buyer also transfers something of value that is not money, the price alone no longer represents what the supplier received. A printing press sold for ₹4,00,000 plus the buyer’s old machine is not a ₹4,00,000 supply.
Why the law is built this way
GST is an ad valorem tax. If the taxable base could be set by the parties themselves, related entities would simply invoice each other at a rupee and settle the real economics elsewhere. Section 15 therefore accepts a negotiated price only where the negotiation was genuinely at arm’s length, and hands everything else to a prescribed formula.
The five additions the law makes, whether you invoice them or not
Section 15(2) lists five clauses, and the operative word throughout is “shall”. These are not optional adjustments. Clause (a) pulls in any tax, duty, cess or fee charged under a law other than the GST Acts, if charged separately. Clause (b) captures any amount the supplier was liable to pay but which the recipient paid instead. Clause (c) is the widest: incidental expenses including commission, packing, and anything charged for something done before or at the time of delivery.
Clause (d) covers interest, late fee or penalty for delayed payment of consideration. Clause (e) brings in subsidies directly linked to the price, but only where the subsidy comes from someone other than the Central or a State Government.
Take a single illustrative invoice from a Pune parts manufacturer to a Nashik dealer, and watch every clause bite.
The two discounts that escape, and the one that keeps failing
Section 15(3) is the only relief valve. Clause (a) excludes a discount given before or at the time of supply, provided it is recorded in the invoice. That one is easy and rarely disputed. Clause (b) covers discounts given after the supply, and it has generated more litigation than any other line in the section.
As the provision stands today, a post-supply discount leaves the value only if three things are true together: it was established in an agreement entered into at or before the time of supply, it is specifically linked to the relevant invoices, and the recipient has reversed the input tax credit attributable to it. Miss any one and the supplier cannot reduce output tax, no matter how commercially real the rebate is.
This is where the legal position is genuinely in motion, and where most published material is now out of date. The GST Council recommended in September 2025 that the pre-agreement and invoice-linkage conditions be dropped. The Finance Act, 2026, which received assent on 30 March 2026, substituted Section 15(3)(b) to give effect to that, routing post-sale discounts through a Section 34 credit note with recipient credit reversal as the sole condition. But the amendment commences on a date to be notified, and no commencement notification had been issued as of mid-August 2026. Until one appears, the old three-condition test still governs every credit note you issue.
₹800 off · 15(3)(a)
₹800 off · 15(3)(b)
₹0 off · until notified
₹0 off · Circular 251
₹0 off · full tax
The distinction that resolves most disputes
Decide the credit-note type at design time, not at year end. A tax credit note under Section 34 reduces the supplier’s output tax and obliges the buyer to reverse credit. A financial or commercial credit note does neither. CBIC Circular 251/08/2025 confirmed that where a financial note is used, the recipient is not required to reverse input tax credit, because the original transaction value and tax were never reduced. Both are legal. Only one moves the tax.
Interest and penalties: the error hiding in almost every summary chart
Search for a diagram of Section 15 and you will very likely find interest on delayed payment listed as excluded from value of supply. It is not. Section 15(2)(d) expressly includes interest, late fee or penalty for delayed payment of consideration. The seller who lets a customer pay sixty days late and collects ₹250 of interest owes GST on that ₹250 at the rate applicable to the underlying supply, which on our example is ₹45.
Penalties for breach of contract are different, and the distinction is worth learning because it is subtle rather than arbitrary. Liquidated damages are outside the tax base, but not because Section 15 excludes them. They are outside because there is no supply at all. CBIC Circular 178/10/2022 dated 3 August 2022 explained that damages recovered to deter a breach are not consideration for tolerating anything; they are events in a contract, not its object.
The line runs like this. Money that compensates for something going wrong sits outside GST. Money paid for a facility the supplier granted, such as accepting late payment, early lease termination or loan prepayment, sits inside it. The same circular treats late payment charges as consideration for a facility naturally bundled with the principal supply, taxed at the principal supply’s rate.
What people actually get wrong
Three errors recur in audit. First, freight and insurance charged by the supplier are left out of the taxable value on the reasoning that they are reimbursements, when Rule 33’s pure agent test was never met. Second, delay interest is collected without tax. Third, a year-end rebate is passed by financial credit note and output tax is reduced anyway. Each is a valuation error, and valuation errors compound across every invoice in the period.
When transaction value fails, the rules run in a fixed order
Section 15(4) hands valuation to the CGST Rules whenever Section 15(1) cannot apply, and Chapter IV of those rules, Rules 27 to 35, supplies the method. The sequence is mandatory, not a menu. You may only descend to the next rung once the one above genuinely cannot be applied.
Rule 32 sits outside the ladder as an optional regime for specified supplies, and its percentages are worth memorising because they replace the transaction value entirely for the businesses they cover.
The money maths, line by line
Here is the full invoice, every clause identified, and the arithmetic shown. Apply the same layout to your own invoices and the exposure becomes visible in one pass.
| Charge or adjustment | In value? | Provision | Amount (₹) | GST at 18% (₹) |
|---|---|---|---|---|
| Base price of goods | Yes | Sec 15(1) | 10,000 | 1,800 |
| Freight charged by supplier | Yes | Sec 15(2)(c) | 1,000 | 180 |
| Transit insurance | Yes | Sec 15(2)(c) | 500 | 90 |
| Packing and forwarding | Yes | Sec 15(2)(c) | 300 | 54 |
| Cess under a non-GST state law | Yes | Sec 15(2)(a) | 150 | 27 |
| Testing fee owed by supplier, paid by buyer | Yes | Sec 15(2)(b) | 400 | 72 |
| Price-linked subsidy from an industry body | Yes | Sec 15(2)(e) | 600 | 108 |
| Trade discount recorded on the invoice | No | Sec 15(3)(a) | (800) | (144) |
| Subsidy from a State Government | No | Sec 15(2)(e) | 0 | 0 |
| TCS collected under the Income-tax Act | No | CBIC clarification | 0 | 0 |
| Reimbursement meeting the pure agent test | No | Rule 33 | 0 | 0 |
| Liquidated damages for breach | No | Circular 178/10/2022 | 0 | 0 |
| Taxable value on the invoice | — | Sec 15 | 12,150 | 2,187 |
| Interest for 60-day delay, billed later | Yes | Sec 15(2)(d) | 250 | 45 |
Worked example: the ₹432 gap
Metro Components invoices ₹10,000 of parts and charges GST of ₹1,800. Correctly valued, the supply is ₹12,150 and the tax is ₹2,187. The dealer later pays 60 days late and Metro collects ₹250 of interest without tax, missing another ₹45. Total understatement per invoice: ₹432. Across 400 invoices in a year that is ₹1,72,800 of tax, before interest under Section 50 and penalty.
Decoder: what each valuation term actually means
These are the terms that appear in notices, circulars and dealer agreements. Reading them precisely is most of the work.
| Term | What it actually means | What to do about it |
|---|---|---|
| Transaction value | Price actually paid or payable, valid only if parties are unrelated and price is sole consideration | Confirm both conditions before relying on your invoice price |
| Open market value | Full money value of an identical supply between unrelated parties, excluding GST | Document the comparable you used and keep the evidence |
| Like kind and quality | Comparable on characteristics, quality, quantity, function and reputation | Use only when no open market value exists |
| Distinct persons | Separate registrations of the same entity under Section 25, including branches | Value stock transfers under Rule 28, not at cost |
| Pure agent | Rule 33 status: payment authorised by recipient, shown separately, recovered at actuals with no markup | Excluded only if every condition is met; otherwise add it back |
| Secondary discount | A discount decided after the supply was made | Test against all three Section 15(3)(b) conditions |
| Tax credit note | Section 34 note that reduces taxable value and output tax | Report by 30 November following the financial year |
| Financial credit note | Commercial adjustment with no GST effect either side | Buyer keeps full credit; supplier keeps full liability |
| Margin scheme | Rule 32(5) valuation of second-hand goods at the sale-minus-purchase margin | Available only where no input tax credit was taken |
| Inclusive of tax | Rule 35 back-calculation where the price quoted already contains GST | Strip the tax before reporting taxable value |
Six checks before you file the return
Frequently asked questions
What exactly goes into the value of supply under GST?
The price actually paid or payable, plus five statutory additions under Section 15(2): non-GST taxes and cesses charged separately, amounts the supplier owed but the buyer paid, incidental expenses such as freight, packing, insurance and commission, interest or late fee for delayed payment, and price-linked subsidies from anyone other than the Central or a State Government. GST itself is never part of the value.
Is freight charged by the supplier included in the value of supply?
Yes. Section 15(2)(c) treats freight charged by the supplier as an incidental expense forming part of value, taxed at the rate applicable to the underlying goods. It leaves the value only where the supplier genuinely acts as a pure agent under Rule 33, meaning the buyer authorised the payment, it is shown separately, and it is recovered at exact cost with no markup.
Is interest on delayed payment taxable under GST?
Yes, and this is the most commonly misstated point. Section 15(2)(d) includes interest, late fee or penalty for delayed payment of consideration in the value of supply. CBIC Circular 178/10/2022 treats acceptance of late payment as a facility naturally bundled with the principal supply, so the interest carries the same rate as the goods or services it relates to.
Are penalties for breach of contract part of the value of supply?
No, but for a different reason than most summaries give. Liquidated damages escape not because Section 15 excludes them but because there is no supply. Circular 178/10/2022 held that amounts recovered to deter a breach are not consideration for tolerating an act. Do not extend that logic to late payment charges, which are taxable.
Can a post-supply discount reduce my GST liability?
Only under Section 15(3)(b), and only if the discount was established in an agreement made at or before the supply, is linked to specific invoices, and the recipient has reversed the attributable input tax credit. The Finance Act, 2026 relaxes the first two conditions, but it commences on a date to be notified and had not been brought into force as of mid-August 2026.
What is the difference between a tax credit note and a financial credit note?
A tax credit note issued under Section 34 reduces the supplier’s taxable value and output tax, and requires the recipient to reverse proportionate credit. A financial or commercial credit note is a pure commercial adjustment: output tax stays, and per Circular 251/08/2025 the recipient is not required to reverse credit. Choose the type when you design the scheme.
How is value determined when goods are supplied to a branch in another state?
Two registrations of the same entity are distinct persons under Section 25, so transaction value does not apply. Rule 28 requires open market value first, then value of like kind and quality, then Rules 30 or 31. Where the recipient is eligible for full input tax credit, the value declared in the invoice is deemed to be open market value.
Did the September 2025 rate changes alter how value of supply is calculated?
No. The 56th GST Council meeting of 3 September 2025 rationalised rates into 5 per cent, 18 per cent and a 40 per cent demerit slab from 22 September 2025, and removed compensation cess for most categories. Section 15 and Rules 27 to 35 were untouched. Only the rate applied to the value changed, not the way the value is built.
Is TCS collected under the Income-tax Act part of the value of supply?
No. Tax collected at source under the Income-tax Act is not a tax on goods but an interim levy on income, so it does not fall within Section 15(2)(a). If an invoice shows ₹10,000 plus ₹100 TCS, the GST taxable value remains ₹10,000. This differs from a state cess or duty charged separately, which does form part of value.
What happens if I under-declare the value of supply?
The shortfall is recovered with interest under Section 50 and penalty, and the department can raise a demand for past periods. Because valuation errors repeat on every invoice, exposure scales quickly: a ₹432 understatement across 400 invoices is ₹1,72,800 before interest. Review the classification of freight, packing and interest first, since those account for most findings.
The short version
Value of supply is the price plus the law’s additions, minus only two discount routes. Section 15(1) accepts your invoice price only if the parties are unrelated and price is the sole consideration. Section 15(2) then compels you to add non-GST levies, buyer-paid supplier costs, freight, packing, insurance, delay interest and price-linked private subsidies. Section 15(3) removes invoice discounts freely and post-supply discounts only on three strict conditions still in force in August 2026. When the price test fails, Rules 27 to 35 run in fixed order, ending at 110 per cent of cost or a residual method. Get the base right and the rate takes care of itself.
