Rule 35: Backing Tax Out of a Tax-Inclusive Price

Rule 35 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.

Rule 35 is two lines long and is probably the most-used rule in Chapter IV. Retailers use it on every MRP sale. Contractors use it on every inclusive quote. And it is the provision that decides how much a demand is worth when an officer finds unaccounted receipts.

Where the value of a supply is inclusive of integrated tax, or central tax, State tax, Union territory tax and cess, the tax amount shall be determined as: Tax amount = (Value inclusive of taxes × tax rate in percentage of IGST, or CGST, SGST or UTGST and cess) ÷ (100 + sum of tax rates as applicable, in percentage) The taxable value is the inclusive amount less that tax.

The formula, worked

Inclusive amount ₹11,800, rate 18%.

Tax = 11,800 × 18 ÷ 118 = ₹1,800 Taxable value = 11,800 − 1,800 = ₹10,000 CGST ₹900, SGST ₹900.

Inclusive amount ₹10,500, rate 5%.

Tax = 10,500 × 5 ÷ 105 = ₹500 Taxable value = ₹10,000

Inclusive amount ₹14,000, rate 40%.

Tax = 14,000 × 40 ÷ 140 = ₹4,000 Taxable value = ₹10,000

Inclusive amount ₹11,800, IGST 18%. Same arithmetic — the formula uses the sum of the applicable rates, so 9% + 9% and 18% give the same result.

Where it applies

Retail sale at MRP. The printed price includes GST. Every B2C invoice generated from an MRP is a Rule 35 computation, whether or not anyone calls it that.

Contracts quoted inclusive of tax. "₹50 lakh inclusive of all taxes". The taxable value is derived, not stated — which is why a rate change moves the supplier's realisation rather than the customer's outflow. Who keeps the rate cut? →

Government tenders on an inclusive basis. Common in works contracts and services procurement.

Restaurant and hospitality menus priced inclusive.

Demands raised on gross receipts. This is the one that matters most in litigation. Where an officer finds unaccounted receipts and proposes a demand, the receipts are consideration received, and Rule 35 requires the tax to be extracted from them, not added to them.

The demand case, in numbers

An officer identifies unaccounted receipts of ₹1,00,00,000 and proposes tax at 18%.

Adding tax on top: 1,00,00,000 × 18% = ₹18,00,000.

Extracting under Rule 35: 1,00,00,000 × 18 ÷ 118 = ₹15,25,424.

A difference of ₹2,74,576 on the tax alone, before interest and penalty compute on the higher base.

The principle behind Rule 35 is the same one that produced the "cum-duty" line of authority under central excise and service tax, culminating in the settled position that where the assessee has not collected tax separately, the amount received must be treated as inclusive of tax. Rule 35 puts that on a statutory footing.

The argument is available whenever:

• the supplier did not collect tax separately; and
• the amount received is the whole consideration for the supply.

It is not available where the supplier did charge tax separately and simply failed to pay it — there, s.76 applies to the amount collected. Collecting tax you should not have →

Practical notes

• Say which basis you are quoting. "Plus GST" and "inclusive of GST" are different prices. Silence is resolved against the drafter.
• Rule 35 includes cess in the denominator. Where a cess applies, the sum of all applicable rates goes into "100 + sum of tax rates".
• The invoice must still show the value and tax separately. Rule 46 requires the taxable value and the amount of tax to be shown as distinct particulars, even where the agreed price was inclusive.
• Rounding. Section 170 requires the tax to be rounded off to the nearest rupee.
• Raise Rule 35 early in a demand proceeding. It is a computation point, and it is easier to establish at the show cause reply stage than at appeal.

Key takeaways

• Tax = inclusive amount × rate ÷ (100 + rate).
• Used for MRP sales, inclusive contracts, tenders and demands on gross receipts.
• Where tax was not collected separately, receipts must be treated as inclusive.
• The difference against adding tax on top is material — 18% becomes 15.25% of the gross.
• Cess is included in the denominator where it applies.
• The invoice must still show value and tax separately under Rule 46.

Read next

• Rule 34: Which Exchange Rate Applies
• Who Keeps the Rate Cut? GST 2.0 and Your Contracts
• Collecting Tax You Should Not Have: Sections 32 and 76
• Valuation Rules 27 to 35 Explained

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