Principal supply in bundled contracts: getting the rate right
Identifying the principal supply is the whole of the composite supply exercise. It is also the part usually asserted rather than reasoned.
Section 2(90) defines the principal supply as the supply of goods or services which constitutes the predominant element of a composite supply, to which any other supply is ancillary. The identification is a question of fact determined by the purpose of the transaction, the commercial substance, the value of the elements and the understanding of the recipient. Value alone is not determinative, although it is the factor most readily available.
The factors, in the order they persuade
The purpose for which the recipient contracted. What did the customer want? The rest is ancillary.
The commercial substance of the transaction, as evidenced by the contract's scope, its title and its acceptance criteria.
The value of the elements, which supports the analysis but does not decide it. A low value element can be the principal supply where it is the object of the contract.
The ability of the elements to be supplied independently. An element that cannot be supplied on its own is usually ancillary.
Industry practice, established by comparable contracts.
The recurring patterns
Equipment with installation and commissioning. The principal supply is usually the equipment, and the rate follows the goods, unless the contract is genuinely for a works contract or for the erection of an immovable structure.
Software with implementation and support. The characterisation of the software supply itself governs, and the implementation is typically ancillary.
Transport with loading, unloading and warehousing. Where the object is the movement of goods, the transport service is principal and the rest ancillary.
Maintenance contracts covering parts and labour. Where the object is the availability of the equipment, the service is principal, and the supply of parts is ancillary.
Turnkey construction contracts, which are works contracts and are analysed under that head rather than as ordinary composite supplies.
Documenting the position
State the principal supply and the reasoning in a note at the contracting stage, referring to the factors, and keep it with the contract.
Align the contract's own language with the position: the title, the scope, the deliverable, the acceptance and the warranty should all describe the same principal object.
Use consistent HSN and rate across similar contracts, and record the reason for any departure.
Where the position is genuinely borderline and the value is material, consider an advance ruling before signing rather than after invoicing.
What to do on Monday
Write the principal supply note at the contracting stage, with the factors applied.
Align the contract title, scope, acceptance and warranty with the position taken.
Keep the rate treatment consistent across similar contracts and record any departure.
Obtain an advance ruling before signing where the position is borderline and the value is material.
This page states the general position. A reader with a specific question on their own facts may write to the GST practice at AMLEGALS.
Write to the GST practiceQuestions we are asked on this
Is the highest value element always the principal supply?
No. Value supports the analysis; the purpose of the transaction decides it.
Can a contract state the principal supply?
It can record the parties' understanding, which is evidence. It cannot determine the legal characterisation.
What if there is no predominant element?
Then the bundle may not be a composite supply at all, and the mixed supply rule with the highest rate becomes the risk.
Does the recipient's use matter?
The purpose for which the recipient contracted matters. What the recipient later does with the supply usually does not.
How is a works contract different?
It is a defined composite supply with its own rate entries, and it is analysed under those entries rather than by identifying a principal supply.
In this cluster
- GST 2.0: two slabs did not end classification litigation, they moved the battle line
- Rate change transition: time of supply, credit notes and stock in hand
- Classification disputes under GST: the principles the courts apply
- Westinghouse Saxby: the sole or principal use test and the end of easy classification
- HSN, common parlance and the General Rules of Interpretation
- Composite supply versus mixed supply: the test, and the tax
- Food, beverages and the restaurant service rate maze
- Textiles and apparel: the rate structure and the disputes it produces
- Pharmaceuticals and medical devices: the concession and its boundaries
- Automobiles and auto components: the rate bands and the component question
GST Insights is published by AMLEGALS for general information. Law stated as on 3 September 2026. Not advice on any particular set of facts; not an advertisement or a solicitation under Rule 36 of the Bar Council of India Rules. Readers with a question on their own facts may write to the GST practice of their own accord.