The most common and expensive mistake inventors make in India is spending months and significant money drafting and filing a patent application — only to have it refused because the invention falls squarely within a statutory exclusion that could have been identified in a fifteen-minute legal review.
India’s patent law does not follow a “you can patent anything novel” principle. The Patents Act, 1970 contains a detailed list of things that are expressly not patentable — regardless of how novel, useful, or commercially valuable they are. Understanding these exclusions before you file is not just useful — it is essential.
This guide explains what can be patented in India, walks through every major exclusion under Section 3 of the Patents Act, 1970, and addresses the most contested areas — software, pharmaceuticals, business methods, and traditional knowledge — where the lines are genuinely unclear.
What Can Be Patented — The Three Core Requirements
Before reaching the exclusions, understand what the positive requirements are.
Under Section 2(1)(j) of the Patents Act, 1970, an invention means a new product or process involving an inventive step and capable of industrial application.
All three elements must be satisfied:
Novelty — the invention must not have been disclosed anywhere in the world — in any publication, patent document, public use, or prior knowledge — before the date of filing. A single journal article, a conference presentation, or even your own prior patent application disclosing the same thing can destroy novelty.
Inventive step — Section 2(1)(ja) defines this as a feature that makes the invention not obvious to a person skilled in the art, and that involves either technical advancement over existing knowledge or has economic significance, or both. It is not enough to modify something in a way that any trained engineer would think of.
Industrial applicability — under Section 2(1)(ac), the invention must be capable of being made or used in any industry. Purely theoretical concepts with no practical application do not qualify.
If your invention satisfies all three — and does not fall within any exclusion under Section 3 — it is patentable.
Section 3 — What Is Expressly Not Patentable
Section 3 of the Patents Act, 1970 is headed “What are not inventions.” It lists 16 clauses — Section 3(a) through Section 3(p) — specifying categories that are not patentable regardless of novelty or inventive step. Here are the most practically significant ones.
Section 3(a) — Frivolous Inventions and Those Contrary to Natural Laws
An invention that is frivolous or claims something obviously contrary to well-established natural laws is not patentable.
Example: A machine that claims to produce energy without any input — a perpetual motion machine — contradicts the law of conservation of energy and is excluded under Section 3(a).
Practical note: This exclusion is rarely a surprise to serious inventors. Most Section 3(a) objections arise where claim language is drafted in a way that implies an impossible result.
Section 3(b) — Inventions Contrary to Public Order or Morality
An invention whose primary or intended use would be contrary to public order or morality, or that causes serious prejudice to human, animal, or plant life, health, or the environment is not patentable.
Examples:
- A device designed primarily for counterfeiting currency
- A process for producing a biological agent intended for use as a weapon
- An invention that causes significant environmental damage with no countervailing benefit
Practical note: This exclusion requires the harm to be a primary or intended use — not a possible misuse. A kitchen knife is not excluded simply because it could be used as a weapon.
Section 3(c) — Mere Discoveries of Scientific Principles and Natural Phenomena
The mere discovery of a scientific principle, the formulation of an abstract theory, or the discovery of any living or non-living thing occurring in nature is not patentable.
Examples:
- The discovery of a new planet or mineral in its natural form
- The identification of a naturally occurring protein or enzyme in its natural state
- A mathematical theorem or abstract scientific principle
The key distinction: Discovery is not the same as invention. Identifying something that already exists in nature — even if no one knew about it before — is not patentable. But applying that discovery to create something new that does not exist in nature — a process, a product, a method — may be patentable.
A naturally occurring microorganism isolated from soil is not patentable. A novel process for cultivating that microorganism to produce a useful compound may be.
Section 3(d) — New Forms of Known Substances Without Enhanced Efficacy
This is one of the most distinctive and internationally debated provisions of Indian patent law.
Under Section 3(d), the following are not patentable:
- The mere discovery of a new form of a known substance that does not result in the enhancement of the known efficacy of that substance
- Salts, esters, ethers, polymorphs, metabolites, pure form, particle size, isomers, mixtures of isomers, complexes, combinations, and other derivatives of a known substance — unless they differ significantly in properties with regard to efficacy
The Novartis case — the landmark decision: The most important case interpreting Section 3(d) is Novartis AG v. Union of India (2013) decided by the Supreme Court of India. Novartis sought a patent for the beta crystalline form of Imatinib Mesylate — a modified form of Imatinib, an anti-cancer drug.
The Supreme Court held that the beta crystalline form was a new form of a known substance — Imatinib — and that Novartis had failed to demonstrate that the new form resulted in enhanced therapeutic efficacy over the known substance. The patent was refused under Section 3(d).
This decision has made India one of the most important jurisdictions globally for pharmaceutical patent law, and Section 3(d) remains a significant filter for pharmaceutical patent applications in India.
What this means in practice:
- A new salt form of an existing drug — not patentable unless proven to be significantly more efficacious
- A new polymorph of a known compound — not patentable unless it demonstrates meaningfully enhanced therapeutic effect
- A genuinely new drug molecule that does not exist in any prior art form — potentially patentable if novel and inventive
Section 3(d) was specifically designed to prevent patent evergreening — the practice of pharmaceutical companies filing successive patents on minor modifications of existing drugs to extend monopoly protection beyond the intended period.
Section 3(e) — Mere Admixtures
A substance obtained by mere mixing that results only in the aggregation of the properties of its components, or a process for producing such a substance, is not patentable.
Example: Simply mixing two known chemicals together to produce a result that is merely the sum of their individual known properties does not constitute an inventive step and is excluded under Section 3(e).
The exception: If the combination produces a synergistic effect — a result that is greater than or different from the sum of the parts — it may overcome the Section 3(e) bar, provided the other patentability criteria are satisfied.
Section 3(f) — Mere Arrangements of Known Devices
The mere arrangement or re-arrangement of known devices, each functioning independently in a known way, is not patentable.
Example: Combining a known torch with a known pen in an obvious way, where both function exactly as they would independently, does not produce a patentable invention.
Section 3(h) — Agricultural and Horticultural Methods
A method of agriculture or horticulture is not patentable.
What is excluded: Traditional cultivation techniques, crop growing methods, and standard agricultural practices.
What may still be patentable: Novel agricultural apparatus or tools, specific technical processes used in agriculture that involve non-obvious technical innovation, and inventions relating to agricultural inputs (fertilisers, pesticides) where the inventive step lies in the chemical composition rather than the agricultural method itself.
Section 3(i) — Methods of Medical Treatment
Any process for the medicinal, surgical, curative, prophylactic, diagnostic, therapeutic, or other treatment of human beings, animals, or plants is not patentable.
What is excluded:
- A surgical technique for a particular operation
- A method of treating a disease using an existing drug
- A diagnostic method for identifying a medical condition
What is not excluded:
- The drug itself — if novel and meeting Section 2(1)(j) and not caught by Section 3(d)
- The medical device or surgical instrument used in the treatment
- A diagnostic kit or apparatus
The exclusion is on the method — not the product used in it.
Section 3(j) — Plants, Animals, and Biological Processes
Plants and animals in whole or any part thereof, other than microorganisms, are not patentable. Seeds, varieties, and species, and essentially biological processes for the production or propagation of plants and animals, are also excluded.
What is excluded:
- A new variety of rice or wheat — even if developed through selective breeding
- A new animal breed
- A process of cross-pollination that is essentially biological
What may be patentable:
- A novel microorganism if it satisfies patentability criteria
- A non-biological or technical process for producing a plant variety
- A technical tool used in plant variety development (a genetic sequencing device, for instance)
Section 3(k) — Mathematical Methods, Business Methods, Computer Programs, and Algorithms
This is the section that affects technology startups, software companies, and fintech businesses most directly.
Under Section 3(k), the following are not patentable:
- A mathematical or business method
- A computer programme per se
- Algorithms
What is clearly excluded:
- A sorting algorithm
- A financial model or trading strategy
- A method of calculating insurance premiums
- Source code stored on a computer-readable medium
The critical qualification — “per se”:
The phrase “computer programme per se” has been interpreted by Indian courts to mean that not all software-related inventions are excluded — only software in isolation.
In Ferid Allani v. Union of India & Ors. (Delhi High Court, 2019), the court held that software inventions that produce a technical effect — particularly when integrated with hardware and producing a result beyond what the software does in isolation — may be patentable.
The Indian Patent Office’s Computer Related Inventions (CRI) Guidelines (most recently updated in 2017) clarify that a claim to a computer programme that, when run, causes a computer to perform specific technical functions may be patentable if it produces a technical advancement.
What this means in practice for startups:
- A claim to a software algorithm alone — not patentable
- A claim to a method implemented by a computer system that produces a specific technical effect, with the hardware playing an integral functional role — potentially patentable
- A claim to a specific hardware-software combination that solves a concrete technical problem in a novel and non-obvious way — most likely patentable
This is genuinely nuanced territory. The same invention can be patentable or non-patentable depending entirely on how the claims are drafted. This is the clearest example of why claim drafting by a specialist is not optional in software-adjacent patent applications.
Section 3(l) — Literary, Dramatic, Musical, and Artistic Works
These are covered by copyright, not patents. A novel, a screenplay, a painting, a musical composition, or a piece of software source code considered as a creative work is excluded from patentability.
Section 3(m) — Mental Acts, Mathematical Methods, and Games
Schemes, rules, or methods for performing mental acts, methods of playing games, or methods of performing purely mental operations are not patentable.
Section 3(p) — Traditional Knowledge
An invention that in effect is traditional knowledge or an aggregation or duplication of known properties of traditionally known components or processes is not patentable.
Example: Claiming a new use for turmeric (haldi) in wound healing — which has been part of Indian traditional medical practice for centuries — is not patentable because it is traditional knowledge, not a new invention.
This provision was introduced following international controversy over patents granted in other jurisdictions (most notably the United States) for uses of Indian traditional medicinal plants and preparations. India’s Traditional Knowledge Digital Library (TKDL) — a database of documented traditional knowledge — is now shared with patent offices worldwide to prevent such patents from being granted.
Section 4 — Atomic Energy
Separately from Section 3, Section 4 of the Patents Act, 1970 bars patents for any invention relating to atomic energy falling within Section 20(1) of the Atomic Energy Act, 1962. This is an absolute bar — no exceptions.
Practical Decision Guide — Is Your Invention Patentable?
Work through these questions before investing in a patent application:
Is it a product or process? If yes — it may be patentable. If it is a pure concept, idea, principle, or discovery, it almost certainly is not.
Is it novel? Has it been disclosed anywhere — in any form — before your intended filing date? If yes — it is not patentable.
Is it inventive? Would a person skilled in the relevant technical field consider it obvious? If yes — it is not patentable.
Does it fall within Section 3? Go through the exclusions above. If it clearly falls within any clause — 3(b), 3(d), 3(i), 3(j), 3(k) — you need professional advice before concluding it is patentable or not.
If it is software-related: The answer depends entirely on claim drafting. Do not assume it is excluded or included without specialist advice.
If it is pharmaceutical: Section 3(d) is the critical filter. Enhanced efficacy must be demonstrable and significant — not marginal.
If it involves traditional Indian knowledge: Section 3(p) is likely to apply.
Frequently Asked Questions
Q: Can a software invention be patented in India?
A: Pure software — a computer programme per se — is excluded under Section 3(k) of the Patents Act, 1970. However, software-implemented inventions that produce a specific technical effect, particularly when the invention involves a hardware-software integration and the claim is not directed at the software in isolation, may be patentable. The Delhi High Court in Ferid Allani v. Union of India (2019) confirmed that software inventions with a technical effect are not automatically excluded. Claim drafting is critical — the same invention can be patentable or not depending on how claims are written.
Q: What did the Novartis case decide about Section 3(d)?
A: In Novartis AG v. Union of India (2013), the Supreme Court of India held that a new form of a known substance — the beta crystalline form of Imatinib Mesylate — was not patentable under Section 3(d) because Novartis failed to demonstrate that the new form had significantly enhanced therapeutic efficacy over the known base compound Imatinib. The judgment confirmed that Section 3(d) is specifically designed to prevent pharmaceutical patent evergreening and that enhanced efficacy must be proven, not merely asserted.
Q: Can a business method be patented in India?
A: No. Business methods are expressly excluded from patentability under Section 3(k) of the Patents Act, 1970. A financial model, a method of conducting business, a trading strategy, or a process for managing operations — even if genuinely novel and commercially valuable — cannot be patented in India.
Q: Can a naturally occurring substance be patented in India?
A: No. The mere discovery of any living or non-living thing occurring in nature is excluded under Section 3(c). A naturally occurring microorganism, protein, enzyme, or mineral in its natural state cannot be patented. However, a novel process for isolating or modifying such a substance, or a product derived from a technical intervention that does not exist in nature in that form, may be patentable if the other criteria are satisfied.
Q: Can traditional Indian medicinal knowledge be patented?
A: No. Under Section 3(p) of the Patents Act, 1970, an invention that in effect is traditional knowledge, or an aggregation or duplication of known properties of traditionally known components, is not patentable. India’s Traditional Knowledge Digital Library (TKDL) documents traditional knowledge and shares it with patent offices globally to prevent such patents from being granted in India or other jurisdictions.
Q: Can a method of surgery be patented in India?
A: No. Methods for the surgical, therapeutic, curative, prophylactic, diagnostic, or other treatment of human beings or animals are excluded under Section 3(i) of the Patents Act, 1970. However, surgical instruments, medical devices, and drug compositions — as products rather than methods — can be patented if they satisfy the general patentability criteria and are not caught by Section 3(d).
A Note from Practice
Section 3 exclusions are not always obvious from the face of an invention. Whether a software-hardware combination qualifies under Section 3(k), whether a pharmaceutical formulation satisfies the enhanced efficacy requirement under Section 3(d), or whether a biological process is “essentially biological” under Section 3(j) — these are legal and technical judgements that require specialist analysis.
The cost of getting this wrong is real. A patent application that is refused after several years of prosecution has wasted both time and money. Worse, if you publicly disclosed the invention before filing in the belief that it was patentable, you may have lost your novelty and your ability to seek protection in other jurisdictions as well.
Before filing any patent application in India, get a patentability opinion from a qualified patent attorney or registered patent agent. It is the most cost-effective step in the entire patent process.
Book a Free IP Consultation → TMZON
For a step-by-step guide to the full patent filing procedure in India:
How to File a Patent in India — Step-by-Step Guide → TMZON
For how patents compare with trademarks and copyright for your business:
Patent vs Trademark vs Copyright in India → TMZON
This article is written for general informational purposes and does not constitute legal advice. For advice specific to the patentability of your invention, please consult a qualified patent attorney or registered patent agent.
© 2026 TMZON Corporate Services. All rights reserved.
