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Economic, Commercial and Intellectual Property Laws · Intellectual Property Rights

Patents Act 1970: Patentability and Procedure

Updated 11 October 2026 · Fact-checked

A patent is an exclusive right granted for an invention that is new, involves an inventive step and is capable of industrial application, and that is not excluded by Section 3. You apply to the Patent Office, the application is published and examined, can be opposed, and if granted lasts 20 years from the filing date.

Understand Patents: Patentability and Procedure

A patent is a right given by the State to an inventor. In return for disclosing the invention fully, the inventor gets a time-limited monopoly. The Patents Act, 1970 governs this in India.

Not everything that is new can be patented. First, the thing must be an invention: a new product or process with an inventive step and industrial application. Second, it must not fall in the list of things that the Act says are not inventions. Section 3 is that list. It is the most tested part of this topic.

Section 3 covers many kinds of subject matter. Examples: frivolous inventions, inventions whose primary or intended use would be contrary to public order or morality, mere discovery of a scientific principle or of a living or non-living substance occurring in nature, methods of agriculture or horticulture, medical treatment processes, plants and animals (other than micro-organisms), mathematical or business methods, computer programmes per se and algorithms, literary and artistic works, presentation of information, topography of integrated circuits, and traditional knowledge.

The procedure runs in stages: filing the application, publication, examination, opposition, and grant. Opposition is possible at two points: before grant (pre-grant) by any person, and after grant (post-grant) within one year of publication of the grant, by any person interested.

Once granted, the term is 20 years from the date of filing. A patent can lapse earlier if renewal fees are not paid. After expiry or cessation, the subject matter gets no protection.

Key rules to remember

Term of patent (Section 53(1))
Term = 20 years from the date of filing of the application
For PCT applications designating India, 20 years from the international filing date.
Lapse for non-payment (Section 53(2))
Renewal fee not paid within the prescribed or extended period → patent ceases to have effect
Under Section 53(4), once the patent ceases or expires, the subject matter gets no protection.
Pre-grant opposition (Section 25(1))
Application published + patent not yet granted → any person may oppose in writing to the Controller
Only on the grounds listed in Section 25(1), and on no other ground.
Post-grant opposition (Section 25(2))
After grant but before one year from publication of grant → any person interested may give notice of opposition
Opposition Board examines and recommends; Controller then orders to maintain, amend or revoke (Section 25(3)-(4)).
Section 3(d) rule
New form of a known substance → not an invention unless there is enhanced known efficacy
Salts, esters, ethers, polymorphs, metabolites, pure form, particle size, isomers, complexes, combinations and other derivatives are treated as the same substance unless they differ significantly in efficacy properties.
Opposition grounds (Section 25)
Wrongful obtaining; prior publication; prior claiming; public knowledge or use in India; obviousness; not an invention or not patentable; insufficient description; non-disclosure under Section 8; convention filing beyond 12 months; source of biological material; traditional knowledge
Eleven grounds, clauses (a) to (k), in both sub-sections.

How to solve Patents: Patentability and Procedure questions

Use this method for any question on patentability or procedure. Write in ICSI style: provision, analysis, conclusion.

  1. 1Identify what is asked: is it patentability (subject matter), procedure (stage), opposition, or term?
  2. 2For patentability, state the test: new, inventive step, industrial application, and not excluded by Section 3.
  3. 3Match the facts to the specific Section 3 clause (for example, 3(k) for a business method or 3(d) for a new form of a known substance). Cite the clause.
  4. 4For procedure, place the facts on the timeline: filing, publication, examination, opposition, grant, renewal.
  5. 5For opposition, check timing first: before grant is Section 25(1), within one year of publication of grant is Section 25(2). Then match the ground.
  6. 6For term, count 20 years from the filing date (or the international filing date for PCT) and check renewal fees.
  7. 7Apply the rule to the facts in two or three sentences.
  8. 8Close with a clear conclusion that answers the question asked.

Quickest way: Three-check shortcut

When to use it: Use it for short-note and case-study questions when time is tight.

  1. Check 1: Is it excluded by Section 3? Scan the list by keywords: discovery, new form, mixture, arrangement of known devices, agriculture, medical treatment, plants and animals, business method, software per se, art, information, traditional knowledge.
  2. Check 2: Which stage is it? Pre-grant opposition, post-grant opposition, or term and renewal.
  3. Check 3: Write the section number, one line of rule, one line of facts, then the conclusion.

Common mistakes in Patents: Patentability and Procedure

  • Saying all computer programmes are non-patentable.

    Students remember Section 3(k) as a blanket bar.

    Fix: The bar is on a computer programme per se, a mathematical or business method, or algorithms. Write the exact words.

  • Treating any new form of a known drug as patentable.

    Novelty is confused with patentability.

    Fix: Under Section 3(d) a new form of a known substance is not an invention unless it enhances known efficacy. Mention the Explanation about salts, polymorphs and so on.

  • Counting the 20-year term from the date of grant.

    Students link the term with the date the right begins.

    Fix: Section 53(1) counts from the date of filing. For PCT applications, from the international filing date.

  • Mixing up who can file pre-grant and post-grant opposition.

    Both are in Section 25 and look alike.

    Fix: Pre-grant: any person, after publication and before grant. Post-grant: any person interested, within one year from publication of grant.

  • Forgetting that plants and animals are excluded but micro-organisms are not.

    Students memorise the exclusion without its exception.

    Fix: Section 3(j) excludes plants and animals in whole or any part, other than micro-organisms, including seeds, varieties, species and essentially biological processes.

  • Ignoring the consequence of lapse.

    Students stop at the 20-year rule.

    Fix: Add Section 53(2) and 53(4): non-payment of renewal fee causes cessation, and the subject matter then gets no protection.

Worked examples

Example 1

Rohan, a Pune software developer, has written an algorithm that sorts delivery routes faster and wants a patent on the algorithm itself. Also, he has designed a new arrangement of three existing devices in a warehouse, each working independently as before. Advise whether either can be patented.

Show the solution
  1. Rule: Section 3 lists things that are not inventions. Section 3(k) excludes a mathematical or business method or a computer programme per se or algorithms.
  2. Application to the algorithm: Rohan claims the algorithm itself. This falls squarely within Section 3(k).
  3. Rule for the arrangement: Section 3(f) excludes the mere arrangement, re-arrangement or duplication of known devices each functioning independently of one another in a known way.
  4. Application: the three devices are known and each functions independently as before, so this is a mere arrangement.

Answer: Neither claim is patentable. The algorithm per se is excluded by Section 3(k) and the arrangement of known independent devices is excluded by Section 3(f).

Example 2

A patent application by Sunrise Pharma Ltd was filed on 10 March 2024 and published. State (a) who may oppose before grant, (b) when post-grant opposition is possible if the patent is granted and the grant is published on 1 September 2026, and (c) when the patent expires if all renewal fees are paid.

Show the solution
  1. Pre-grant: Section 25(1) allows any person to represent by way of opposition in writing to the Controller, after publication and before grant, on the listed grounds only.
  2. Post-grant: Section 25(2) allows any person interested to give notice of opposition after grant but before one year from the date of publication of grant.
  3. Compute: one year from 1 September 2026 ends on 1 September 2027, so notice must be given before that date.
  4. Procedure: the Controller notifies the patentee and constitutes an Opposition Board, which recommends. After hearing both sides, the Controller orders to maintain, amend or revoke the patent (Section 25(3)-(4)).
  5. Term: Section 53(1) gives 20 years from the date of filing. 10 March 2024 plus 20 years gives 10 March 2044. Renewal fees must be paid, otherwise the patent ceases under Section 53(2).

Answer: (a) Any person, before grant, on the Section 25(1) grounds. (b) Any person interested, before 1 September 2027. (c) The patent expires on 10 March 2044, provided renewal fees are paid; after that, the subject matter gets no protection (Section 53(4)).

Exam tips

  • Learn the Section 3 clauses by keyword and clause letter. Examiners often give a fact pattern and expect the right clause.
  • Quote exact conditions: 'per se', 'mere', 'known substance', 'enhancement of known efficacy'.
  • For opposition, always state the timing and who may file before listing grounds.
  • Write the 20-year term from the filing date, and add the lapse rule for renewal fees.
  • Structure each answer as provision, application, conclusion; cite the section.

Practice questions from Intellectual Property Rights

Patents: Patentability and Procedure in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Patents: Patentability and Procedure: frequently asked questions

What is not patentable under Section 3 of the Patents Act?

Section 3 lists things that are not inventions. These include frivolous inventions, mere discovery of scientific principles or natural substances, methods of agriculture, medical treatment processes, plants and animals other than micro-organisms, business methods, computer programmes per se, algorithms, artistic works, presentation of information and traditional knowledge.

How long does a patent last in India?

Twenty years from the date of filing of the application under Section 53(1). For PCT applications designating India, it is twenty years from the international filing date. It can end earlier if renewal fees are not paid.

What is the difference between pre-grant and post-grant opposition?

Pre-grant opposition under Section 25(1) can be made by any person after publication and before grant. Post-grant opposition under Section 25(2) can be made by any person interested within one year of publication of grant, and is examined by an Opposition Board.

Is software patentable in India?

A computer programme per se, a mathematical or business method, and algorithms are not inventions under Section 3(k). So the bar applies to these in themselves, and you should state it in those exact words.