Patent law is usually defended as a bargain. The inventor discloses the invention, the public receives technical knowledge, and the State grants a temporary monopoly. The formulation is elegant, but it conceals a difficult question. What if another person had already invented the same subject matter, had already used it commercially, but had kept it confidential before the patentee filed the application?
This is the secret first inventor problem. It is not an academic abstraction. It arises in chemical processes, engineering methods, pharmaceutical intermediates, machine tools, software architecture, manufacturing workflows and industrial know-how. Many businesses innovate silently. They do not immediately file patents. They refine methods on factory floors, guard them through confidentiality, and build commercial value through use. If a later applicant secures a patent over the same invention, should the earlier independent user be treated as an infringer?
Several mature patent systems answer that question with restraint. India does not.
In the United States, the direct statutory answer lies in 35 U.S.C. § 273, which recognises a defence to infringement based on prior commercial use. The defence does not invalidate the patent. It protects only the person who can prove, by clear and convincing evidence, that the subject matter had been commercially used before the relevant statutory date. The defence is personal, cannot be freely licensed or assigned, is unavailable where the invention was derived from the patentee, and does not operate as a general licence under all claims of the patent. Its greatest merit is that it does not convert the prior user into a patent destroyer. The patent remains enforceable against the world, but not against the genuine earlier commercial user.
American law also recognises that trade secret protection and patent policy are not mortal enemies. In Kewanee Oil Co. v. Bicron Corp., 416 U.S. 470 (1974), the United States Supreme Court held that Ohio trade secret law was not pre-empted by federal patent law. Kewanee was not a prior user rights case. Its relevance is narrower, but important. It recognised that trade secret protection can coexist with federal patent policy and that protecting confidential know how does not necessarily disturb the patent system’s objective of encouraging invention and disclosure.
The United Kingdom adopts a more direct balance through Section 64 of the Patents Act 1977. A person who, before the priority date, did in good faith an act which would have infringed the patent if the patent had then been in force, or made effective and serious preparations to do such an act, has the right to continue that act notwithstanding the grant of the patent. The right does not extend to granting a licence to another person, and where the act was done or the preparations were made in the course of a business, the transfer of that right is tied to that business.
The leading English authority, Lubrizol Corporation v. Esso Petroleum Co. Ltd., [1998] RPC 727 (CA), gives this defence its necessary discipline. The Court of Appeal did not treat prior use as a passport for unrestricted expansion. At the same time, it did not reduce the defence to a sterile protection of only the identical physical act done before the priority date. The principle is one of genuine continuity. The earlier user is protected because he was already in substance doing the protected act, or had made serious and effective preparations to do it, not because he may later roam freely across the patent monopoly. The UK Intellectual Property Office Manual cites Lubrizol for precisely this understanding of Section 64.
Europe, through Article 28 of the Unified Patent Court Agreement, also preserves rights based on prior use or personal possession by reference to the national law of the relevant Contracting Member State. Even a centralised patent enforcement architecture does not assume that the later patentee must always prevail against the earlier confidential user.
India’s position is more severe. Section 48 of the Patents Act, 1970 confers upon the patentee the exclusive right to prevent unauthorised making, using, offering for sale, selling or importing of the patented product, and similar control over the use of a patented process. Section 107 allows every ground on which a patent may be revoked under Section 64 to be raised as a defence in an infringement suit. Section 64 includes several validity attacks, including want of novelty, obviousness, prior publication, prior public knowledge or public use, insufficiency and secret use in India before the priority date, subject to statutory qualifications.
But this architecture gives the earlier user a sword against validity, not a personal shield against infringement. The prior user must generally attempt to defeat the patent, or resist enforcement through revocation grounds. There is no broad Indian equivalent of a statutory right to say: the patent may remain valid against the world, but I should not be injuncted from continuing what I had independently and commercially done before the patentee filed.
Indian case law reflects this structure. Biswanath Prasad Radhey Shyam v. Hindustan Metal Industries, AIR 1982 SC 1444, remains a leading Supreme Court authority on novelty and inventive step. The Supreme Court explained that the object of patent law is to encourage scientific research, new technology and industrial progress, and that the price of monopoly is disclosure. It also scrutinised the alleged invention for novelty and inventive step, ultimately rejecting the idea that a mere workshop variation could sustain a patent. Biswanath Prasad is therefore important for Indian patent validity jurisprudence, but it does not create or recognise a personal prior user defence.
The contrast with Indian trademark law is striking. Under Section 34 of the Trade Marks Act, 1999, a prior user may prevail even against a registered proprietor. Indian trademark law understands chronology, honest adoption, business continuity and commercial equity. Registration does not obliterate earlier goodwill. Yet in patent law, where the investment may involve years of technical labour, process optimisation and confidential industrial learning, the earlier user receives no comparable statutory sanctuary.
The usual answer is that patent law rewards disclosure, whereas the secret user chose silence. That answer is forceful, but incomplete. A prior user defence does not reward secrecy over disclosure. It merely prevents later disclosure from operating as retrospective confiscation. The patentee still enjoys monopoly rights against the rest of the market. The public still receives the patent specification. The only protected person is the one who can prove independent, good faith, prior commercial use.
This distinction matters profoundly for India. A manufacturing economy cannot assume that all innovation announces itself through patent filings. Much of it arises quietly in workshops, factories, laboratories and code repositories. Some innovators lack resources. Some lack advice. Some deliberately choose confidentiality because disclosure would destroy commercial advantage. To treat all such actors as future infringers is doctrinally harsh and commercially naive.
India does not need weaker patents. It needs more intelligent patents. A narrow prior user defence could require independent development, good faith, commercial use or serious effective preparation in India before the priority date, documentary corroboration, continuity of use, absence of derivation from the patentee, and transfer only with the relevant business. It should not permit licensing to strangers. It should not permit speculative expansion. It should protect continuation, not piracy.
The reform is modest, but the principle is profound. Patent law should distinguish between the later copier and the earlier inventor. It should distinguish between exploitation after reading the patent and exploitation born before the patent existed. It should not compel every prior user to destroy a patent when a limited personal immunity would do justice.
A prior user defence is not anti-patent. It is a fairness correction within patent law. Innovation does not always walk first into the Patent Office. Sometimes it works silently in a factory, a laboratory, a server room or a workshop. The law should not punish that silence when it was honest, independent and commercially real.
About the author: Sidhartha Das is a Partner at Vera Lex.
Disclaimer: The opinions expressed in this article are those of the author(s). The opinions presented do not necessarily reflect the views of Bar & Bench.
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