Section 19 of the Patents Act, 1970
Powers of Controller in case of potential infringement
Lets the Controller require a public notice in a specification where working the claimed invention would probably infringe a claim of another live patent.
Official legal text
The verbatim statutory text of this provision is reproduced from the official source and checked by our legal reviewer before it is published here. Until that check is complete for this page, read the exact wording directly from the official source linked below — it is the only version that governs.
This is a simplified explanation. Where it differs from the official text of the provision, or from an applicable Gazette notification, the official text and the notification prevail.
What this section says, in plain language
A patent gives its owner the right to stop others from using what its claims cover. That means two patents can exist side by side and still collide: the second invention may be new and inventive, yet impossible to use in practice without stepping on the first patent's claims. Section 19 is the Act's response to that overlap during examination.
Where it appears to the Controller that the invention claimed in an application cannot be performed without a substantial risk of infringing a claim of another patent, the Controller may direct that a reference to that other patent be inserted in the applicant's complete specification. The reference is described as a notice to the public. Anyone who later reads the granted specification is told, on its face, that another patent stands in the way.
The applicant has answers available. If the applicant can show that the priority date of the relevant claim is not later than the priority date of the other patent's claim, the direction should not be made. The applicant may also amend the complete specification so that the claims no longer run into the other patent. The Rules set out how the matter is raised, how the applicant responds, and the form the printed reference takes.
The reference is not permanent. If the other patent is later revoked or ceases to be in force, or the offending claim in that patent is deleted by amendment, or a competent authority holds that claim invalid or not infringed by the applicant's invention, the Controller may order the reference to be deleted. Importantly, section 19 does not decide infringement. It creates transparency during examination; a real infringement dispute is fought in court under the enforcement provisions.
Why this section matters
Applicants working in crowded fields, especially improvements built on top of an existing patented platform.
During examination, before grant, when the search reveals a live patent standing across the applicant's route to market.
A power in the Controller to order a public cross-reference to another patent, and a later power to remove it.
A granted patent may carry a permanent warning label that reduces its licensing value and alarms investors during due diligence.
How it works in practice
An improvement that could not be used alone
A Coimbatore textile MSME, Sundara Looms, applied for a patent on a yarn tension sensor that improved the output of a particular type of air-jet loom. The sensor itself was new. During examination the Controller noticed that the claims described the sensor only as fitted to a loom whose feed mechanism was covered by a live patent held by another Indian company. Working the sensor as claimed would almost certainly have used that feed mechanism too. The Controller proposed a reference to the other patent in Sundara's specification. The company's agent responded by amending the claims so that they covered the sensor and its mounting on its own, independent of any particular feed mechanism. With the claims redrawn, the direction was not pressed and no reference was printed. Sundara later negotiated a licence with the other patentee anyway, but it did so from a stronger position, with a clean granted specification in hand.
Simplified illustration only. Actual legal outcomes depend on the facts.
Key points to remember
- The trigger is a substantial risk that working the claimed invention would infringe a claim of another patent.
- The remedy is a printed reference to that other patent in the applicant's own complete specification, as a notice to the public.
- Showing that your claim's priority date is not later than the other patent's claim defeats the direction.
- Amending the claims to avoid the overlap is the usual practical answer.
- The reference can later be deleted if the other patent is revoked, lapses, is amended, or the claim is held invalid or not infringed.
- The section does not decide infringement and does not give anyone a licence.
Common mistakes and misunderstandings
- Reading the reference as a finding that you infringe. It is a warning to readers, not an adjudication, and the courts decide infringement.
- Believing your own granted patent guarantees freedom to operate. A patent is a right to exclude others, not a permission to practise over someone else's rights.
- Ignoring the reference once it is printed. If the blocking patent later lapses or is revoked, the Controller can be asked to remove it, and doing so cleans up the record before a licensing negotiation.
Connected provisions
Sections and rules are different kinds of law. A section is enacted by Parliament, while a rule is made by the Central Government using powers the Act grants. Keeping them apart shows which text you are reading and which of the two is more likely to have been revised recently.
Forms, deadlines and fees
- Any response or amendment must be made within the period allowed for putting the application in order for grant under section 21.
Open the deadline calculator — and have every date confirmed against the current Rules before you rely on it.
The official fee for anything described on this page is set out in the First Schedule to the Patents Rules. It is not the same for every applicant, and it is not the same for online and physical filing, which is why no amount is stated here. How Indian patent fees work.
Related judgments
No judgment summaries appear here yet. Our process requires a legal review of each case note before publication, covering the citation, the court and the point actually decided. Until a note for this provision has passed that check, the section stays empty rather than carrying unverified material. How case notes are prepared.
Questions people ask about Section 19
Does a reference under section 19 mean my patent is invalid?
No. Validity and infringement are different questions. A reference says only that working your invention as claimed may run into someone else's live patent. Your claims can still be perfectly valid, new and inventive. What the reference affects is freedom to operate: it publicly signals that you may need a licence from the other patentee before you can commercialise the invention as claimed.
How do I avoid a reference to another patent being printed?
Two routes are open. Show that the priority date of your claim is not later than the priority date of the other patent's claim, which removes the basis for the direction. Or amend your complete specification so the claims no longer require the features covered by the other patent. Amendment is the common answer, and it works best where the specification already describes a standalone version of the invention.
Can the reference be removed later?
Yes. If the other patent is revoked, ceases to be in force, or is amended to delete the relevant claim, or if a competent authority holds that claim invalid or holds that your invention does not infringe it, the Controller may order the reference deleted. This is worth doing before a licensing round or an assignment, because the printed reference is one of the first things a careful buyer notices.
Is section 19 the same as a freedom-to-operate search?
No, though they overlap. A freedom-to-operate search is something you commission yourself, covering live patents in the markets you plan to enter. Section 19 is a power the Controller exercises during examination, limited to what the Office notices. Relying only on the Office is risky, because examination is aimed at patentability, not at clearing your commercial path.
Will your invention run into someone else's patent?
MYCrave Consultancy maps blocking patents and redrafts claims so your grant is not saddled with a public warning.
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