Section 111 of the Patents Act, 1970
Restriction on power of court to grant damages or account of profits for infringement
Bars damages or an account of profits in defined situations, including innocent infringement, lapsed renewal periods and post-publication amendments.
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.
Nothing here replaces the statute. The official wording of the provision, together with any Gazette notification that applies to it, governs. This page only explains that material in ordinary language.
What this section says, in plain language
Winning on infringement does not always mean winning money. Section 111 lists situations in which the court cannot award damages or an account of profits even though infringement is established. The injunction remains available; it is only the financial remedy that is restricted.
The first situation is innocent infringement. A defendant who proves that at the date of the infringement it was not aware, and had no reasonable grounds for believing, that the patent existed is not liable in damages or to an account of profits. The burden of proof is on the defendant, and it is not easy to discharge in a market where the patentee is known and the technology is well publicised. The section also removes an easy shortcut for patentees: marking a product with the word 'patent' or 'patented' alone does not amount to notice, because it does not tell anyone which patent is meant. Marking with the actual patent number does convey notice, which is why sensible patentees mark products, packaging, catalogues and websites with the number.
The second situation concerns lapsed renewals. Where the renewal fee was not paid within the period allowed and the period was later extended, no damages or account of profits can be granted for infringement committed after the failure to pay and before the extension. The reasoning is fair: while the patent appeared to have lapsed, the public was entitled to treat the technology as free. This point works together with Section 62, which protects those who acted during the lapse before a patent was restored.
The third situation concerns amendments. Where an amendment of the specification, by way of disclaimer, correction or explanation, has been allowed after publication, no damages or account of profits can be granted for use of the invention before the date of the decision allowing the amendment, unless the court is satisfied that the specification as originally published was framed in good faith and with reasonable skill and knowledge. This encourages careful drafting and honest prosecution, and it is why casual over-claiming carries a long-term price.
For a patentee the message is operational rather than legal. Mark products with the patent number, diarise renewal fees so that no lapse occurs, and draft claims that you can stand behind so that no rescue amendment is needed later. For a defendant the message is to check the renewal history and the amendment history of the patent as early as the pleadings stage, because either may remove the money claim entirely.
Why this section matters
Patentees and exclusive licensees claiming money relief, and defendants looking to reduce exposure in an infringement suit.
At the stage of assessing damages or an account of profits, and earlier when pleadings and evidence are prepared.
A statutory bar on financial remedies in the three defined situations, while leaving the court's power to injunct untouched.
A patentee that does not mark products with the patent number, or that allows a renewal to lapse, may recover nothing in money even after proving infringement.
How it works in practice
An unmarked product and a missed renewal
Ananya Rao holds an Indian patent on a clamp used in solar panel mounting. She sells through a single distributor and never marks the product or its packaging with the patent number, and her catalogue says only that the design is patented. Vindhya Structures Pvt Ltd, a Nagpur fabricator, begins making a similar clamp for a rooftop project after copying a sample bought in the open market. Ananya also misses a renewal fee due date and pays it only after obtaining an extension. When she sues, the court finds infringement and grants an injunction. On money, however, Vindhya proves that it had no knowledge of the patent and no reasonable grounds to believe it existed, and points out that the word patented alone in the catalogue is not notice because it gives no number. For the period between the missed renewal and the extension, damages are barred in any event. Ananya obtains her injunction but very little money. Had she printed the patent number on the clamp and on the packaging, and kept the renewal calendar, the outcome on damages would have been quite different.
Simplified illustration only. Actual legal outcomes depend on the facts.
Key points to remember
- Damages and an account of profits are barred where the defendant proves it did not know and had no reasonable grounds to believe the patent existed.
- Marking goods with only the words patent or patented, without the number, is not notice of the patent.
- Marking with the patent number is the simplest way to defeat an innocence defence.
- No money relief for infringement committed after a renewal fee was missed and before the period was extended.
- No money relief for use before an amendment was allowed after publication, unless the original specification was framed in good faith and with reasonable skill and knowledge.
- None of these restrictions affects the court's power to grant an injunction.
Common mistakes and misunderstandings
- Believing that a granted patent automatically gives everyone notice. The Register is public, but the section still allows a genuine innocence defence.
- Marking products with the word patented and nothing else, then relying on it as notice.
- Overlooking the gap created by a missed renewal. The lapse period is a money-free zone for infringement claims.
- Assuming an amendment cures everything. An amendment allowed after publication can cut off damages for the earlier period.
Connected provisions
- ActSection 108Reliefs in suits for infringement
- ActSection 60Applications for restoration of lapsed patents
- ActSection 62Rights of patentees of lapsed patents which have been restored
- ActSection 57Amendment of application and specification before Controller
- ActSection 59Supplementary provisions as to amendment of application or specification
- ActSection 53Term of patent
You will find the related rules grouped below rather than inside the explanation. The separation is deliberate. The Act and the Rules are distinct legal instruments, and mixing them can lead a reader to attribute a procedural requirement to the statute itself.
Forms, deadlines and fees
- No damages or account of profits can be claimed for infringement occurring after a renewal fee was not paid within the allowed period and before that period was extended; the exact renewal periods must be checked against the current Rules.
Open the deadline calculator — and have every date confirmed against the current Rules before you rely on it.
Where a fee is payable under this provision, the figure comes from the First Schedule. Categories of applicant are charged at different rates, and electronic filing is treated differently from paper filing, so an accurate number can only come from the Schedule in force on the day you file. How Indian patent fees work.
Related judgments
Case summaries are published only after a qualified reviewer has checked the judgment, the citation and the way the holding is described. Nothing has cleared that review for this provision yet, so nothing is listed here. We would rather show no case note than one that misstates what a court decided. How case notes are prepared.
Questions people ask about Section 111
Can an infringer avoid paying damages by saying it did not know about the patent?
It can, if it proves the point. Section 111 bars damages and an account of profits where the defendant establishes that at the date of the infringement it was not aware, and had no reasonable grounds for believing, that the patent existed. The burden lies on the defendant. Evidence such as a warning letter you sent, the patent number printed on your product, trade press coverage or the defendant's own internal documents will usually defeat the defence.
Do I have to mark my product with the patent number?
It is not compulsory, but it is one of the most cost-effective things a patentee can do. Section 111 expressly says that marking with the word patent or patented alone, without the number, is not notice of the existence of the patent. Marking with the number removes the innocence defence for anyone who has seen the product. Put the number on the product itself where possible, and also on packaging, manuals, catalogues, quotations and the product page of your website.
What happens to damages if my renewal fee was paid late?
Damages and an account of profits cannot be granted for infringement committed after the failure to pay the renewal fee within the allowed period and before that period was extended. During that gap the patent appeared lapsed to the public, so the law does not make third parties pay for what they did then. Section 62 gives similar protection where a lapsed patent is later restored. Check the current Rules for the exact renewal and extension periods, and diarise them.
Does an amendment to my specification affect what I can recover?
It can. Where an amendment by way of disclaimer, correction or explanation is allowed after the specification has been published, no damages or account of profits are granted for use of the invention before the date of the decision allowing the amendment, unless the court is satisfied that the specification as originally published was framed in good faith and with reasonable skill and knowledge. So an amendment made to rescue an over-broad or careless claim can silently destroy years of potential damages.
Could a technicality wipe out your damages claim?
MYCrave audits patent marking, renewal records and amendment history so that money relief is not lost before the case begins.
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