Someone Copied Your Patented Invention or Registered Design, or You Have Been Sued Over One

What a patent or design case in the Delhi High Court actually decides

A patent case asks two questions: does the defendant's product or process fall within the words of at least one claim of the patent, and is the patent valid. A design case asks whether the defendant's article applies your registered design, or a fraudulent or obvious imitation of it, and whether the registration can survive a challenge that the design was not new. Almost every patent or design suit turns into a fight on both questions, because the defendant's first move is usually to say that the right should be cancelled.

The Delhi High Court hears these disputes through its Intellectual Property Division, set up after the Intellectual Property Appellate Board was abolished in 2021 and governed by the Delhi High Court Intellectual Property Rights Division Rules 2022. Patent suits also follow the High Court of Delhi Rules Governing Patent Suits 2022, which deal with claim charts, confidentiality clubs, technical experts and the order in which evidence is taken. Our guide on the Intellectual Property Division of the Delhi High Court explains how that Division lists and hears cases.

This page covers infringement suits and revocation or cancellation proceedings. If your problem is a refusal or an opposition order from the Patent Office or the Design Office, the route is an appeal, explained on our page on appeals against Trade Marks Registry and Patent Office orders.

The provisions that decide patent and design disputes

Suing for patent infringement: what the owner has to show

The case is built on the claims, not on the title or the drawings. Each claim is broken into its elements, and the defendant's product or process is mapped against every element in a claim chart. If one essential element is missing, there is no literal infringement, although Indian courts also look at whether the defendant has taken the substance of the invention with only trivial changes. When Advocate B.K. Singh is shown a new patent dispute, the first thing he asks for is the granted claims as they stand today, since claims are often amended during examination and the published application can mislead.

For an interim injunction, the owner has to show a strong prima facie case, that the balance of convenience favours an order, and that money will not repair the harm. In patent cases the court also asks whether the defendant has raised a credible challenge to validity. The Division Bench decision in F. Hoffmann-La Roche v. Cipla (2009) is still cited for that test and for the weight given to public interest, especially for medicines. A patent that has survived oppositions, or has been worked for years without challenge, stands on firmer ground at the interim stage.

The court does not always choose between a full injunction and nothing. It may let the defendant continue on terms, such as keeping accounts or depositing money in court, and in standard essential patent cases it has directed pro tem deposits while the case continues.

Damages in Indian patent cases used to be modest, but the Delhi High Court has in recent years awarded large sums after trial, including in telecom patent cases. Damages are proved with evidence of sales, prices, licence rates and lost profits, so the owner's own accounts need to be in order from the start.

Defending a patent suit: the answers that usually matter

A defendant has three main lines. The first is non-infringement: the product does not contain every element of any claim, or works on a different principle. The second is invalidity under Section 107, using any ground available for revocation under Section 64, typically prior art showing the invention was already known or obvious. The third is a statutory exception, such as Section 107A, which protects use of a patented invention for developing information required by law (the regulatory or Bolar exception), and parallel imports from a person authorised to sell.

If the defendant wants the patent struck off the register rather than merely defended against, it files a counter-claim for revocation. In a suit filed in a district court, that counter-claim sends the whole case to the High Court under the proviso to Section 104. A defendant who is sued in a district commercial court in Delhi and has a serious invalidity case should consider this early, because the forum changes.

Section 111 limits damages against an infringer who proves that, on the date of infringement, he was not aware and had no reasonable ground to believe that the patent existed. Marking the product with the word patented and the patent number defeats that defence.

A business that is merely threatened, and not sued, has options too. It can seek a declaration of non-infringement under Section 105 after first asking the patentee in writing for an acknowledgment, or it can sue for groundless threats under Section 106 where letters to its customers are hurting trade without a real basis.

Revoking a patent: post-grant opposition, revocation petition or counter-claim

There are three ways to attack a granted patent. Within one year of publication of the grant, any person interested can file a post-grant opposition before the Controller under Section 25(2). It is cheaper than litigation and decided by an Opposition Board and the Controller, with an appeal to the High Court from the Controller's order.

After that year, or alongside it, a person interested can file a revocation petition under Section 64 directly in the High Court. Before 2021 these went to the IPAB; now they are filed on the original side and heard by the IP Division in Delhi. A person interested includes a manufacturer or trader whose business is affected by the patent, a research body working in the same field, or a company planning to launch a competing product.

The third way is a counter-claim in an infringement suit. The usual grounds across all three are lack of novelty, lack of inventive step, insufficient or unclear description, false suggestion in obtaining the patent, failure to disclose foreign applications under Section 8, and the subject matter being excluded under Section 3, for example a new form of a known substance without enhanced efficacy under Section 3(d).

Which High Court hears a revocation petition can be a live question. The Delhi High Court has drawn a distinction between appeals, which follow the Patent Office branch where the application was filed, and original revocation petitions, where it has accepted filing where the petitioner faces the effect of the patent or where a related suit is pending. The position has been debated, so it should be checked before filing.

Design piracy: copies of your product's shape or pattern

Design protection covers how a product looks, not how it works. A distinctive cooler body, a moulded chair, a printed fabric pattern, a bottle shape or a light fitting can all be registered designs. The test for piracy is visual: would an ordinary buyer, comparing the articles by eye, see the defendant's product as the registered design or an obvious or fraudulent imitation of it. Small differences in detail do not save a copy if the overall look is taken.

Two practical points often decide design cases. The registration must be in force, which means the 10-year term and any 5-year extension have not run out and the renewal was paid on time. And the design must have been new when filed: if the owner sold the product, posted it on a website or showed it at a trade fair before filing, the registration is open to cancellation. Many design suits are lost on the owner's own catalogue.

A registered design can be enforced together with passing off where the product shape has also become a mark of the owner's goods. A larger bench of the Delhi High Court held in Carlsberg Breweries v. Som Distilleries (2018) that both claims can be joined in one suit, which saves cost and avoids conflicting findings. A shape that is purely functional cannot be protected as a design at all; for that, the owner needs a patent.

The statutory sum under Section 22(2) is small, so most owners sue for an injunction and damages. The real value of a design suit is the injunction, often with an order appointing a local commissioner to visit the defendant's premises and seize or inventory the copied goods.

Cancelling a registered design

A design registration that blocks your product can be challenged by a cancellation petition before the Controller of Designs under Section 19. The grounds are that the design was already registered in India, was published in India or elsewhere before the registration date, is not new or original, is not registrable under the Act, or is not a design at all within Section 2(d). An appeal lies from the Controller's order to the High Court, and the Controller may also refer the petition to the High Court.

If you are being sued for piracy, you do not need a separate petition. You can raise every ground of cancellation as a defence under Section 22(4), and the suit is then transferred to the High Court for decision. Evidence of prior publication is the usual weapon: dated catalogues, archived web pages, invoices, foreign registrations and trade fair brochures. Gather them early, with proof of the date, because an undated photograph is worth little.

Which court hears your case, and why

Patent and design infringement suits are commercial disputes under the Commercial Courts Act 2015. In Delhi, a commercial suit valued above Rs 2 crore is filed on the original side of the High Court and goes to the IP Division; smaller suits go to the district commercial courts, which in Delhi sit at the district court complexes such as Saket, Patiala House, Tis Hazari, Rohini, Karkardooma, Dwarka and Rouse Avenue. The Rs 2 crore figure is the limit at present; a proposal to raise it is pending, so check the current limit before valuing the suit. The valuation must be honest and supported, not inflated to get into the High Court.

Whatever the value, a counter-claim for revocation of a patent, or a defence of cancellation of a design, sends the suit to the High Court. Revocation petitions under Section 64 are filed in the High Court directly. Appeals from the Controller of Patents follow the Patent Office branch where the application was first filed, and the Delhi branch covers Delhi and much of north India.

Territorial jurisdiction for a suit depends on where the defendant lives or works, or where the cause of action arose under Section 20 of the Code of Civil Procedure. Sale of infringing products in Delhi, including through a website that targets buyers in Delhi, usually gives the Delhi courts jurisdiction. Unlike trade mark and copyright law, the Patents Act has no special provision letting the owner sue where the owner itself carries on business.

Before filing a commercial suit, Section 12A requires pre-institution mediation unless the suit seeks urgent interim relief. Most patent and design suits against an ongoing copy do seek urgent relief, but the plaint has to show genuine urgency, not a label. A judgment of a single judge of the IP Division is appealed under Section 13 of the Commercial Courts Act to a Division Bench, explained on our page on commercial appeals in the Delhi High Court.

How a patent or design suit moves in the Delhi High Court

The stages below describe a typical suit on the original side. Many cases settle at some point, and an urgent case compresses the first three steps into a few days.

1. Check the right and the product

   Pull the patent or design file, the granted claims, renewal status and any oppositions. Buy the infringing product with a bill and keep it sealed; for a process, gather technical literature or test reports. Prepare a claim chart or a side-by-side design comparison.

2. Decide on notice, mediation or urgent filing

   A cease and desist notice can produce a settlement, but it also warns the copier to clear stock or file a pre-emptive case. Where urgency is real, the suit is filed without notice and Section 12A mediation is skipped; otherwise mediation is attempted first.

3. File the suit with full documents

   The plaint is filed through e-filing with the patent or design certificate, claim charts, test reports, samples, a statement of truth, and the documents the plaintiff relies on. In commercial suits, documents not filed with the plaint can be shut out later, so the file must be complete.

4. First hearing and interim orders

   The judge may grant an ex parte ad interim injunction, appoint a local commissioner to visit premises, or issue notice and hear both sides on interim relief. A defendant who appears may offer to keep accounts or deposit money instead of stopping sales.

5. Written statement, counter-claim and replication

   The defendant must file its written statement within 30 days, extendable up to 120 days at most in commercial suits, and that limit is strict. The counter-claim for revocation is filed with it, followed by the plaintiff's replication and written statement to the counter-claim.

6. Admission and denial, case management

   Before the Joint Registrar, each side admits or denies the other's documents. The judge then frames issues, may constitute a confidentiality club for sensitive technical or sales data, and may appoint a scientific adviser or allow experts to give evidence together.

7. Evidence and final hearing

   Evidence is given by affidavit, followed by cross-examination before the court or a local commissioner. After final arguments, the court decides infringement, validity and damages or account of profits.

8. Appeal and enforcement

   An appeal against the judgment or an interim order lies to the Division Bench under Section 13 of the Commercial Courts Act within 60 days. A decree for damages is enforced by execution like any money decree.

Our guide on how patent infringement suits work in the Delhi High Court walks through these stages in simpler language, and the page on commercial suits above Rs 2 crore covers the general procedure on the commercial side.

Typical time and court fee at each stage

Our professional fees are discussed at the first meeting and agreed in writing, stage by stage. A design piracy suit against a small trader who does not contest costs far less than a pharmaceutical or telecom patent suit with competing experts.

Documents to gather before the first meeting

If you have just been served with a patent or design suit

Note the date of service at once. In commercial suits the written statement must come within 30 days, and the court can extend that only up to 120 days; after that the defence is lost, as the Supreme Court confirmed in SCG Contracts India v. K.S. Chamankar Infrastructure (2019). An ex parte injunction may already be in place, in which case you can apply to vacate it on the ground that facts were suppressed or that the patent is open to a credible challenge.

Do not keep selling in breach of an injunction while you prepare a reply. Contempt and costs follow quickly. If you need to keep trading, consider an immediate offer to keep accounts or deposit a sum, or a design-around that clearly avoids the claims, documented with dates.

Advocate B.K. Singh's practice in defence cases is to run the prior art search and the non-infringement analysis in parallel from the first week, because the interim hearing often comes before the written statement is due, and a defendant who has nothing on validity by then usually loses the interim round.

Mistakes that lose patent and design cases

• Suing on the published application. Rights are enforced on the granted claims. Claims are often narrowed during examination, and a case drafted on the wrong version falls apart at the first hearing.
• Letting renewals lapse. A patent or design that lapsed for non-payment cannot be enforced for the gap, and restoration is not automatic.
• Publishing a design before filing. A product shown on a website, at a trade fair or in a catalogue before the design application can make the registration invalid.
• Waiting too long. A year or two of silence after learning of the copy weakens any request for urgent relief and invites the argument that damages are enough.
• Incomplete documents with the plaint. Commercial court rules can shut out documents that were in your possession but not filed. Gather everything before filing.
• Ignoring the 120 days. Defendants who miss the outer limit for a written statement lose the right to file one, whatever the merits.
• Treating a function as a design. A shape dictated by how a part works is not protected as a design. That calls for a patent or, sometimes, nothing at all.

Startups, MSMEs, foreign owners and NRI inventors: what changes

A small company holding one patent has to be realistic about cost. A full patent trial with experts is expensive, so the strategy is often to secure an interim order and push for settlement or a licence.

Foreign patent owners and NRI inventors can run a Delhi case without travelling. Pleadings are signed under a power of attorney, documents executed abroad are notarised and apostilled or legalised, and evidence can be recorded by video in suitable cases. Two points need early attention: the patentee's compliance with Section 8 (disclosure of foreign applications), which defendants routinely attack, and the working statements under Section 146 on Form 27, which defendants also examine. Our page for NRI and overseas clients in the Delhi High Court covers signatures, apostille and online hearings.

For a manufacturer who is the defendant, the commercial question often matters more than the legal one. If the product line is small, a quick design change and an undertaking may cost far less than three years of defence. If the line is the business, a full invalidity attack and counter-claim are worth the investment.

Settlement, licences and when not to sue

Many patent and design cases end in a licence, a royalty, a phased exit from the market, or a buy-back of stock. The Delhi High Court refers suitable matters to its Mediation and Conciliation Centre, and a settlement there can be recorded and decreed. Where a suit settles, part of the court fee may be refundable under the law on settlement, which is worth checking.

Sometimes the honest advice is not to litigate. A patent with a weak inventive step against well-known prior art can be revoked in the very suit filed to enforce it, leaving the owner worse off. A design that was published before filing will not survive a determined defendant. In those cases a passing off claim, a commercial negotiation, or simply out-competing the copier may be the better course, and the overlap with brand protection is covered on our page on trademark infringement and passing off suits.

What to do this week

Download the current status of the patent or design, confirm renewals, and save the granted claims or representation sheets. Buy one infringing product with a proper bill and keep it unopened. Take dated screenshots of online listings and note the sellers' names. Write down when you first learned of the copy, because the court will ask.

If you are the one served, note the date of service, check whether an interim order has already been passed, and collect your design drawings, first sale invoices and any prior art you know of. Do not reply to the notice or talk to the other side's customers until you have advice, since early admissions are hard to undo.

For advice on your patent or design papers, or for an update on the current jurisdiction position and pecuniary limit, contact Advocate B.K. Singh.