Patent Litigation 2026 Comparisons

Indian law provides for protection of “inventions” under the Patents Act, 1970 (the “Act”).

An “invention”, defined under the Act as a new product or process involving an inventive step and which is capable of industrial application, is protected by way of a patent. Whether an invention is capable of being protected as a patent is based on both the provisions of the Act (particularly Sections 3 and 4, which provide the criteria for exclusion from patentability) and on case law interpreting the scope of the Act’s provisions.

For example, Section 3(d) of the Act stipulates, inter alia, that “the mere discovery of a new form of a known substance” would not qualify as an invention unless it “result(s) in the enhancement of the known efficacy of that substance”. Efficacy in the context of medicines has been held to mean therapeutic efficacy by the Supreme Court of India in Novartis AG v Union of India and Others, 2016 (6) SCC 1.

A patent is a creature of statute and arises only once an application made before the Indian Patent Office is granted as per the Act, duly supplemented by the Patent Rules, 2003.

The grant procedure for a patent typically arises with the filing of an application before the Indian Patent Office. India permits filing of a provisional specification with an ordinary application, and provides the applicant with 12 months to file the complete specification. For a convention application, Section 135 of the Act prescribes that such application be filed within 12 months from the date of first application in a convention country. A Patent Cooperation Treaty (PCT) National Phase application must be filed within 31 months from the priority date of the PCT international application.

The next stage in the grant procedure is the publication of the patent application under Section 11A of the Act. The patent application is published after expiry of 18 months from the date of its filing or priority date, whichever is earlier, to give due notice to the public and to facilitate filing of pre-grant oppositions, if any. However, it is possible for an applicant of a patent application to request an early publication of the patent application by filing such request under Section 11A(2) of the Act.

A patent application made before the Indian Patent Office is not examined automatically upon filing. Under Section 11B of the Act, an applicant is required to furnish a request for examination within 48 months from the date of filing or priority. As per the Patent Amendment Rules, 2024, the timeline for filing such a request for examination has been reduced to 31 months from the filing date, for all applications filed on or after 15 March 2024.

After a request for examination is filed, the Indian Patent Office issues a First Examination Report under Section 12 of the Act, raising formal or substantive objections. The applicant generally has six months to respond and propose amendments, and may be granted an oral hearing if required. If the application is otherwise in order and no pre-grant opposition is pending, it proceeds to grant; where a pre-grant opposition exists, the application is decided only after the opposition is adjudicated.

Timeline

There is no specific timeline in which the grant procedure must be completed. Typically, the timeline for such procedure is around three to five years, and may vary depending on extensions in timelines sought by the applicant in filing responses and ensuring due compliance with mandates by the Indian Patent Office, or on the volume of cases pending adjudication before the Patent Office. Further, the existence of multiple pre-grant oppositions and their adjudication may also delay the process beyond the estimated timeline above.

Representation

An applicant need not necessarily have any legal representation. As provided under Section 6 of the Act, an applicant is free to file a patent application on their own.

Costs

The average costs of granting an ordinary application filed in India entail the statutory fee, payable to the Indian Patent Office, and the professional fee that may be payable to a patent agent (if any) for filing such patent application.

Additionally, conducting a patentability or clearance search before filing – especially if done by a patent agent to assess the likelihood of a grant – can increase overall costs. Applicants may also perform such searches themselves at no cost using the Indian patent database or other publicly available resources, such as Google Patents or Espacenet.

The statutory fee payable to the Indian Patent Office consists of:

• the filing fee;
• the fee accompanying an application seeking extension of time;
• the fee for expedited filing/examination; and
• the fee for filing a request for examination, et al.

This is as prescribed under Schedule I of the Patent Rules, 2003.

Being a signatory to the Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPS), India recognises the term of a granted patent to be 20 years from the date of filing of such patent application; in the case of a National Phase application, the term of the patent will be 20 years from the international filing date.

Section 48 of the Act provides the patentee with exclusive rights to restrain third parties from the act of making, using, offering for sale, selling or importing for those purposes that product in India. In the case of a process patent, the provision also provides a patentee the exclusive right to prevent third parties from the act of using such process, and from the act of using, offering for sale, selling or importing for those purposes the product obtained directly by that process in India.

The right to exclude others from the acts described above further enables a patentee (either by themselves alone or with a co-owner) to take legal action against third parties who are found to be making, using, offering for sale, selling or importing such products in India.

Based on the rights of a patentee and subject to any overarching provision under the Act, a patentee may be able to initiate a lawsuit against entities believed to be infringing their patent. Under Section 108 of the Act, the reliefs that may be claimed in a suit for infringement include an injunction as well an option to claim either damages or accounts of profits. Subject to a patentee succeeding at trial and the court ruling in favour of the patentee, the court may grant the relief of a permanent injunction, as well as damages or accounts of profits as sought by the patentee. The court may also order seizure and destruction of the adversary’s infringing goods if it deems fit.

Apart from the above, at the interim stage, a patentee may also seek granting of an interim injunction against the adversary until the suit is finally adjudicated on and disposed of.

The Act also sets out the obligations of a patentee, including compliance with key statutory requirements such as Section 146 (working statements/Form 27). Patentees must disclose the extent of the invention’s commercialisation, including revenue generated and number of licences granted, and must confirm that public requirements are being met. They must also comply with Section 8, which requires periodic disclosure of corresponding foreign patent applications.

As regards public information qua applicable patents, India has no system for the provision of public information listing applicable patents in relation to certain products or processes, either equivalent to the FDA’s Orange Book in the USA or otherwise.

Indian patent law strictly prohibits extension of the maximum term of protection for patents once this has lapsed. With an explicit statutory bar on evergreening under Section 3(d) of the Act, India does not provide any further protection, including in the form of supplementary protection certificates or even patent-term adjustments or extensions.

The Act permits third parties to participate during the grant proceedings.

At the pre-grant stage, when the patent application has been published but not granted, any person, including a third party, may, in writing, file a pre-grant opposition before the Controller of Patents (the “Controller”), challenging such patent application on any of the grounds stated under Section 25(1) of the Act.

Once such pre-grant opposition is filed, the Controller assesses whether a prima facie case for an opposition exists. If the Controller is satisfied that the prima facie case is made out, the Controller notifies the applicant about the representation of opposition and provides the applicant with an opportunity to respond to said representation of opposition. Thereafter, an opportunity for oral hearing is provided to both the opponent and the applicant before a final decision on grant or refusal is issued.

An applicant has the option of filing a review application before the Controller, or may prefer to appeal against the decision, order or direction of the Controller before a High Court of relevant jurisdiction.

An application to the Controller requesting review of their decision under Section 77(1)(f) of the Act is to be made within one month of the date of communication of such decision, on the basis of discovery of any new matter or evidence not previously known or any patent error on the face of the record.

The applicant also has an alternative option of exercising their right to appeal under Section 117A of the Act before a High Court of relevant jurisdiction, against the orders of a Controller, in certain specified circumstances, including those pertaining to refusal of a patent application.       

If there is any failure on the part of a patentee to file renewal fees (from the expiry of the second year), the patent ceases to have effect, and the subject matter covered by said patent is also excluded from any protection.

To remedy the lapsing of a patent on account of non-renewal, the patentee can, with the leave of the Controller and within 18 months from the date on which the patent ceased to have effect, make an application under Section 60 of the Act for the restoration of such patent. Said application must contain a statement fully setting out the circumstances that led to the failure to pay the prescribed fee, and must provide further evidence therein, as necessary.

If the Controller is prima facie satisfied that the failure to pay the renewal fees was unintentional and that there has been no undue delay in making the application, this is published for any opposition from any person interested. Based on the filing of such opposition and its disposal, the Controller may permit the patentee to file any unpaid renewal fees and such additional fees as may be prescribed, and to restore the lapsed patent.

The Act permits amendment of a granted patent to the limited extent of incorporating actual facts or a disclaimer, correction or explanation. No amendments are permitted to enable addition of any new subject matter, either by way of claiming or describing a matter not in substance disclosed or shown in the specification before the amendment, or by any claim of the specification that does not fall wholly within the scope of a claim of the specification before the amendment. Thus, amendments to a granted patent are only permissible if they are clarificatory and are within the scope of the claims as granted.

An application for amendment may be made by way of an application to the Controller under Section 57 of the Act, stating the nature of the proposed amendment as well as the reasons for seeking such amendment. Said application is also published for opposition, if any, before the Controller finally adjudicates on approval or rejection of such request. The application may be allowed by the Controller provided no suit or proceeding is commenced before or after filing of the application to amend. Such a request may also be made during an ongoing revocation proceeding before the High Court, wherein the patentee may be permitted to amend their complete specification.

Such an amendment, if permitted by the Controller or the courts, will be deemed to form a part of the specification, and will thereafter be published.

For an action against infringement of a patent, a patentee may consider issuing a legal notice to the adversary bringing to their notice the patent and the claims being infringed, as well as delineating their rights thereunder.

The patentee may also initiate a pre-suit mediation, which would allow both the adversary and the patentee to resolve the dispute amicably and in a timely and cost-effective manner. In fact, Section 12A of the Commercial Courts, Commercial Division and Commercial Appellate Division in the High Courts Act, 2015 (the “Commercial Courts Act”) specifically mandates compulsory pre-institution mediation in the case of a commercial suit above a specified value, provided the applicant is not seeking urgent interim relief. If urgent interim relief is being sought, a litigant may approach courts directly without any pre-suit mediation. The Supreme Court has held that violation of the stated provision may attract grounds for rejection of the plaint altogether.

A patentee may also choose to initiate a suit seeking permanent injunction against infringement of their patent, discovery, damages, search and seizure, et al, either before a District Court or before one of the High Courts that enjoys ordinary original jurisdiction in IP matters (ie, the High Courts of Delhi, Bombay, Calcutta, Shimla and Madras), where the patentee resides, carries on business or personally works for gain, or where the infringing activity took place. It is crucial that such suit be initiated by a patentee within three years from the date of the cause of action – ie, infringement of their patent. However, such action for infringement may not be maintainable unless either infringement is established or there exists an imminent threat of infringement, in which case a quia timet action is considered maintainable.

As previously discussed, a third party can file a pre-grant or a post-grant opposition against a patent.

Such interested person may also choose to file a petition for the revocation of a patent or a counterclaim in a suit for infringement of a patent before a High Court, under Section 64(1) of the Act on any of the grounds provided therein.

In order to avoid multiplicity of proceedings that may arise following the granting of a patent (either under Section 25(2) or Section 64(1) of the Act), the Apex Court in Aloys Wobben and Another v Yogesh Mehra and Others, (2014) 15 SCC 360 held that, if any person interested has preferred a post-grant opposition under Section 25(2) of the Act, this would eclipse their right to file a revocation petition or a counterclaim in a patent infringement suit before the court (under Section 64(1) of the Act). Similarly, if a revocation petition is filed by any person interested prior to initiation of a patent infringement suit against them, they would also be disentitled in law from seeking revocation by way of a counterclaim in a patent infringement suit, and vice versa.

In addition to the above and upon expiry of three years from the date of the granting of a patent, an interested person may also file an application under Section 84 of the Act for granting of a compulsory licence. For further information on the process of filing such an application, kindly refer to 10.4 Procedure for Licensing an Intellectual Property Right.

District Courts in India are empowered with original side jurisdiction to entertain and adjudicate on IP disputes. In addition to the District Courts, the High Courts of Delhi, Madras, Calcutta, Bombay and Shimla have first-instance jurisdiction to entertain and adjudicate on disputes concerning IP – including patents – above a certain pecuniary limit.

As regards courts of second instance, under Section 13 of the Commercial Courts Act, appeals from orders of the District Court are heard by a High Court having the appropriate territorial jurisdiction. Further, any appeal from the single-judge bench of a High Court will lie before the division bench of the High Court. Subject to granting of a special leave to appeal, petitions challenging orders of a division bench or even that of the single-judge bench of a High Court may thereafter be referred before the Supreme Court of India.

In Helsinn Healthcare v AET Laboratories (2025:DHC:8655), the Delhi High Court clarified principles of territorial jurisdiction in commercial IP suits involving foreign defendants under Section 20 of the Code of Civil Procedure (CPC). Jurisdiction requires showing that the defendant carries on business within the forum or that part of the cause of action arose there. At the interim injunction stage, the court may consider the defendant’s pleadings and documents, unlike at the stage of deciding a plaint rejection application. Importantly, mere accessibility of a website in the forum state displaying the impugned product does not confer jurisdiction; the plaintiff must prima facie establish that the website specifically targeted customers in the forum state and that a commercial transaction occurred there. As the plaintiff failed to show any customers or product availability in Delhi, the Court held that the test of “purposeful availment” was not satisfied.

In Kubota Corporation v Godabari (2025 SCC OnLine Del 5417), the Delhi High Court dismissed the defendant’s application under Order VII, Rule 10 CPC seeking return of the plaint for lack of territorial jurisdiction. Relying on the plaint averments, the Court held that it could not be said that no cause of action arose within its jurisdiction. The plaintiff’s investigator’s communication showing an offer for sale and delivery of the impugned product in Delhi was sufficient to establish part of the cause of action under Section 48 of the Patents Act and Section 20(c) CPC, with the issue of jurisdiction to be finally decided at trial.

No specialised body or organisation exists per se for the resolution of IP disputes.

However, in 2021 the Delhi High Court established a specialised IP division dedicated solely to hearing fresh and pending disputes pertaining to IP, revocation petitions and any appeals arising from decisions of the Indian patent, trade mark and copyright offices. Further, in April 2023 the High Court of Madras also announced the establishment of a specific IP division.

Prior to filing a lawsuit, the patentee or the litigant has to ensure compliance with the obligations of a patentee as enshrined under the Act (and as discussed previously; please see 1.5 Rights and Obligations of Owners of Intellectual Property Rights).

Additionally, a patentee may also be required to provide a notice of infringement to the adversary and to initiate a pre-suit mediation if no urgent interim relief will be sought in the suit. See 2.1 Actions Available Against Infringement in this regard.

Pertinently, a suit for infringement of a patent may only be filed once this has been granted. No remedy for infringement of a patent prior to its granting – including by way of a lawsuit – is available to a patent applicant. Thus, recording of a patent with the Indian Patent Office is not required.

Parties in IP matters, including patent litigation matters, need not be represented either in proceedings before the Indian Patent Office by a patent agent or before the courts by an advocate. A party may choose to appear and prosecute the proceedings by themselves.

Interim injunctions are available as a remedy in suits relating to infringement of a patent. Ex parte injunctions are rare and are only granted in very limited circumstances wherein the plaintiff is able to prove grave and serious prejudice to its rights by the defendant, who may not have launched the product commercially, such as in the case of quia timet actions.

For the granting of an interim injunction, the court generally takes three considerations into account based on the notable English decision of American Cyanamid Co v Ethicon Ltd, 1975 AC 396, as follows.

Prima Facie Case

The plaintiff must demonstrate, prima facie, the validity and infringement of the patent (likelihood of infringement in the case of process patents). If the defendant has been able to raise a credible challenge to the validity of the suit patent or to demonstrate non-infringement, a preliminary injunction may be denied.

Balance of Convenience

This takes into consideration the benefits of granting the injunction in favour of the plaintiff, as compared to the hardships faced by the defendant (who may have already made significant investments or who is yet to launch such product in the market) in enforcing the injunction, including:

• whether or not the patented invention was being worked by the plaintiff in India;
• the time period of infringement; and
• the status and size of the defendant, et al.

Further, whether such injunction would be in the public interest is considered.

Irreparable Loss

This takes into account whether the loss, if any, faced by the plaintiff can be compensated for in monetary terms. Some aspects include:

• erosion of brand value;
• price erosion;
• royalties being sought from other licensees in the country;
• ability to recall products form the market; and
• ability to quantify the exact amount of losses caused to the plaintiff, et al.

A finding that a loss can be easily compensated for in monetary terms may render a case against the granting of an interim injunction.

There is no system for a potential opponent in India to file a protective brief.

It is highly recommended that, prior to launching any product in the market or filing a patent, an entity or a potential opponent undertakes a freedom-to-operate search or obtains an opinion from a qualified patent attorney to confirm whether or not its product may pose a risk for infringement. Such an opinion may also prove instrumental before the court for establishing the bona fides if any action for infringement is taken against it in the future.

However, if an opponent is certain of their case of non-infringement, they may file a pre-emptive declaratory action for non-infringement under Section 105 of the Act, stating that use by them of any process, or the making, use and sale of any article by them, would not constitute an infringement of the patent which may be asserted against them. It is pertinent to note that invalidity of the patent cannot be questioned in the declaratory action brought under Section 105.

Further, upon receipt of a legal notice, an entity may also seek to initiate a suit for a groundless threat of infringement under Section 106 of the Act, on the grounds that a threat/notice of infringement is unjustified or baseless, seeking relief for declaration of non-infringement and an injunction against continuance of threats, as well as damages sustained by the plaintiff. The original burden of proof lies on the filing party to prove non-infringement, and thereafter the burden shifts to the defendant to prove infringement; failure on the part of the defendant to prove this will entitle the plaintiff to relief.

In this regard, upon receipt of a legal notice, it is also recommended for potential opponents to file a caveat (Section 148A of Code of Civil Procedures 1908) before Indian courts (potential forums), in order to avoid any adverse order (including an ex parte injunction order) being passed without getting a chance to be heard before the court, and to ensure that they are represented on the very first day of the hearing.

The limitation period for initiation of a patent infringement action is three years from the date of infringement. A cause of action may be continuous or recurring, and each act would constitute a separate cause of action.

Upon initiation of the suit, a party may file an application requesting the court to direct the other party to provide the requisite information or materials to the applicant, by way of:

• an application for interrogatories under Order XI, Rule 2 of the Commercial Courts Act, 2018;
• sending a Notice of Production of Documents under Order XI, Rule 5 of the Commercial Courts Act, 2018; or
• an application requesting discovery by documents under Order XI, Rule 1(6) of the Commercial Courts Act, 2018.

However, for discovery of information, it is necessary for the initial burden of proof to have been discharged by the applicant regarding why such information is necessary for adjudication of the dispute. Further, discovery under Order XI cannot be used as a fishing enquiry or to seek to completely substitute the burden of proof that exists on a party. If the recipient of a Notice of Production under Order XI, Rule 5 has failed to produce the concerned documents without giving any sufficient reason for non-production, the court may draw an adverse inference against such recipient party with reference to the non-production of such documents.

In the case of process patents, under Section 104A of the Act, only when the plaintiff/patentee proves that the defendant’s product is identical to the product that is directly obtained from the plaintiff’s process patent may the court direct the defendant to disclose its process to show that this is different from the patented process. Where the products are found to be identical and the defendant nonetheless refuses to furnish the particulars of its process to the plaintiff, the court may draw adverse inference and invoke Section 104A of the Act.

While directing the defendant to disclose its process, the court would protect the trade and commercial secrets of the defendant – eg, by constituting confidentiality clubs. The court has allowed the appointment of a scientific adviser under Section 115 of the Act (read with Order 26, Rules 4, 9 and 10 of the CPC) to assist the court with a question of fact regarding the process adopted by the defendant, with direction to visit the defendant’s manufacturing facility and obtain/confirm the defendant’s process.

In the context of patent infringement of biosimilar drugs, the Delhi High Court in F- Hoffmann v Zydus [2025:DHC:5927], while dismissing the plaintiff’s application for constituting a confidentiality club for accessing the “process” of the defendant’s product filed under sealed cover before the Court, held that under Section 104A of the Act a plaintiff cannot compel a defendant to disclose their process (in a process patent case) without discharging the initial burden of proving that the defendant’s product is “identical” to the product directly obtained by the plaintiff’s patented process. It further clarified that the patentee cannot assume that biosimilarity filings equate to patent infringement and that it has thereby discharged its burden of proving “identity” of products; the patentee/plaintiff must separately establish identity as defined by patent claims.       

The CPC also provides for the plaint to include concise forms of facts material to the dispute constituting the cause of action and establishing jurisdiction, the relief claimed and a statement of the value of the subject matter of the suit.

In a dispute concerning infringement of a patent, the patentee is required to furnish all documents in its power and possession to prove the validity of its patent, including a certified copy of the grant, working statements and evidence of infringement against the adversary. Further, courts may also prescribe the minimum mandate for information and/or documents to be filed; however, the patentee is also free to include other arguments or evidence that help establish the credibility of claims to be made in the plaint, including expert evidence. For instance, the High Court of Delhi Rules Governing Patent Suits, 2022 (the “Patent Suit Rules”) establish comprehensive requirements under Rules 3A and 4A for furnishing in a plaint to be filed for patent infringement, which may vary depending on whether the suit patents cover a product or a process.

No formal provision exists under Indian law that makes class action lawsuits available to litigants/rights-holders (as contemplated under US law), including under the laws relating to IP rights.

The patent rights of the owner of an IP may be restricted/limited in a manner prescribed by the Act. For instance, the rights of the holder of a patent are subject to the Bolar exemption clause under Section 107A of the Act. Such limitation has been read into the Act by way of a notwithstanding clause; as a result, a patentee may not be able to assert its rights against an entity merely using a patented product for research and development. The Delhi High Court in R Squibb v Zydus Lifesciences [2025:DHC:5802] clarified that “manufacturing” under Section 107A is allowed only for clinical trials, and not for commercial sale.

Further, Section 47 of the Act stipulates certain conditions as outside the purview of patent infringement – ie, the government is permitted to import, make or have made on its behalf any patented product or product made by a patented process for purposes “merely of its own use”. A similar but narrower restriction has also been read into the Act for “government use” of granted patents under Section 100 of the Act, which permits the government to use a patented product or process for the “purposes of the government” in accordance with the provisions of the Act.

Section 47 restricts the use of the patented invention by the government “merely for its own use”; however, under Section 100, even third-party agencies can use a patented invention on behalf of the government, but only on the express authorisation obtained by the third-party agency from the government under Section 100(1), and on payment of an agreed royalty or remuneration to the patentee under Section 100(3), based on a contract between the two parties. Section 47 requires no royalties to be paid to the patentee, wherein the patented invention is being used by the government while exercising its sovereign function, whereas, as per Section 100, royalties must be paid to the patentee based on an agreement between the stipulated parties.

A patentee may also find itself unable to assert its rights against third parties under a compulsory licence that may have been granted in view of the reasonable requirements of the public not being met with respect to the patented invention, or if such invention is not available to the public at a reasonably affordable price or is not sufficiently worked in the territory of India.

An action for infringement should necessarily include the patentee and the adversary alleged to be infringing the suit patent. If the suit is initiated by an exclusive licensee of the patentee, they must make the patentee a party to the suit, as either a plaintiff or a defendant.

While no separate demarcation exists between direct and indirect infringement of a patent in India, direct infringement would result from encroaching upon any of the exclusive rights of a patentee stipulated under Section 48 of the Act, without the permission of the patentee. In the context of proving direct infringement of a patent, the Delhi High Court in Conqueror and Another v Xiaomi [2025:DHC:5233] upheld that to prove infringement the independent or principal claim must include all features essential to defining the invention, and all essential elements of the claimed invention must be found in the infringing devices. The Court concluded that the plaintiff’s claim mapping was fundamentally flawed because it failed to demonstrate the presence of all essential features in the defendant’s devices.

However, in cases involving Standard Essential Patents (SEPs), the Indian courts have upheld proving infringement through indirect methods – ie, “indirect infringement”. In the recent case of Philips v M Bathla [2025:DHC:7079], the Delhi High Court upheld that the indirect method requires proving the following steps:

• mapping the patent (A) to the standard (B) – showing that the patent is an SEP; and
• showing that the implementer’s device (C) maps to the standard (B) – showing that the product complies with the standard.

In a process patent infringement, a plaintiff is required to prove that the impugned product of the defendant is identical to the product directly obtained by the patented process. Once proved by the plaintiff, and where the subject matter of the patent is a process for obtaining a new product or where the plaintiff has shown substantial likelihood that an identical product is made by the process but has been unable to determine (despite reasonable efforts) the process actually used by the defendant, the court shifts the burden of proof to the defendant to show (by way of proof) that it is using a process materially different from that of the plaintiff.

As regards practising parts of a patented process outside India, there is no mechanism to enforce a process patent outside the territory of India, as patent rights are inherently territorial in nature. However, importation of a product manufactured by using a patented process without any permission from the patentee may still enable the patentee to file an action for patent infringement in India.

As the scope of patent protection is determined by the claims of the suit patent, the first step in the assessment of patent infringement is the claim construction, to determine the scope of the rights conferred by the patent. Indian courts often read the claims of the patent in light of the description provided in the patent specification. The prosecution history of a patent may also be used to interpret claims and the scope thereof. However, prosecution history alone may not be helpful for interpretation of claims in India, as different countries may have different substantive and procedural requirements that play a crucial role in the prosecution history.

Thereafter, the next stage involves comparison of the elements of the claim and the elements of the infringer’s product or process. Courts often undertake the test of literal infringement to ascertain whether the interpreted claim elements are present in the defendant’s device.

If there appears to be any alteration or modification in the defendant’s device, courts often employ the doctrine of equivalents to ascertain infringement by considering the “pith and marrow” of the invention claimed in the suit patent. Through such examination, the court overlooks any trifling addition/variation in the product of the defendant and instead focuses on the presence of the essential features of the invention to determine infringement or lack thereof.

In the recent case of Medilabo v the Controller of Patents [2025:DHC:10362], it was upheld that the preamble of the claim must not be read as a limitation to the claim unless it recites essential structure/steps, or unless it is “necessary to give life/meaning and vitality” to the claim.

Non-Infringement

This is a key defence to patent infringement, wherein the defendant may assert differences in the product being manufactured by them vis-à-vis the claims of the suit patent, or may assert a completely different process being used by them not infringing the suit patent (ie, may assert their own patent). Non-infringement may also be pleaded by way of patent exhaustion, wherein the defendant may contend that the product has been purchased from the plaintiff or through another authorised third party.

Invalidity

Additionally, the defendant may also avail of an assertion of invalidity by way of a counterclaim under Section 64 of the Act, as mentioned previously. Under Section 107 of the Patents Act, a defendant, while filing a written statement, is entitled to raise every ground on which a patent is vulnerable to revocation under Section 64 of the Patents Act (grounds of revocation of patent) as a ground of defence. The Division Bench of the Delhi High Court in Mold Tek v Pronton Plast [2025 SCC OnLine Del 4883] held that in an infringement action the onus is, at the first stage, on the plaintiff alleging infringement and, at the second stage, on the defendant pleading a Section 107 defence. Once the plaintiff has succeeded in discharging its initial onus to establish that the defendant’s product infringed the plaintiff’s suit patent, the onus stands discharged. Thereafter, while examining the defendant’s Section 107 defence, the onus of establishing that the plaintiff’s suit patent was vulnerable to invalidity on one or more of the grounds envisaged by Section 64 is wholly on the defendant.

The Bench further clarified that, even if in the complete specifications of the suit patent it was stated that the suit patent was novel vis-à-vis prior art, this does not shift the onus under Section 107 read with Section 64 of the Patents Act, to establish absence of novelty of the suit patent vis-à-vis prior art, from the defendant to the plaintiff. The onus continues to remain on the defendant to establish that the suit patent lacked novelty vis-à-vis prior art.

Some other defences that may be raised by a defendant in a suit for patent infringement include the following.

• Bolar exemption clause: under Section 107A of the Act, it is permissible for a defendant to make, construct, use, sell or import a patented invention solely for purposes related to research and development. The seminal judgment of the Delhi High Court in Bayer v UOI, (2019) 78 PTC 521 (DB) clarifies that the rights of a patentee under Section 48 of the Act are subject to the provisions of Section 107A. 
• Parallel importation: Section 107A(b) of the Act further permits an entity to import a patented product into India if it is duly authorised under the law to produce, sell and distribute the product in India.
• Gillette defence: under said defence, a defendant may assert that its activities alleged by the plaintiff to be infringing are essentially covered by the prior art which encompasses all features of the claimed subject matter. In the recent case before the Delhi High Court of Novo Nordisk v Dr Reddys [2025 SCC OnLine Del 8702], while deciding the interim injunction application, the Court held that the defendant successfully raised a credible challenge on the basis of the Gillette defence (Semaglutide – ie, inventive compound as claimed under the suit patent was found to be covered and disclosed in an expired genus patent). Note that the decision is under challenge before the Appellate Court.
• Innocent infringement: a defence of innocent infringement may play a crucial role in reducing the accounts of profits and/or damages that may be granted against such defendant. The defendant has to prove that, on the date of infringement, they were not aware and did not have any reasonable grounds to believe that the plaintiff’s patent existed.
• An additional layer of defence available in SEP matters is for the defendant to contend that they were willing to obtain a FRAND licence from the SEP owner but were refused.
• Unclean hands: a common law principle grounded in inequitable conduct, an argument of unclean hands may be brought by the defendant, evincing acts that attribute falsehood to the plaintiff vis-à-vis a patent obtained by false suggestion or misrepresentation.
• Delays/laches: a preliminary injunction may not be granted in a case where there is acquiescence or unexplained delay, without cause and which causes material prejudice to the defendant. Delay along with acquiescence can lead to denial of a permanent injunction.
• Estoppel: as regards estoppel, courts often consider statements made by a patentee in relation thereto, or a corresponding patent in other countries, at the prosecution stage. In view of this, a plaintiff may be estopped from claiming otherwise before the courts in India (prosecution history estoppel).

It is also pertinent to note that Indian courts have refused to grant injunctions for expired patents. The Delhi High Court in Kabushiki Kaisha v LMW Limited [2025:DHC:5122] recently reiterated that, once the patent has expired, the injunction ceases to have practical relevance. While dismissing the interim injunction application for an expired patent, the Court observed that, even though the plaintiff may have a prima facie case, the fact of “expiry of the patent of the plaintiff” becomes a crucial factor for consideration while adjudicating the relief of injunction.

In a patent infringement action, parties may file affidavits of technical experts and rely on their evidence to substantiate their case at trial, or even at the stage of filing the suit to substantiate their case of infringement. However, the scope of the expert evidence during trial should be rooted in the pleadings filed in the suit.

Under Section 115 of the Act, scientific advisers may be appointed by the court suo moto to advise in its inquiry or report on any question of fact or of opinion (not involving a question of interpretation of law). In particular, the Delhi High Court in Merck Sharpe v Glenmark, (2015) 6 SCC 807 observed that, in highly technical matters involving chemical compounds, the court must rely on the opinion of experts in the field whose testimony is found trustworthy and reliable and is supported by documents. Notably, for matters to be filed before the Delhi High Court, Rule 4 of the Patent Suit Rules makes provisions for filing expert reports for infringement analysis as well as a laboratory analysis report, if any.

Further, Rule 6 of the Delhi High Court (Original Side) Rules 2018 states that the court, on its own motion or on an application of any party, may permit an expert witness to testify by way of recording of their testimony, which includes techniques such as “hot-tubbing”, whereby expert witnesses give evidence simultaneously, in each other’s presence and in front of the judge. This enables identification of key issues of a dispute, and allows common resolution (Rule 16 of the Intellectual Property Division Rules, 2022 read with Rules 8 and 9 of the Patent Suit Rules).

No formal mechanism exists in India for a “Markman” hearing such as in the USA, as there is no separate procedural step for claim construction. Instead, claim construction is handled as part of the trial. Any disputes concerning the construction of claims are framed as issues during the case management hearing.

Notably, the Delhi High Court’s Patent Suit Rules require the parties to file a claim-construction brief before the case management hearing, to enable courts and parties to assess whether there are any disputes in relation to the construction of the claims.

While the Act specifically provides for an independent scientific expert, the court has, in some cases, also appointed amicus curies to assist with questions of law. However, this is the prerogative of the court and not of any party.

Section 64 of the Act allows for a party to file either a counterclaim for revocation/invalidation of a patent in the infringement action itself or to initiate separate proceedings for revocation by filing a revocation petition. The revocation petitions can be filed even without an infringement suit, by any person interested. However, a party cannot avail of both mechanisms (counterclaim and revocation) simultaneously, as the right to initiate separate proceedings by a revocation petition is necessarily eclipsed once the accused infringer files a counterclaim for revocation within an infringement action, and vice versa. This position has been confirmed by the courts in various decisions.

Nonetheless, recently in Macleods v the Controller of Patents [2025 SCC OnLine Del 1833], the Division Bench of the High Court of Delhi clarified that taking a defence of invalidity under Section 107 in a written statement of a suit does not bar the party from filing an independent revocation petition under Section 64.

If the infringement action is filed within the timeline permitted for filing a post-grant opposition, the defendant would have the choice of either filing a counterclaim in the infringement action or pursuing post-grant opposition proceedings before the Indian Patent Office.

Partial revocation or cancellation of a patent is possible under Indian patent law. The Act allows for the revocation of a patent on specific grounds, as enumerated in Section 64. The court may revoke a patent in part if certain claims are found to be invalid while others remain valid – ie, relief may be granted qua valid claims even if certain other claims have been found to be invalid.

Amendments are possible in revocation or cancellation proceedings. As per Section 58 of the Act, during proceedings for the revocation of a patent, the High Court may allow the patentee to amend their complete specification, provided it is deemed appropriate. This amendment may also be subject to costs. 

Revocation and infringement cases are generally not heard together as they would be two different proceedings. However, in a suit for infringement, where a counterclaim seeking to invalidate the patents is filed, both proceedings would typically be heard together. Nevertheless, if a revocation petition is filed independently, and an infringement suit is also filed independently, it is theoretically possible that they would be adjudicated separately – though, practically, the court is likely to combine these and hear them together.

The procedures for IP rights proceedings are largely governed by specialised statutes such as the Trade Marks Act, 1996, the Copyright Act, 1957 and the Patents Act, 1970 (along with the CPC). Additionally, courts may also issue rules for these suits which would be valid in the jurisdiction of that specific court, such as the Patent Suit Rules and the Delhi High Court Intellectual Property Rights Division Rules 2022, issued by the Delhi High Court for all matters filed before its IP division. 

The timeline for the proceedings would vary depending on the urgency of the suit and the factual matrix. Typically, interim relief would be adjudicated on within three to six months of initiation of the suit. In rare cases, where extremely urgent relief is applied for, courts may grant ex parte or ad interim relief on the first day of the suit itself.

For final relief in the suit, including trial, the judgment may take up to 12 months or more, subject to other timelines being complied with. The timeline in the suit is statutorily mandated in the following manner.

• From receipt of summons, the defendant has 30 days to a maximum of 120 days to file its written statement.
• Thereafter, the plaintiff is provided 30 days to 45 days to file its replication of the written statement.
• After completion of pleadings, procedural hearings for the trial begin (marking of exhibits, admission/denial documents, etc). Thereafter, case management hearings are held where issues are framed and a schedule for trial is fixed. While the statutory timeline for commercial suits (including IP suits) is six months, this may be extended if sufficient reasons have been provided for the delay.
• The plaintiff then leads evidence, by way of affidavit, pursuant to which its witnesses are cross-examined. Similarly, the defendant also leads evidence, by way of affidavit, pursuant to which its witnesses are cross-examined.

Final arguments are heard, and the case is then reserved for judgment. It is also possible to appeal the judgment, before a larger bench, within 60 days from its pronouncement.

Infringement suits/revocation proceedings in India are determined by a judge, whereas the initial prosecution/opposition to the patents would be decided by the Controller of Patents. Some courts in India (such as the Delhi High Court and the Madras High Court) have specialised IP divisions where the judges therein deal exclusively with IP cases.

Further, although some judges may be technically qualified, this is not a necessity, and there will also be judges without any technical background. The parties do not get to choose before which judge the matter is placed. However, the plaintiff can, subject to statutory provisions, choose the jurisdiction for initiating the suit.

The Commercial Courts Act provides for mandatory pre-suit mediation, which can only be exempted if urgent interim relief is sought. Recently, in Novenco A/S v Xero Energy [2025 INSC 1256], the Supreme Court of India, while interpreting the phrase “contemplates any urgent interim relief” in Section 12A of the Commercial Courts Act, 2015, specifically concerning an action for patent and designs infringement, held that mere delay in bringing an action does not legalise an infringement and this cannot defeat the right of the proprietor to seek injunctive relief against the dishonest user. The Court held that, in actions alleging continuing infringement of IP rights, urgency must be assessed in the context of the ongoing injury and the public interest in preventing deception, and mere delay in institution of a suit by itself does not negate urgency when the infringement is continuing.

However, even after the initiation of the suit, parties can seek referral to mediation. Alternatively, the parties could resolve their dispute and, subject to the terms of their settlement, file applications under Order 23, Rule 1 of the CPC (for withdrawal of the suit) or Order 23, Rule 3 of the CPC (for settlement). The latter would allow for the settlement to be recorded in the order of the court itself.

Courts in India have clarified that parallel proceedings in another jurisdiction alone do not justify staying the current proceedings. The case of InterDigital v Xiaomi, [2021:DHC:1493] highlighted that overlapping issues between Indian and Wuhan courts do not warrant anti-suit injunctions or stays based solely on potential conflicting orders.

The principle established in various judgments emphasises that anti-suit injunctions should only be considered when foreign proceedings are oppressive or vexatious. The courts have further clarified that the mere existence of an anti-suit injunction from a foreign court does not automatically influence Indian proceedings, which must be assessed on their own merits. Although not statutorily recognised, the influence of other proceedings, especially concerning validity challenges, is significant – in particular for interim relief. If a patent’s validity is challenged in a parallel jurisdiction, it could impact on current infringement cases to the extent that the court may take such proceedings into account. This would not, however, stay proceedings.

As stated in 1.5 Rights and Obligations of Owners of Intellectual Property Rights, the reliefs provided for a patentee are enshrined in Section 108 of the Act, and are a permanent injunction and, at the option of the patentee, damages or an account of profits. During the pendency of the proceedings, the patentee can also seek interim relief by way of interim injunction and monetary deposits.

Once infringement is established, an injunction must follow. The quantum of damages and/or account of profits depends on the evidence of loss proved. Damages can include provisional damages, punitive damages and enhanced damages, depending on the factual matrix of the case (such as punitive or enhanced damages for wilful infringement, for repeat infringement, etc). In a recent decision in the case of Ericsson v Lava, [2025:DHC:2698], the Delhi High Court held that, in the case of damages in respect of SEPs, they will be calculated from the date of notice when the infringement of the Indian patent was first asserted, and not from the date of publication of the patent application. Further, the court may also order payment of attorney fees (known as legal costs) as well as other costs per actuals; however, this awarding of costs is entirely at the discretion of the court, and is primarily governed by Section 35, 35A and 35B of the CPC.

In the case of non-compliance with the court order, the court can, on application by a party, initiate contempt proceedings against the defaulting party, which could lead to imprisonment, a fine, compensation or all of these.

If a defendant succeeds, the court is likely to grant relief, including a declaration of non-infringement. The court would typically also order that costs be borne by the plaintiff, and that any damages that the defendant has established also be granted to the defendant. The extent of the damages and costs (including attorney fees) is also at the discretion of the court, but would typically be calculated on the basis of some objective material on record. Further, the defendant may also be entitled to damages awarded due to interim relief, if at the time of granting said relief the plaintiff had undertaken to compensate the defendant if the latter succeeded at trial.

Similar remedies apply for all IP rights in India – ie, injunction, damages or account of profit and costs. However, the plaintiff can claim relief either for damages or relief for account of profits, with the right of the plaintiff to make an informed choice between damages and profits in the course of trial in light of information revealed on discovery and the evidence at the trial.

During appeal – usually on the first day – the appellant would have to establish that it would suffer irreparable harm if the injunction were to continue during the pendency of the appeal. The appellate court may then stay the injunction and would usually order a monetary deposit in its place. However, this is discretionary, and the appellate court may instead not stay the injunction and allow the injunction to continue during the pendency of the appeal.

The provisions for appeal are codified primarily under the Commercials Courts Act, the CPC and the Patents Act, 1970. These provisions provide the forum and the timeline for the appeal.

The appeal will involve a review of the grounds raised therein, which typically relates to the entire decision. However, the onus would be on the appellant to point out the errors in the first decision, both legal and factual, based on which it has appealed the decision. Pertinently, the appellate court would usually assess whether there were errors in applying the law or in interpreting the patent claims, rather than re-examining the evidence presented at trial. The courts tend to respect the factual findings made by the lower courts unless there is a substantial reason to overturn them based on legal grounds.

The main cost before filing a patent lawsuit involves seeking legal advice on the chances of success, which includes reviewing the patent, infringement claims, and gathering evidence by investigating the market and deciding on the proper jurisdiction. Additionally, Section 5 of the Mediation Act, 2023 allows for pre-suit mediation, with costs arising from the mediation application and attorneys’ fees, which depend on the chosen law firm.

The calculation of court fees is as per the Court Fees Act, 1870 and the specific Indian state amendments to said Act. Therefore, the court fees payable for instituting a patent suit and seeking injunctive and declaratory relief will vary across different states in India.

When any monetary relief is claimed, the court fee for such relief would be a certain percentage of the damages or reliefs sought. Therefore, court fees are calculated based in particular on the reliefs claimed in a suit.

The party who initiates the litigation is required to pay the court fees. Regarding attorneys’ fees, both parties are required to bear their own expenses until the final judgment is pronounced.

The party who succeeds in the litigation may request reimbursement of the legal and actual costs incurred during the proceedings. However, the decision to grant the costs in favour of the winning party lies at the discretion of the court.

Further, in certain cases where a party initiates a patent suit, the suit will nonetheless be withdrawn before the final adjudication if the parties were able to reach a settlement. At this stage, the party who had instituted the suit can request the court for a refund of the court fees. However, the decision regarding a refund of court fees is purely at the discretion of the court.

Indian courts generally encourage parties in patent infringement cases to resolve disputes through alternative dispute resolution (ADR), especially mediation, either before or after filing of the suit. According to the Commercial Courts Act, pre-suit mediation is mandatory if urgent interim relief is not sought. If a lawsuit has already been filed, courts may refer parties to mediation either on request of parties or voluntarily, even sometimes without their consent if the situation so demands in the opinion of the court, as outlined by the CPC and the Delhi High Court’s Patent Suit Rules.

To initiate pre-suit mediation, parties must submit an application with dispute details; a mediator is then appointed jointly or by the mediation centre. If settlement is reached, an agreement reflecting the terms is signed by both parties. All discussions during mediation remain confidential, and cannot be disclosed or used in litigation. Apart from court-directed mediation, parties may also resolve disputes via private negotiation.

As per Section 68 of the Act, assignment of a patent must be in writing, contain all terms and conditions, and be duly signed by parties.

Further, as per Section 69 of the Act, the assignee will have to apply in writing to the Controller of Patents for registration of their title or the assignment agreement, accompanied by two copies of the assignment agreement.

Moreover, in cases where the patent is granted to two or more persons, a patent or a share in a patent cannot be assigned without the consent of the other person(s).

In order to assign an Indian patent, both parties will have to draw up an assignment agreement, which will thereafter be duly executed by them. This agreement must outline all terms and conditions that were agreed upon between the parties. An appropriate stamp duty is to be paid, as per the Indian Stamp Act, 1899.

Once the agreement is executed, the assignee has to apply to the Controller of Patents in the prescribed form (Form 16) for registration of their title over the patent. Once the Controller is satisfied, the assignee will be registered as proprietor or co-proprietor of the patent in the register of patents. This entry in the register will also contain the particulars of the instrument by which the assignee has derived its title over the patent or share of a patent.

As per Section 68 of the Act, while licensing a patent, both the licensor and licensee have to execute a patent licence agreement, which should contain all terms and conditions that were agreed upon between the parties during the negotiations. A licence will not be legally valid unless it has been rendered in writing.

Once the agreement is executed, as per Section 69 of the Act, the licensee must apply in writing to the Controller for registration of their title; upon request, the licence agreement provided to the Controller will be kept confidential. 

Further, in cases where the patent is granted to two or more persons, a patent or a share in a patent cannot be licensed without the consent of the other person(s). Further, Section 109 of the Act provides that even an exclusive licensee can institute a suit for infringement against a party; however, the licensor (ie, the patentee) would have to be made a party to the suit, either as a plaintiff or as a defendant – otherwise, no relief can be granted against the infringing party. 

Moreover, Section 140 of the Act prohibits insertion of certain clauses into a licence agreement. For instance, a licensor cannot prohibit the licensee from acquiring and using any product other than the patented article or article made by a patented process from another licensor. In addition, there cannot be any clauses relating to exclusive grant-back, prevention to challenges of validity of the patent, or coercive package licensing.

In India, the following types of licences apply.

• A voluntary licence, wherein the patentee voluntarily agrees to license the patent.
• A compulsory licence, wherein only following expiry of three years after granting of the patent, and upon application submitted by any party, the Controller of Patents will grant a compulsory licence for the patent if the applicant is able to show that:
1. the reasonable requirements of the public regarding the patented invention are not being met;
2. the patent is not available to the public at an affordable price; or
3. the patent is not being worked in India.

For granting of a voluntary licence for patents, both the licensor and licensee will first have to draft and execute a licence agreement. This agreement will include:

• the type of licence (exclusive or non-exclusive);
• the scope of the licence (which patents are being licensed, the territories that the licence will cover);
• duration;
• obligations of licensor and licensee; and
• royalty terms.

Once the agreement is executed, the licensee has to apply in writing to the Controller for registering their title over the patent. This will be accompanied by the copies of the licence agreement.

Regarding the compulsory licence, under Section 84 of the Act, an application has to be made to the Controller stating the nature of interests of the applicant, based on which the application is being made. The Controller will take into account:

• the nature of the invention;
• the ability of the applicant to work the invention;
• the ability of the applicant to undertake any risk in providing the capital required for working the patent; and
• whether the applicant had made any effort to obtain a licence from the patentee but failed to obtain one within a reasonable period.