Use the Lexology Navigator tool to compare the answers in this article with those from other jurisdictions. 

Enforcement through the courts


What are the most effective ways for a patent owner to enforce its rights in your jurisdiction?

By far the most common way for a patent owner to enforce its rights is by filing an infringement action in a federal district court – the court of first instance in the US federal judicial system. Although the number of such actions is declining, in recent years 5,000 to 6,000 such actions have been filed annually.

The only other significant way to enforce a patent is by requesting the US International Trade Commission (ITC) to commence an investigation into whether goods being imported into the United States infringe a patent and therefore violate US trade law. The ITC is an independent quasi-judicial administrative agency that has investigative powers on matters relating to trade. To commence such proceedings, the patent owner must file a complaint, which is typically much more detailed than a corresponding district court complaint, and the ITC will evaluate the allegations and decide whether to initiate an investigation. In recent years, there have typically been 35 to 50 such investigations commenced annually. The usual remedy for a successful complainant is an order excluding the infringing imports; such orders are enforced by the US Customs and Border Patrol. A complainant may also obtain a cease-and-desist order prohibiting further sale or disposition of infringing products within the United States. 

What scope is there for forum selection?

There are 94 US federal judicial districts and the plaintiff chooses in which of these it wishes to commence an infringement action. Until recently, the only real constraint was that the plaintiff had to choose a district in which the defendant was subject to personal jurisdiction – that is, the defendant had sufficient contacts with the forum that it was reasonable for it to be sued there. For companies that sell products and services throughout the United States, this standard was relatively easy to meet and such companies were usually subject to suit in any judicial district. However, the Supreme Court has recently held that a defendant corporation may be sued only where it is incorporated or it has a “regular and established place of business” and has committed an act of alleged infringement. This will greatly restrict where patent infringement actions may properly be brought. However, different rules apply to non-US corporations which may still be subject to suit more widely.

As a practical matter, a small number of judicial districts have traditionally accounted for a high proportion of all patent cases. These include the Eastern District of Texas, the District of Delaware, the Northern and Central Districts of California, and the District of New Jersey. By filing a case in one of these districts, plaintiffs can increase their chances of being assigned a judge with significant experience in overseeing patent cases. It remains to be seen exactly how the recent change in venue law will affect the distribution of patent cases, but it is widely expected that the number of cases filed in the Eastern District of Texas will be significantly reduced.


What are the stages in the litigation process leading up to a full trial?

A case begins with an exchange of formal allegations, usually consisting of a complaint by the plaintiff and an answer by the defendant. The defendant also has the opportunity to present counterclaims, to which the plaintiff responds in a reply. Collectively, these allegations are known as the ‘pleadings’, which frame the issues to be litigated. In recent years, the pleading requirements in patent cases have become stricter, but US pleadings still typically contain less detail than comparable documents in other major jurisdictions. At the pleading stage, the defendant also has the opportunity to move to dismiss some or all of the plaintiff’s claims, in effect arguing that there is no reason to proceed with the litigation because the allegations are in some way defective on their face.

After the exchange of pleadings, the case will progress to a large-scale exchange of information known in US practice as ‘discovery’. This begins with each party’s mandatory disclosure of certain basic categories of information (eg, the identities of witnesses believed to have relevant knowledge). Thereafter, the parties can request disclosure of business documents that may be relevant to the issues in dispute. This usually occurs on a large scale; it is common for hundreds of thousands or even millions of pages of documentation to be exchanged in patent cases. Discovery also includes the deposition of the parties’ employees and, less frequently, third-party witnesses. A ‘deposition’ is the taking of sworn oral testimony that can be used at trial or in support of other pre-trial submissions. Other tools available in the discovery stage of a case are:

  • interrogatories – requests for formal answers to written questions; and
  • requests for specific facts to be admitted for purposes of the litigation. 

Confidential information provided to an adversary in the discovery process is almost always subject to a court order (a ‘protective order’), limiting the disclosure and use of the information to that which is necessary for the lawsuit. 

Patent infringement actions usually include a stage directed to the interpretation of any disputed terms within the patent claims. These proceedings mostly take the form of a court-mandated dialogue between the parties to identify disputes, followed by written briefing on the meaning of disputed terms and then a hearing (referred to as either a claim construction or a ‘Markman’ hearing). After the hearing, the court will issue its ruling. In some cases, this may effectively resolve the litigation by creating a situation in which one party cannot prevail given the court’s interpretation.

Some judicial districts have their own rules regarding the procedures to be followed in patent cases.  These rules usually require the provision of detailed written contentions explaining a party’s position on infringement or invalidity. In some districts, the rules provide for preliminary and final contentions, with the latter usually required shortly after the court issues a claim construction ruling.   

After document discovery and depositions of fact witnesses, there is typically a stage devoted to expert witness discovery. This begins with each expert witness’s disclosure of a report describing the substance of his or her expected testimony. Typically, there is a first round of reports regarding issues on which the disclosing party has the burden of proof (eg, infringement for the plaintiff, invalidity for the defendant), followed by a second round in which each party responds to the disclosures provided by its opponent. After the exchange of reports, depositions of the expert witnesses take place. 

The last discrete phase of a case before trial preparation and the trial itself is usually devoted to dispositive, or summary judgment, motion practice. Here the parties can file motions seeking judgment in their favour on either a specific issue or the case as a whole. Summary judgment is appropriate when no material facts are in dispute, for example:

  • when the facts necessary to enter judgment cannot reasonably be contested; or
  • where the parties’ sole dispute is over an issue of law. 

Again, this phase typically consists of written briefing followed by an oral hearing and decision. If the case is not resolved, the remaining issues can then be tried.

How easy is it for defendants to delay proceedings and how can plaintiffs prevent them from doing so?

Generally, the court will set a schedule at or near the beginning of a case, which can be changed only by a further court order. This means that defendants cannot unilaterally delay proceedings.  

How might a party challenge the validity of a patent through the courts in anticipation of a potential suit for infringement being issued against it?

US law provides for declaratory judgment actions by which parties can challenge the validity of a patent without waiting to be sued for infringement. There are certain legal requirements to ensure that a dispute is sufficiently ripe and well defined in order for a declaratory judgment action to proceed. If these requirements are not met, the case could be dismissed.

At trial

What level of expertise can a patent owner expect from the courts?

This varies widely between – and in some cases within – judicial districts. As noted above, certain districts account for most US patent litigation and within those districts the judges tend to have substantial expertise in patent law. 

Are cases decided by one judge, a panel of judges or a jury?

At the first instance or trial court level, a single judge presides over the case. In most patent infringement cases, either or both parties request trial by jury (discussed in greater detail below). If neither party requests trial by jury or the case is not one in which the right to a jury trial exists, the same judge who presides over the pre-trial proceedings will decide the case. The parties may also consent to trial before a magistrate judge (a lower level officer within the federal judicial system), but this is relatively rare in practice.

Appeals go to a single court, the Federal Circuit, where they are almost always heard by a panel of three judges.

If jury trials do exist, what is the process for deciding whether a case should be put to a jury?

The right to trial by jury depends on whether damages are sought as part of the relief. If damages are sought, either party has the absolute right to request a jury. In some cases – most notably those involving patents alleged to cover generic drugs – the defendant has yet to enter the market and money damages are not available. In this situation, there is no right to a jury trial and the case is decided by a judge. Where the right to a jury exists, it is often exercised, and most patent cases that reach trial in the United States are tried to a jury.

What role can and do expert witnesses play in proceedings?

Expert witnesses are employed in most patent cases litigated in the United States. Typically, the key liability issues (eg, infringement and validity) are addressed by means of opinions from experts in the appropriate field of technology. In addition, it is routine for each side to call one or more experts with training in accountancy or economics to present their positions on damages.   

Does your jurisdiction apply a doctrine of equivalents and, if so, how?

US law does recognise the doctrine of equivalents. This can be applied to find infringement even when the accused product or process falls outside the literal scope of the patent claim at issue. There are two principal ways in which the doctrine of equivalents is articulated: 

  • The first asks whether the accused product or process performs substantially the same function in substantially the same way to achieve substantially the same result as the patented product or process. This is referred to as the function/way/result test. 
  • The second asks whether the differences between the accused product or process and the patented invention are insubstantial. 

Application of the doctrine of equivalents is a question of fact decided by the fact finder (ie, the jury, if there is one). However, the doctrine is subject to certain legal limitations, including the principle that it cannot be used to recapture subject matter given up in prosecution to obtain the patent. The applicability of such limitations is decided by the judge as a matter of law. 

Is it possible to obtain preliminary injunctions? If so, under what circumstances?

Preliminary injunctions can be obtained, but the legal standard for doing so is exacting. To grant a preliminary injunction, the court must consider each of the following factors:

  • whether the party seeking the injunction is likely to succeed on the merits;
  • whether there is a likelihood of immediate irreparable harm if no injunction is granted;
  • the balance of hardships between the parties; and
  • the public interest. 

No single factor is dispositive, but the first two are often more important in patent cases, and failure to establish either likelihood of success or immediate irreparable harm will likely mean that no injunction is granted. Unlike most other interlocutory orders, a decision to grant or deny a preliminary injunction is appealable immediately.

How are issues around infringement and validity treated in your jurisdiction?

In district court actions, validity and infringement are usually considered at the same time. The new post-grant procedures created by the America Invents Act 2011 (ie, inter partes reviews, covered business method patents and post-grant reviews) have led to an increase in situations where validity is effectively decided in the US Patent and Trademark Office (USPTO).  Where a party that has been sued for infringement responds by filing a petition for one of these procedures and the USPTO institutes a review, the court will usually stay the infringement action until the USPTO has issued a decision.   

Will courts consider decisions in cases involving similar issues from other jurisdictions?

US courts rarely rely on decisions from other jurisdictions. In situations involving parallel litigation on corresponding patents, a US court would likely be interested to see the decision of a foreign court, but would not be compelled to follow it. 

Damages and remedies

Can the successful party obtain costs from the losing party?

US law distinguishes between costs and attorneys’ fees. The term ‘costs’ includes only a small number of out-of-pocket expenses (eg, court reporting charges). The prevailing party has the right to recover costs where the case is concluded by a judgment on the merits in favour of that party, but typically such an award is only a few tens of thousands of dollars compared with several million dollars in attorneys’ fees. Traditionally, awards of attorneys’ fees are unusual in US litigation, as there is no general ‘loser pays’ principle. In recent years, the law has changed to make it somewhat easier for the prevailing party to recover attorneys’ fees, but this remains the exception, rather than the norm. 

What are the typical remedies granted to a successful plaintiff?

A successful plaintiff will typically receive damages. In cases between competitors, the plaintiff may also obtain an injunction against further infringement – this is discussed in more detail below.

How are damages awards calculated? Are punitive damages available?

Damages are calculated as either a reasonable royalty or the plaintiff’s lost profits attributable to the infringement.

Reasonable royalties Reasonable royalties are assessed by considering what payment a willing licensor and willing licensee would have agreed to at the time that the infringement began, with the assumption that the infringement and validity of the patent have been established and are known to both parties. This is referred to as a hypothetical negotiation. In recent years, the law has become stricter in the calculation of royalties, with the goal of ensuring that the amounts reflect only the values of the patented intellectual property and no other factors (eg, the value attributable to lock in or network effects, where the patented subject matter became part of a technical or de facto standard). The law has also evolved to try to ensure that where the accused device is a multi-feature product, the royalty is based on no other features than those covered by the infringed patent. This is referred to as apportionment.

Lost profits Lost profits are available in cases between competitors. The measure of damages is the profits that the plaintiff would have made, not those that the defendant actually made as a result of the infringement. With the exception of design patents, there is no remedy of an accounting for profits such as would be available in many non-US jurisdictions. To obtain lost profits, the plaintiff must prove that if not for the infringement, it would have made the sales in question. This is typically done by applying a four-factor test in which the plaintiff proves:

  • the demand for the patented subject matter;
  • the absence of non-infringing alternatives;
  • the sufficient manufacturing and marketing capacity to meet the added demand; and
  • the amount of the resulting profits. 

How common is it for courts to grant permanent injunctions to successful plaintiffs and under what circumstances will they do this?

Before 2005 almost all successful plaintiffs in patent infringement actions obtained permanent injunctions. However, the Supreme Court changed the law to require that the plaintiff prove its entitlement to a permanent injunction.  As a result, non-practising patent owners may have difficulty obtaining injunctive relief. In cases between competing commercial companies, however, it is still common for the prevailing plaintiff to obtain a permanent injunction.    

Timescale and costs

How long does it take to obtain a decision at first instance and is it possible to expedite this process?

The timeframe to obtain a first-instance decision varies significantly between judicial districts. Some courts, most notably the Eastern District of Virginia, have adopted procedures for the fast resolution of civil cases (colloquially, a ‘rocket docket’). In these courts, a trial and first-instance decision in a patent case can be obtained in approximately 12 months. However, in the districts with the most patent litigation, the time to a trial is typically two to three years. Although where a case is resolved by dispositive motion (almost always in favour of the defendant), the decision occurs in less time, because no trial is required. It is possible to ask the court to set a faster schedule than usual, but – absent compelling circumstances – this is unlikely to occur.  Notably, the ITC is required by statute to comply with certain time limits. Thus, in an ITC investigation, a decision on the merits is almost always obtained within 18 months.    

How much should a litigant plan to pay to take a case through to a first-instance decision?

The cost of litigation varies widely, depending on many factors. However, largely due to the discovery process, US litigation is often more expensive than that of other jurisdictions. The cost of bringing a relatively straightforward patent case to trial and first-instance decision is likely to be in the range of $4 million to $8 million. 


Under what circumstances will the losing party in a first-instance case be granted the right to appeal? How long does an appeal typically take?

The losing party in a patent case has the absolute right to appeal to the Federal Circuit. Usually, no appeal can be made until the first-instance court has entered final judgment resolving all issues in the case. After this, an appeal typically takes 12 to 15 months from its commencement to a decision.

Options away from court

Are there other dispute resolution options open to parties that believe their patents to be infringed outside the courts?

US district courts usually require the parties in a civil dispute, including in patent cases, to engage in some form of alternative dispute resolution (ADR) – most commonly mediation.  This may be conducted by a judicial officer (usually a judge who is not presiding over the case) or a private mediator engaged by the parties. Apart from court-ordered ADR, there are no other obligatory dispute resolution mechanisms outside the judicial system. The parties may agree to some form of ADR, but this is voluntary and an unwilling party cannot be compelled to engage in ADR. However, if the parties already have an agreement to arbitrate disputes (eg, as part of a patent licence), such provisions may be enforced. US law has a strong policy in favour of arbitration and courts will not hesitate to compel a party to an arbitration agreement to comply with its provisions. 

Click here to view the full article.