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Patent litigation

Also called patent infringement litigation, patent infringement lawsuit, patent dispute, patent enforcement action, patent suit

Published by Patsnap Team Updated 27 October 2026 20 sources

Definition

Patent litigation is a court action involving the validity or infringement of a patent¹. In the US, whoever without authority makes, uses, offers to sell or sells a patented invention within the United States, or imports it into the United States, during the term of the patent infringes the patent (35 U.S.C. 271(a))².

Which court hears a patent case depends on the country. In the US, federal district courts hear patent cases and the Federal Circuit hears the appeals^3,4. Europe and China are covered below.

Used byPatent owners enforcing a patent, and parties accused of infringing it²

Comes upWhen infringement or validity of a patent is disputed in court¹

Governed byNational or regional law, for example 35 U.S.C. 271 and 282 in the US^1,2, the UPC Agreement in Europe¹² and the Patent Law in China¹⁴

Not to confuse withInter partes review, a trial at the USPTO's Patent Trial and Appeal Board rather than a court action⁵

What a patent case decides

A patent case can raise questions of infringement, validity, claim scope and remedies^1,2,6. The list below uses the US rules as its example.

Infringement. Whether the accused acts fall within 35 U.S.C. 271, which covers direct infringement (271(a)) and also, for example, active inducement of infringement (271(b))². Noninfringement is a defense that must be pleaded¹.
Validity. Invalidity of the patent or any claim in suit on any ground specified in part II of Title 35 as a condition for patentability is also a defense that must be pleaded¹. A patent is presumed valid, each claim independently of the others, and the burden of establishing invalidity rests on the party asserting it¹. See Invalidity search.
Claim scope. The construction of a patent, including terms of art within its claim, is exclusively within the province of the court⁶. See Claim construction.
Remedies. What the court can order if infringement is found. The US remedies are listed in the next section^9,10,11.

Where patent cases are heard

Patents are national or regional rights, so the forum depends on the country. The tabs cover the United States, Europe and China. They are not a complete list of the routes available in each place.

United States

The district courts have original jurisdiction of any civil action arising under any Act of Congress relating to patents, and no State court has jurisdiction over a claim for relief arising under such an Act (28 U.S.C. 1338(a))³.
The Federal Circuit has exclusive jurisdiction of an appeal from a final decision of a district court in a civil action arising under any Act of Congress relating to patents, including where a party has asserted a compulsory counterclaim arising under such an Act (28 U.S.C. 1295(a)(1))⁴.
A civil action for patent infringement may be brought in the judicial district where the defendant resides, or where the defendant has committed acts of infringement and has a regular and established place of business (28 U.S.C. 1400(b))⁷. In TC Heartland v. Kraft Foods (2017), the Supreme Court held that for a domestic corporation, residence under that provision refers only to its State of incorporation⁸.
Courts may grant injunctions in accordance with the principles of equity (35 U.S.C. 283)⁹.
On a finding for the claimant, the court awards damages adequate to compensate for the infringement, but in no event less than a reasonable royalty, and may increase the damages up to three times the amount found or assessed (35 U.S.C. 284)¹⁰. See Willful infringement.
Except as otherwise provided by law, no recovery may be had for infringement committed more than six years before the filing of the complaint or counterclaim for infringement (35 U.S.C. 286)¹⁹.
In exceptional cases the court may award reasonable attorney fees to the prevailing party (35 U.S.C. 285)¹¹.

Europe

The Unified Patent Court (UPC) has exclusive competence over, among other actions, actions for actual or threatened infringements of patents, actions for declarations of non-infringement, actions for provisional and protective measures and injunctions, and actions for revocation of patents (Article 32(1) UPC Agreement)¹². See Unified Patent Court.
National courts of the contracting member states remain competent for actions relating to patents that do not come within the exclusive competence of the UPC (Article 32(2))¹².
During a transitional period of seven years after the Agreement entered into force, an action for infringement or for revocation of a European patent may still be brought before national courts or other competent national authorities (Article 83(1))¹³.
Unless an action has already been brought before the UPC, the proprietor of or applicant for a European patent can opt out from the exclusive competence of the UPC by notifying the Registry. The opt-out takes effect upon its entry into the register (Article 83(3))¹³.

China

A dispute over use of a patent without the patentee's authorization is to be resolved through consultation. If the parties are unwilling to consult or consultation fails, the patentee or any interested party may file a lawsuit in the people's court, or request the departments in charge of patent-related work to deal with the dispute (Patent Law, Article 65)¹⁴.
Compensation is determined on the basis of the right holder's actual losses or the infringer's profits, or, where these are hard to determine, by reference to a multiple of the patent licence royalty. For intentional infringement, if the circumstances are serious, it may be set at one to five times the amount so determined. Where none of these can be determined, the court may set compensation of RMB 30,000 to 5,000,000 (Article 71)¹⁴.
Validity is challenged separately: any entity or individual that considers the grant not in conformity with the Patent Law may request the patent administration department under the State Council to declare the patent right invalid (Article 45)¹⁴.

Court, ITC and PTAB routes in the US

A US infringement case in a district court is not the only US forum in which a patent is enforced or challenged. The table compares three, each with its own conditions.

Route	Who decides	What the law provides	Condition
District court	A federal district court³	Injunction in accordance with the principles of equity, damages of no less than a reasonable royalty, and attorney fees in exceptional cases^9,10,11	Infringement of a patent during its term²; except as otherwise provided by law, no recovery for infringement committed more than six years before the complaint or counterclaim (35 U.S.C. 286)¹⁹
ITC investigation (19 U.S.C. 1337)	The US International Trade Commission¹⁵	Exclusion of the articles concerned from entry into the United States, unless the Commission finds after weighing public health and welfare, competitive conditions, domestic production and consumers that they should not be excluded¹⁵. A determination can be disapproved by the President for policy reasons¹⁵.	Importation, sale for importation or sale after importation of articles that infringe a valid and enforceable US patent, and a US industry relating to the articles protected by the patent exists or is in the process of being established¹⁵
Inter partes review	The USPTO Director decides institution; a three-member PTAB panel conducts the trial^5,20	Review of the patentability of one or more claims in a patent⁵	Only on grounds under 35 U.S.C. 102 or 103 and only on patents or printed publications⁵. Not instituted if the petition is filed more than 1 year after the petitioner, real party in interest or privy is served with a complaint alleging infringement of the patent (35 U.S.C. 315(b))¹⁶

The burden of proof differs between court and inter partes review. In court, an invalidity defense must be proved by clear and convincing evidence¹⁷. In an inter partes review, the petitioner has the burden of proving unpatentability by a preponderance of the evidence (35 U.S.C. 316(e))¹⁸.

Seen in the record

The decision below is the US Supreme Court's ruling on where a patent infringement suit may be brought. It is an example of how venue rules are applied in US patent litigation, and says nothing about either party beyond the decision itself.

US Supreme CourtOpinion

TC Heartland LLC v. Kraft Foods Group Brands LLC

No. 16-3412017

Decided May 22, 2017. The Court held that, as applied to domestic corporations, residence in 28 U.S.C. 1400(b) refers only to the State of incorporation, and reversed and remanded the Federal Circuit's judgment 8.

Read the holding on patent venue.Open the record →

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Questions people ask

Which US court hears a patent infringement case?

A federal district court. The district courts have original jurisdiction of civil actions arising under the patent laws, and no State court has jurisdiction over a claim for relief arising under them³. The action may be brought where the defendant resides, or where it has committed acts of infringement and has a regular and established place of business⁷. For a domestic corporation, residence means its State of incorporation⁸. Appeals go to the Federal Circuit⁴.

Can a court decide whether a patent is valid?

In the US, yes: invalidity is a defense that must be pleaded in an action involving the validity or infringement of a patent¹. A patent is presumed valid, and the party asserting invalidity bears the burden¹, which must be met by clear and convincing evidence¹⁷. A separate route is inter partes review, where the standard is a preponderance of the evidence¹⁸. See Invalidity search.

Is there a single court for patent cases in Europe?

Not for every case. The UPC has exclusive competence over the actions listed in Article 32(1) of its Agreement¹². But for seven years after entry into force, infringement and revocation actions on European patents may still be brought before national courts¹³, and a proprietor can opt out of the UPC's exclusive competence unless an action has already been brought before it¹³.

What can a US court order against an infringer?

It may grant an injunction in accordance with the principles of equity⁹, award damages of no less than a reasonable royalty and increase them up to three times¹⁰, and in exceptional cases award attorney fees to the prevailing party¹¹.

How it connects

Builds onPatent claim

Done withClaim construction Invalidity search Doctrine of equivalents

Leads toWillful infringement Unified Patent Court Litigation funding

Often confused withInter partes review

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