Anti-Suit Injunctions in Global SEP Disputes 

Need to know

In standard essential patent disputes that spread across multiple forums, anti-suit injunctions and similar cross-border remedies are important tools for strategic case management. Parties should treat such remedies as part of a unified global litigation strategy, plan for their use early, and align fair, reasonable, and non-discriminatory negotiation records with enforcement or defense strategies.  

Standard essential patent (SEP) disputes routinely involve worldwide patent portfolios and span multiple jurisdictions, while patent rights remain territorial. Jurisdictional differences can create scenarios in which one court is asked to decide patent infringement, validity, or injunctive relief, while another is asked to resolve fair, reasonable, and non-discriminatory (FRAND) licensing terms for the same patents. For example, a patent owner may sue for infringement in Europe at the Unified Patent Court (UPC), an implementer may ask a U.K. court to set global FRAND terms, and a U.S. court may be asked to decide antitrust issues involving the same accused technology. These cases may proceed in parallel, and each forum may have a different view of how the parties should resolve the dispute globally.

That is where an anti-suit injunction (ASI) and related remedies may come in. These remedies can determine whether a party may continue a foreign case, enforce a foreign injunction, or ask another court for relief that affects the dispute elsewhere. Companies involved in SEP licensing should consider these remedies together with forum and FRAND strategies.  

Understanding ASIs, AASIs, and related orders

An ASI is an order directing a party not to file, continue, or enforce litigation in another forum. In SEP disputes, implementers often seek ASIs to stop patent owners from pursuing foreign infringement actions or injunctions while FRAND disputes are pending in other forums.

An anti-anti-suit injunction (AASI) is the mirror-image response. It prevents a party from seeking or enforcing an ASI that would interfere with the court’s proceedings. Patent owners often seek AASIs to preserve their ability to enforce patents in particular jurisdictions.

There are also other less common but no less powerful cross-border remedies. An anti-enforcement injunction (AEI) may stop a party from enforcing a judgment or injunction from another court. An anti-interference injunction (AII) may stop a party from asking another court for relief that would interfere with the case already pending before the issuing court. Recent SEP disputes have also involved interim license requests, in which a party asks for temporary license terms while final FRAND terms are being decided, and the mirror-image anti-interim-license injunction (AILI), which is aimed at preventing a party from seeking such an interim license. 

Why SEP disputes create forum pressure  

SEP cases are especially prone to forum fights because they involve global patent portfolios, worldwide licensing practices, and jurisdiction-specific enforcement. For example, a smartphone or network device may be sold around the world and practice the same standard everywhere, but SEP infringement and validity are decided on country-by-country basis.  

SEP owners usually prefer to enforce patents in jurisdictions where injunctive relief is fast and meaningful. Implementers may prefer forums that will set global FRAND terms or reduce the threat of foreign injunctions. ASIs, AASIs, and related orders arise when those strategies collide.

How the major forums differ

In the U.S., ASIs are available, but courts usually treat them as extraordinary relief. U.S. courts look closely at comity, the overlap of issues between the U.S. and foreign cases, and whether the U.S. proceeding can resolve the foreign injunction issue. In practice, the U.S. is an important forum for parties seeking to manage foreign injunction pressure in global SEP disputes, especially where foreign proceedings may affect U.S. patent rights or U.S. FRAND issues.

The U.K. plays a significant role in global SEP litigation because U.K. courts have set global FRAND terms in appropriate cases. Recently, the U.K. has become a key forum for interim-license issues. Interim licenses do not stop foreign cases the same way ASIs do, but they can have ASI-like effects because they set interim global FRAND terms that may reduce pressure from parallel foreign proceedings.

Germany remains one of the most important patent enforcement forums. SEP owners often value Germany because German courts generally move efficiently and have a significant history of AASI practice designed to protect local patent enforcement proceedings. They have also reacted to interim licenses originating from other jurisdictions and may issue AILIs to stop parties from affecting German enforcement.

The UPC is growing in prominence within the broader European patent enforcement landscape. Unlike national courts, the UPC can provide relief across participating UPC member states, although its SEP case law is still developing. Recent practice suggests that the UPC is prepared to protect its own proceedings from foreign orders that could interfere with patent enforcement. The UPC has already issued AASI and AILI decisions, suggesting a willingness to use protective cross-border remedies familiar from German national practice.

China is a critical forum because its courts hear FRAND rate-setting disputes involving global SEP portfolios. China’s earlier use of ASIs drew significant international scrutiny, but the landscape changed after a World Trade Organization (WTO) ruling (DS611) found China’s ASI policy inconsistent with the Agreement on Trade-Related Aspects of Intellectual Property Rights.  In response, China announced the withdrawal of its ASI policy. Nevertheless, Chinese courts continue to assert jurisdiction over worldwide FRAND licensing rates, and this practice is currently being challenged in a separate WTO dispute (DS632). China therefore remains strategically important for SEP disputes even though its cross-border SEP practice is evolving.

Advice for practitioners

In global SEP and FRAND disputes, a single cross-border injunction can reshape an entire dispute. The location of the first-filed action can determine which defensive options remain available, including ASIs, AASIs, and related remedies.

Counsel should expect ASIs, AASIs, and similar relief to move quickly. A filing in one country can trigger emergency papers in another within days. Courts often consider these requests on compressed timelines. Early planning is therefore crucial.

Counsel should also prepare FRAND negotiation correspondence with the understanding that it may surface in proceedings in several countries. The same FRAND correspondence may support or undermine arguments about willingness, delay, good faith, or commercial harm, depending on the country of the litigation.