An anti-suit injunction is a court order that prohibits a party involved in litigation from either transferring that litigation to another court, or filing an identical lawsuit elsewhere. When a court issues an anti-suit injunction, it is essentially saying that it will be the only court to decide the outcome of the case at hand. Most of the time, anti-suit injunctions are used to prohibit parallel foreign actions, but they can also be used to limit a party’s ability to re-file the same claims in a different domestic court.
In the most basic sense, an anti-suit injunction is a means of stopping lawsuits. It is generally not advantageous to a uniform body of law for a case to be tried in multiple forums simultaneously. If the courts come up with different results, or award different amounts of damages, it can be difficult to know which rulings are binding. Most of the time, the court where an action is first filed is the court with exclusive jurisdiction. A party who tries to file again elsewhere once things have gotten underway may find himself served with an anti-suit injunction.
Anti-suit injunctions are also a way for the courts to prohibit a practice known as “forum shopping.” Forum shopping happens when a plaintiff files a lawsuit in a particular court not because that court is most convenient or because it has primary jurisdiction over the issues and facts, but rather because it is more likely to issue a favorable ruling. This likelihood is often based on a judge’s statistics when ruling on a certain type of case, or on the demographics of local residents who might make up a jury.
Some forum shopping happens in most places at the filing stage. Anti-suit injunctions cannot do much about that. Once a lawsuit is filed and litigation starts, however, the injunction prohibits a party from changing his mind, or from trying to get a better result from an alternate court.
Most anti-suit injunctions occur in international disputes. It is rare for a court to take up a case that is contemporaneously being litigated in another national court — most of the time, duplicate litigation is a major violation of law and court rules. A court in one country might unknowingly accept a case that is also being litigated abroad, however. An anti-suit injunction can stop this sort of forum-shopping, often even before it has begun. Stopping litigation abroad is one of the most common types of anti-suit injunction.
Courts in different jurisdictions have different stances on when it is appropriate to issue an anti-suit injunction. The majority of courts have adopted what is known as a “restrictive” approach, and will only interfere in parallel filings when there is clear evidence of frustration of justice, or comity laws and other international laws explicitly permit the interference. A “permissive” approach, on the other hand, instructs courts to intervene and issue an injunction whenever the court subjectively believes it to be warranted.
In any case, parties who defy anti-suit injunctions can be subject to steep penalties in most places. Some courts will enter default judgment against parties who violate the order and pursue litigation elsewhere. Others will subject violators to contempt of court charges and fines.