What Does an Injunction Do? Types, Proof, and Violations

An injunction is a court order that either compels someone to do a specific thing or forbids them from doing it, and courts issue one when money alone cannot fix the harm at issue. So what does an injunction do in practical terms? It changes behavior under threat of the court’s contempt power: a party bound by the order who ignores it can face fines, jail, or both. Injunctions come in emergency, interim, and final forms, and getting one requires meeting a demanding four-part test.

What an Injunction Actually Does

Every injunction either tells someone to stop or tells someone to act. A prohibitory injunction, the more common form, orders a party to cease a specific activity. A court might bar a company from using a patented design, stop a former employee from sharing confidential business information, or halt construction that would destroy a protected building.

A mandatory injunction does the opposite. It orders a party to take affirmative action: tear down a fence built on a neighbor’s land, recall a dangerous product, or honor a contract term. Mandatory injunctions are harder to obtain. Courts are generally more comfortable telling people to stop than ordering them to act, but they are essential when the harm can only be undone by doing something rather than by ceasing to do something.

The Three Types by Timing

Beyond what they require, injunctions are classified by how long they last and when in a lawsuit they are issued. The three forms escalate from emergency measure to final judgment.

Temporary Restraining Orders

A temporary restraining order, or TRO, is the emergency version. When the situation is urgent enough — a company is about to destroy evidence, a developer is days away from demolishing a disputed building — a court can issue a TRO almost immediately. Under federal rules, a TRO can be granted without notifying the other side, but only if the person requesting it shows specific facts demonstrating immediate and irreparable harm and explains what efforts were made to give notice.¹ A TRO expires within 14 days unless the court extends it for good cause. It is meant purely as a stopgap until a proper hearing can be scheduled.

Preliminary Injunctions

A preliminary injunction picks up where a TRO leaves off, or serves as the first step when the situation is not so urgent that the other side cannot be notified first. Unlike a TRO, a preliminary injunction can only be granted after notice to the opposing party and a hearing where both sides present evidence and arguments.¹ Its purpose is to preserve the status quo while the lawsuit plays out, keeping either side from making the dispute worse before the court can fully resolve it. A preliminary injunction stays in effect until the court reaches a final decision.

Permanent Injunctions

A permanent injunction is issued at the end of a trial as part of the final judgment. The court has heard all the evidence, both sides have made their case, and the judge concludes that ongoing court-ordered relief is necessary. The Supreme Court established in eBay Inc. v. MercExchange that a permanent injunction requires the plaintiff to prove all four elements of the traditional equity test: irreparable injury, inadequacy of money damages, a balance of hardships favoring the plaintiff, and no harm to the public interest.² Despite the name, “permanent” does not always mean forever. The court can set a specific time period or conditions under which the order ends.

What You Have to Prove

Getting an injunction is not easy. Courts treat them as extraordinary relief, and the party asking carries a heavy burden. Whether you are seeking a preliminary or permanent injunction, you generally need to satisfy four requirements.

Irreparable harm. You must show that without the injunction, you will suffer harm that money cannot adequately fix. Losing a unique piece of property, having trade secrets exposed, or suffering ongoing damage to business reputation are the kinds of injuries courts consider irreparable. If a dollar amount could make you whole, the court will usually tell you to pursue damages instead.
Likelihood of success on the merits. You need to convince the court that your underlying legal claim is strong enough that you are likely to win at trial. A judge will not freeze someone’s activities based on a weak or speculative case.
Balance of hardships. The court weighs the harm you will suffer without the injunction against the burden the order would impose on the other side. If stopping the defendant’s activity would put them out of business while your harm is modest, the court may decline.
Public interest. The court considers whether granting the injunction would serve or harm the broader public. An injunction that shuts down a sole-source medical supplier during a shortage, for example, might fail this prong even if the other three are met.²

All four factors matter. Weakness on one can sink the request even if the other three are strong. The evidence supporting these factors is typically presented through sworn written statements, called affidavits or declarations, attached to a formal motion.

The Bond You May Have to Post

Something that catches many people off guard: getting an injunction usually requires putting up money. Under federal rules, a court can only issue a preliminary injunction or TRO if the party requesting it posts a security bond in an amount the court considers appropriate.¹ The bond exists to protect the other side. If it turns out the injunction was wrongly granted, the bond covers the costs and damages the restrained party suffered while the order was in effect.

The amount varies widely. A dispute over a garden fence might require a few thousand dollars; a case involving a major business operation could require hundreds of thousands. Bonds are typically obtained through a surety company, which charges a non-refundable premium, often a small percentage of the total bond amount. The federal government and its agencies are exempt from the bond requirement.¹ State courts have their own bond rules, and some allow judges to waive the bond in certain circumstances, such as when the party seeking the injunction cannot afford it.

Who the Order Binds

An injunction does not bind only the person named in the caption. Under federal rules, the order binds the parties to the case, their officers, agents, employees, and attorneys, along with anyone else who acts in concert with them and has actual notice of the order.¹ A company cannot dodge an injunction by having an employee or business partner do the prohibited act instead. If that person knows about the order and participates in violating it, they are on the hook too.

What Happens If Someone Violates It

Ignoring an injunction is one of the faster ways to make a legal situation dramatically worse. A person who knowingly violates the terms of an injunction can be held in contempt of court. Federal courts have the power to punish contempt through fines, imprisonment, or both.³

Contempt comes in two flavors, and the distinction matters. Civil contempt is coercive. Its purpose is to force compliance, not to punish. A judge might impose a daily fine that accumulates until the violator obeys the order, or even jail time that lasts until the person does what the court requires. The classic formulation is that the person carries the keys to their own prison: comply with the order, and the penalty ends immediately. The court can also order the violator to pay the other party’s attorney’s fees and costs incurred because of the violation.

Criminal contempt is punitive. It imposes a fixed fine or a set jail sentence to punish past disobedience and vindicate the court’s authority. Unlike civil contempt, the penalty does not go away when the person finally complies. It is punishment for having violated the order in the first place. Courts do not take kindly to having their orders ignored, and the penalties escalate quickly for repeat or willful violations.

1
Legal Information Institute. Federal Rules of Civil Procedure Rule 65 – Injunctions and Restraining Orders
2
Justia. eBay Inc v MercExchange LLC, 547 US 388 (2006)
3
Office of the Law Revision Counsel. 18 USC 401 – Power of Court