What Is a Subpoena?

A gavel on top of an open book that shows a rule concerning subpoena.


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In the American legal system, a subpoena is a written court order that requires the production of documents or court testimony. The term is Latin for "under penalty." A subpoena lists the name and address of the subject, the date and time of the appearance, and the request.

There are two distinct types of subpoenas: a subpoena ad testificandum for in-court testimony, and subpoena duces tecum for the production of materials relevant to the case (documents, records, or any other type of physical evidence).

Why Are Subpoenas Used?

During the “discovery” or fact-finding phase of a trial, attorneys use subpoenas to gather evidence or witness statements. Subpoenas compel individuals to provide evidence or testimony, which makes them extremely valuable tools for the justice system. Placing enforceable, legal requirements on the gathering of evidence helps both sides in a legal case gather as much evidence as possible to help the judge or jury reach a fair verdict. 

The two types of subpoenas are used for different reasons and to gain different types of information. For example, a subpoena duces tecum might compel a business to turn over records concerning an employee suspected of a crime. On the other hand, a subpoena ad testificandum might order someone to appear in court and testify about a suspect's location on the night that a crime occurred.

Anyone who fails to respond to a subpoena is held in contempt of court. Depending on the state, that individual may remain in contempt until they fulfill the terms of the subpoena. A contempt charge can result in fines or jail time. There are two types of contempt:

  • Civil contempt: An individual purposefully avoids the actions listed on the subpoena in an attempt to hinder the legal procedure.
  • Criminal contempt: An individual meaningfully disrupts the court, sometimes by being disrespectful while court is in session.

Who Is in Charge of Issuing Subpoenas?

Subpoenas may be issued on behalf of a court, a grand jury, a legislature, or an administrative agency. Subpoenas are signed and addressed by the issuer. They are often issued by an attorney if someone is being tried in a civil or criminal case. The issuer may be an administrative law judge if the subpoena compels a high ranking official to testify or produce physical evidence.

How Subpoenas Are Served

The subject of the subpoena must be served in order for them to appear in court. Though the legal requirement for service differs between states, the most common ways of serving a subpoena are in-person delivery or certified mail. Some states even allow subpoenas to be sent over email with an “acknowledgment of receipt” requested.

A server must be over 18 years old and have no involvement with the case. No matter how the document is served, the server must sign to legally show that they delivered the document. Occasionally, a subpoena may be served by a police officer. In some jurisdictions, a police officer will deliver a second subpoena if the first one is ignored, then escort the subpoenaed party to court to testify.

Subpoena vs. Summons

Subupoenas and summons are easy to confuse because a subpoena summons a person to court. However, summons are entirely separate documents in civil proceedings. Prior to the court date, the plaintiff in a civil case is required to serve the defendant with a summons: a formal notice of a lawsuit.

There are several key differences between a summons and a subpoena:

  • A subpoena is a legally binding order, whereas a summons is a notice of legal action.
  • Subpoenas are served during the discovery phase of the trial. A summons is a notice that signals that a complaint has been filed in a civil proceeding.
  • If someone ignores a summons, they are not subject to contempt of court like a subpoena and face no legal charges. Instead, they risk losing the lawsuit because the judge may find in favor of the plaintiff if the defense is not present in court.

Both a subpoena and a summons must be served. A summons can be served by a sheriff, a process server, or by certified mail. In most states, it must be served with a copy of the complaint. Just like a subpoena, a summons cannot be served by the issuer and must be served by someone over the age of 18.

Subpoena Key Takeaways

  • subpoena is a written court order that requires the production of documents or a court testimony.
  • During the “discovery” or fact-finding phase of a trial, attorneys use subpoenas to gather evidence or witness statements.
  • Subpoenas must be officially served, typically by in-person delivery or certified mail. 
  • Anyone who fails to respond to a subpoena may be held in contempt of court. 


  • “How Courts Work: Discovery.” American Bar Association, www.americanbar.org/groups/public_education/resources/law_related_education_network/how_courts_work/discovery.html.
  • “How Courts Work: Pre-Trial Procedures in Civil Cases.” American Bar Association, www.americanbar.org/groups/public_education/resources/law_related_education_network/how_courts_work/cases_pretrial.html.
  • “Serving the Papers.” MassLegalHelp, www.masslegalhelp.org/domestic-violence/wdwgfh12/serving-papers.
  • “Subpoena.” A Dictionary of Law, Edited by Jonathan Law, 8th ed., Oxford University Press, 2015.
  • "Subpoena." Britannica Academic, Encyclopædia Britannica, 9 Apr. 2018. Accessed 26 Jun. 2018.
  • “Subpoena.” LawBrain, lawbrain.com/wiki/Subpoena.
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Spitzer, Elianna. "What Is a Subpoena?" ThoughtCo, Aug. 27, 2020, thoughtco.com/subpoena-definition-uses-4171570. Spitzer, Elianna. (2020, August 27). What Is a Subpoena? Retrieved from https://www.thoughtco.com/subpoena-definition-uses-4171570 Spitzer, Elianna. "What Is a Subpoena?" ThoughtCo. https://www.thoughtco.com/subpoena-definition-uses-4171570 (accessed June 9, 2023).