Subpoena Ad Testificandum (What is a Subpoena Testificandum)

You heard of the term subpoena ad testificandum and you wonder what it means!

What is the difference between a subpoena vs subpoena ad testificandum and how do you comply with it?

In this article, we will discuss this concept in detail so you will know all there is to know about it.

Let’s get started!

What is a subpoena ad testificandum

A subpoena ad testificandum is a type of subpoena that orders a person to appear at a designated location at a specific date and time and testify.

Most people refer to a subpoena ad testificandum as just “subpoena”.

When a person is served with a subpoena ad testificandum, that person is required to present himself or herself at a certain date, at a certain time and at a certain place to orally testify about facts they have personal knowledge of.

Purpose of a subpoena ad testificandum 

Fundamentally, for the court system to be able to effectively operate and render justice for the people, it must have the ability to compel witnesses to testify and be heard. 

The judicial system in a democratic society built on the rule of law, fairness and equity must allow parties to a lawsuit to present their case including the oral hearing of fact witnesses. 

The law has given the courts authority and power to compel a person to testify and act as a witness regardless of the person’s willingness to testify or not. 

The powers given to the courts to issue a subpoena goes to the heart of the proper functioning of the judicial system and a person’s right to be fully heard so justice can be rendered.

A subpoena ad testificandum is the legal mechanism allowing a party or the court to bring those individuals they feel have personal information valuable for a court to consider when rendering a judgment.

Who can issue a subpoena ad testificandum

Depending on your jurisdiction, a subpoena ad testificandum can be issued by many authorized bodies such as a court, grand jury, legislative body or administrative agency.

In certain jurisdictions, a subpoena ad testificandum can only be issued by a lawyer, a judge or a court clerk.

When a subpoena is validly issued, the person receiving it must comply with it and show up to testify as a witness.

When do we use a subpoena testificandum 

A subpoena testificandum is commonly used in the context of legal proceedings.

For the courts to render a judgment in a lawsuit, they need to hear all relevant witnesses involved to get a full and complete picture of the facts.

A subpoena testificandum is therefore used to compel a third-party to act as a witness in a case or to have them testify in the context of a deposition. 

The subpoena can be sent to someone to testify before a judge during trial or to give a deposition.

A deposition is an out-of-court examination where the witness’s testimony is under oath and recorded verbatim by a court reporter.

How do you comply with a subpoena ad testificandum

The compliance with the subpoena ad testificandum is not difficult in itself.

All you need to do is to appear where you are asked to testify, on the given date and time.

When you go to court, you will be called to testify in front of a judge and answer questions the lawyers will ask you about a case.

Depending on the nature of the case wherein you are being asked to testify, you may want to know more about your rights and obligations by consulting a litigation lawyer.

You want to make sure that you are not going to be asked questions where you reveal information that could be damaging to you or forcing you to reveal privileged information for example.

What is the penalty for not respecting a subpoena ad testificandum 

Just like for any other type of subpoena, if you do not respect the order of the subpoena, you can put yourself in contempt of court.

Contempt of court is when you are deliberately disobeying or disrespecting the court’s judgment or deliberately fail to respect its orders.

When a witness receives a subpoena requiring it to testify in court and fails to do so, in many jurisdictions the court has the power to issue an arrest warrant to have the person brought before a judge.

The court can condemn the witness to pay for all the costs associated with its failure to present himself or herself to court to testify.

In many jurisdictions, failing to comply with a subpoena can result in severe fines or even imprisonment.

Is it mandatory to send a subpoena ad testificandum

It’s not mandatory to send a subpoena ad testificandum for someone to come and testify if they inform you that they will voluntarily do it.

In case you are dealing with a witness clearly refusing to testify and not collaborating, then a subpoena will be quite useful.

When the witness is served with a subpoena, he or she will no longer have a choice but to testify.

Failure to testify can result in a condemnation for contempt of court, fines and even imprisonment.  


A subpoena ad testificandum is a type of subpoena requiring someone to show up to court and testify.

It can even be for a deposition.

Often, we don’t say “subpoena ad testificandum”, rather, we’ll use the term “subpoena” to refer to it.

Subpoenas are sent to individuals and entities quite regularly in the context of legal proceedings.

Using a subpoena ad testificandum, parties to a case can ensure they can bring people and fact witnesses before the court so they can give an account of facts and information they have personal knowledge of.

We hope you enjoyed this article helping you clarify the concept of subpoena ad testificandum.

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