It’s beneficial regarding both preparing for the trial and so each party can be adequately advised on its prospects of success. Below, we set out how an affidavit works as well as how the rules of evidence apply.

Relevant Evidence

In the same way that parties can only give evidence relating to a matter in court, an affidavit should only include relevant evidence. Failure to do so can see a court strike out parts of an affidavit, or deem the entire affidavit inadmissible. Additionally, outrageous or scandalous assertions contained in an affidavit are not admissible as evidence.

The person who is making the affidavit to include relevant evidence is called the deponent. This could be a witness, an expert, a plaintiff or defendant.

First Hand Knowledge 

As a general rule of evidence, a witness (referred to as the ‘deponent’ in an affidavit) can only give evidence of matters that are within that person’s first-hand knowledge. This usually means that a person can only give evidence of what he/she has seen, heard, smelled, felt or tasted. In a wider sense, a person can naturally provide evidence as to actions he/she has taken and what that person was thinking at that time (i.e. intention).

If a person gives evidence as to what another person told him or her about the incident, this is known as ‘hearsay’ evidence. Hearsay evidence is subject to detailed rules which will determine whether or not it is admissible under a specific circumstance.

Affirming an Affidavit 

A crucial part of the process of giving evidence in affidavit form is to ensure that it is properly witnessed. In other words, for the purpose of being admitted as evidence in court, it is vital that the contents of an affidavit were sworn (or affirmed) as being ‘true and correct in every particular’ in front of an authorised witness. Authorised witnesses are typically court registrars, lawyers, justices of the peace, police officers above the rank of sergeant and public notaries.

After an affidavit is sworn or affirmed, it can be filed and served where ordered to do so by the court.

Annexures and Exhibits 

Documents referred to in an affidavit are called either annexures or exhibits (depending on the specific court) and must be attached to the affidavit. The person witnessing the affidavit must attest to the fact that the documents attached to the affidavit are those referred to therein. 

The deponent and the witness should sign at the bottom of each page of the affidavit so that the intended contents of an affidavit cannot later be debated. Likewise, any handwritten changes to a typed affidavit must be initialled by the deponent and the witness before the oath or affirmation is administered and the affidavit is signed and witnessed.

You should seek legal advice if you are unsure whether to include something or not in an affidavit or as an annexure or exhibit.

Does This Mean I Don’t Need to Go to Court?

Even though a person has filed an affidavit containing his or her evidence in a case, they are still likely required to give evidence at the trial. The reason for this is two-fold. Firstly, it is important for the person to verify in court that he/she did indeed swear or affirm an affidavit in the case and that it is still true and correct as at the date of trial. Secondly, the other party may wish to cross-examine the witness (i.e. ask its own questions) on his/her evidence so as to test whether the court should accept it.


If you require assistance preparing an affidavit or at hearing or trial, get in touch with our specialist disputes lawyers on 1300 544 755 or fill out the form on this page.

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