What Is an Affidavit?

Affidavits set out the facts a party wishes the court to consider. They may be filed in support of an application, in response to one, or as the principal evidence at a hearing. In many civil disputes, the parties exchange affidavits in advance of the hearing so that everyone knows what evidence will be relied on.

An affidavit becomes legally binding when the maker swears, on a religious text, or affirms, without religious content, that its contents are true. Both have the same legal effect. The act of swearing or affirming is done in the presence of an authorised person, usually a solicitor, justice of the peace or notary public.

An affidavit follows a recognisable structure. It identifies the court and parties, names the deponent and gives their occupation and address, and sets out the evidence in numbered paragraphs written in the first person. Documents referred to in the affidavit are attached as exhibits and identified by a certificate signed by the witnessing person.

An affidavit should set out facts within the deponent's personal knowledge, not opinions or argument. Where the deponent is repeating something they were told, they must say who told them and when. Hearsay and opinion are sometimes admissible in interlocutory applications but rarely at final hearings, where the rules of evidence apply more strictly.

Filing an affidavit usually means the deponent can be called for cross-examination at the hearing. Anything in the affidavit may be tested, so accuracy and care matter. A statement made in an affidavit that turns out to be false can expose the deponent to serious consequences, including a charge of perjury.

Most affidavits used in court are prepared with the help of a solicitor. They will work with the deponent to ensure the evidence is complete, properly structured and admissible. Investing time at the drafting stage almost always pays off when the matter is heard.