An affidavit is a voluntarily made by an individual known as an affiant or deponent under an oath or affirmation. The contents of an affidavit reflect the personal knowledge of the individual making the statement. The mental capacity and comprehension of the statement by the affiant must be ascertained before the document can be signed. The affidavit is executed by the signature of the affiant and a witness who will authenticate the signature.
The authentication is usually carried out by a person authorised to do so by law such as a Notary Public, Solicitor or Commissioner for Oaths, along with identification and capacity checks before the document is signed. It is vital that the authorised person determines that the correct person is signing the document, and that this person has a full understanding of what they are signing before any action is taken to execute the document.
Following the signing of the document, the affiant will swear an oath according to their religion, or an affirmation if they do not follow a religion.
A Notary Public will be required if the affidavit is going to be used abroad. A Commissioner for Oaths can be used if the affidavit will be used solely in the United Kingdom. Requirements should be checked with the party who will receive the document.
When writing an affidavit, consideration should be given to having it professionally drafted. A standard affidavit will have numbered clauses that list as many of the facts that need to be stated as possible, along with a statement of truth, the oath or affirmation that needs to be sworn or affirmed, a signature clause for the person making the affidavit, and a signature clause for the witness/commissioner for oaths/notary public.
An affidavit does not have to have an expiration date, but will be disregarded as evidence if the facts contained within it are found to be false.