Affidavit vs statutory declaration: the legal difference, when to use each, and what they have in common. A plain-English explainer for Ontario.
The short answer
An affidavit is a sworn or affirmed statement of fact, used most commonly in court proceedings. A statutory declaration is a solemn declaration of fact, used in non-court contexts under the Canada Evidence Act, RSC 1985, c C-5, s 41 (federal) or comparable provincial provisions. Both must be made before a person authorized to receive them (typically a commissioner for taking affidavits or a notary public in Ontario). Knowingly making a false statement in either may attract criminal liability under the Criminal Code, RSC 1985, c C-46 (for example, perjury under s 131 in the case of sworn evidence, and false statement offences under ss 134–138 more broadly).
Affidavits
Used in court proceedings, estate administration through probate court, and some regulatory tribunals. Form is usually prescribed: “I, [name], MAKE OATH AND SAY…” ending with the jurat (notary or commissioner’s confirmation that the oath was administered, date, signature, seal).
Statutory declarations
Used in non-court contexts: IRCC applications, common-law union declarations for insurance and pensions, lost-document declarations, declarations of identity or residency. Form is similar: “I, [name], DO SOLEMNLY DECLARE…”
Who can witness
Both can be commissioned by a commissioner for taking affidavits or by a notary public in Ontario. If the document is going outside Ontario, a notary is usually the safer choice because of the embossed seal.
What happens if you use the wrong one?
If you give a court a statutory declaration when an affidavit was required, the court may refuse it. If you give IRCC an affidavit when their form calls for a statutory declaration, they may ask you to redo it. Follow the recipient’s instructions exactly.
Frequently asked questions
Is one more “serious” than the other?
Both are formal legal statements, and knowingly making a false statement in either may attract criminal liability. The procedural distinction is the context in which each is used, not the relative seriousness of telling the truth.
Can I sign at home and bring it to the notary?
No. The notary or commissioner must see you sign and administer the oath or affirmation.
Does my religion affect whether I swear or affirm?
You choose. Both are legally equivalent in Ontario.