A Canadian Affidavit of Service is a formal sworn statement made by the person who served (delivered) legal documents on another party in a legal proceeding. The affiant, also known as the server, provides a detailed account of how, when, where, and upon whom the documents were served. This affidavit is filed with the court to prove that proper service was effected in accordance with the applicable provincial Rules of Civil Procedure and the Canada Evidence Act (R.S.C. 1985, c. C-5).

In Canadian legal practice, proof of service is a fundamental procedural requirement. Courts will not proceed with a hearing or motion unless the opposing party has been properly served, and the Affidavit of Service provides that proof. The document must be sworn or affirmed before a Commissioner for Taking Affidavits, a notary public, or a lawyer authorized to administer oaths in the relevant province. Making a false statement in a sworn affidavit constitutes perjury under section 131 of the Criminal Code of Canada (R.S.C. 1985, c. C-46), which carries a maximum penalty of fourteen years imprisonment.

Each province has its own rules governing service of documents. In Ontario, the Rules of Civil Procedure (R.R.O. 1990, Reg. 194) set out detailed requirements under Rules 16.01 through 16.09, including requirements for personal service, alternatives to personal service, and substituted service. British Columbia's Supreme Court Civil Rules (B.C. Reg. 168/2009) address service under Rule 4-3. Alberta's Alberta Rules of Court (Alta. Reg. 124/2010) cover service requirements in Part 11. Quebec follows its own Code of Civil Procedure (CQLR c. C-25.01), which uses the term "notification" rather than "service" and permits service by bailiff (huissier de justice).

A Canadian Affidavit of Service is required whenever a party to a legal proceeding needs to demonstrate to the court that documents have been properly served on another party. This is a mandatory step in virtually all civil litigation across Canadian provinces and territories. Without proper proof of service, a court will generally not grant default judgment, hear a motion, or proceed with a trial.

The Affidavit of Service is typically needed after serving originating processes such as a Statement of Claim (Ontario), a Notice of Civil Claim (British Columbia), or a Statement of Claim (Alberta). It is also required when serving motions, applications, affidavits, orders, subpoenas, and any other court documents that require formal service under the applicable Rules of Civil Procedure. In family law proceedings, service of applications, financial statements, and parenting orders also requires proof of service.

The affidavit must be prepared promptly after service is effected. In many jurisdictions, the affidavit must be filed with the court before the return date of a motion or before the deadline for the recipient to file a defence. For example, in Ontario, a defendant generally has 20 days after service of the Statement of Claim to file a Statement of Defence (Rule 18.01), and the plaintiff must file the Affidavit of Service to prove the clock has started running. Delays in preparing or filing the Affidavit of Service can result in adjournments or challenges to the validity of service.

A properly drafted Canadian Affidavit of Service must include several critical elements to satisfy the requirements of the applicable provincial Rules of Civil Procedure. The affidavit must begin with the jurisdiction information, identifying the province or territory and the municipality where the affidavit is being sworn. The affiant must be clearly identified by full legal name and residential address, and must state that they are of legal age (18 or older in all provinces) and are not a party to the proceeding.

The body of the affidavit must provide specific details about the service: the exact date and time of service, the precise location where service occurred, the full legal name and address of the person served, a complete list of all documents served, and whether originals or copies were delivered. The method of service must be described, such as personal service (physically handing the documents to the recipient), service by registered or regular mail through Canada Post, courier delivery (Purolator, FedEx, UPS), or substituted service as ordered by the court.

If service was effected by mail, the affidavit should include the tracking number and the name of the carrier. Under Ontario's Rules of Civil Procedure (Rule 16.03), service by mail is deemed effective on the fifth day after mailing. In British Columbia, service by ordinary mail is effective 14 days after mailing (Supreme Court Civil Rules, Rule 4-6). The affiant must swear or affirm the truthfulness of the statements under oath before a Commissioner for Taking Affidavits, a notary public, or a lawyer. The commissioner must sign and seal the affidavit. The document should conclude with a statement referencing the governing provincial law and the Canada Evidence Act.