Notary Public vs Commissioner of Oaths Explained
You need a document officially witnessed and authenticated, and you've been told you need either a notary public or a commissioner of oaths. The problem? Nobody explained the difference, and using the wrong one can result in your document being rejected, your application delayed, or your legal matter complicated. In Ontario, both notaries public and commissioners of oaths serve important — but distinct — functions. Understanding the difference isn't just academic; it's the difference between a document that works and one that doesn't. This guide breaks it down clearly.
The Short Answer
A notary public can do everything a commissioner of oaths can do — plus significantly more. A commissioner of oaths can only administer oaths and take sworn statements (affidavits and declarations). If you need anything beyond an administered oath or sworn declaration — certified copies, authentication for international use, witnessing legal contracts, preparing legal instruments — you need a notary public.
Think of it this way: all notaries can act as commissioners of oaths, but not all commissioners of oaths can act as notaries.
What Is a Commissioner of Oaths in Ontario?
A commissioner of oaths is a person authorized by the provincial government to administer oaths and take statutory declarations and affidavits. In Ontario, commissioners are appointed under the Commissioners for Taking Affidavits Act.
Their authority is limited to:
- Administering oaths and affirmations
- Taking and receiving affidavits
- Taking and receiving statutory declarations
- Signing documents that specifically call for a 'commissioner of oaths' rather than a notary
What a Commissioner of Oaths CANNOT Do
This is where the critical limitations appear. A commissioner of oaths in Ontario cannot:
- Certify true copies of documents
- Authenticate documents for use outside Ontario or outside Canada
- Prepare or certify powers of attorney for use internationally
- Issue notarial certificates
- Perform apostille-related services
- Certify documents for embassies or foreign governments
- Authenticate corporate or commercial documents for international use
What Is a Notary Public in Ontario?
A notary public in Ontario is a higher-level legal officer licensed by the Law Society of Ontario. Notaries have broader authority than commissioners and can perform all notarial acts recognized under provincial and international law.
Their authority includes everything a commissioner can do, plus:
- Certifying true copies of original documents
- Preparing notarial certificates for domestic and international use
- Witnessing and authenticating signatures on legal contracts and instruments
- Preparing and certifying powers of attorney
- Facilitating apostille and government authentication of documents
- Certifying documents for embassies, consulates, and foreign governments
- Preparing and certifying corporate documents
- Notarizing documents for real estate transactions
When Do You Need a Notary vs. a Commissioner in Ontario?
Use this breakdown to determine which officer you need:
- Swearing an affidavit for an Ontario court → Commissioner of oaths (or notary)
- Making a statutory declaration for an Ontario government form → Commissioner of oaths (or notary)
- Certified copy of a passport for an IRCC application → Notary public
- Document being sent to a foreign embassy or government → Notary public
- Power of attorney for use outside Ontario → Notary public
- Apostille or authentication for international use → Notary public
- Consent letter for child travelling abroad → Notary public (strongly recommended)
- Corporate resolution for a Canadian entity → Commissioner of oaths (or notary)
- Witnessing a real estate document → Notary public
Common Mistake: Using a Commissioner When You Need a Notary
This is one of the most common and costly errors in document preparation. A person has a document certified by a commissioner of oaths and submits it to a foreign embassy or institution — only to have it rejected because the institution required a notarial certificate, not merely a commissioner's oath.
Foreign embassies, international institutions, and organizations operating under the Hague Convention specifically require the seal and certificate of a licensed notary public. A commissioner of oaths stamp is not the same thing and will not be accepted as a substitute.
If your document is going anywhere outside Ontario — and especially outside Canada — always use a notary public.
Who Can Be a Commissioner of Oaths in Ontario?
In Ontario, many professionals are automatically commissioners of oaths by virtue of their position, including:
- Ontario lawyers and paralegals
- Municipal councillors and mayors
- Judges and justices of the peace
- Members of the provincial legislature
- Police officers
- Bank managers (for limited purposes)
- Persons specifically appointed by the government
Why Notary4u Uses Fully Licensed Notaries for All Services
At Notary4u, every service is performed by a licensed notary public in good standing with the Law Society of Ontario — not simply a commissioner of oaths. This ensures that every document we certify, witness, or authenticate meets the highest legal standard and will be accepted by Ontario courts, Canadian government institutions, foreign embassies, and international organizations.
We do not cut corners by offering commissioner-only services when a full notarial act is required. Our commitment is to documents that work — the first time, every time.
Frequently Asked Questions
Can a commissioner of oaths certify a copy of a passport in Ontario?
No. Certifying true copies is a notarial function. A commissioner of oaths does not have the authority to certify copies. You need a licensed notary public for this service.
Is a lawyer automatically a notary public in Ontario?
No. Ontario lawyers are automatically commissioners of oaths, but not automatically notaries public. Notary status requires a separate appointment or application through the Law Society of Ontario.
Can I use a commissioner of oaths for immigration documents?
It depends on the specific document. Statutory declarations required by IRCC may be accepted with a commissioner's oath. However, certified copies of documents for immigration purposes typically require a notary public. Check the specific IRCC requirement for each document.
Does Canada Post or a bank employee qualify as a commissioner of oaths?
Some bank managers are appointed as commissioners of oaths for limited purposes. Canada Post employees are not commissioners of oaths. For any legal document that will be submitted to government or used officially, use a licensed notary or a formally appointed commissioner.
How do I verify that a notary is licensed in Ontario?
You can verify a notary's licence through the Law Society of Ontario's online directory at lso.ca. All licensed lawyers and notaries in good standing are listed publicly.
Not sure whether you need a notary public or a commissioner of oaths? Notary4u's team will identify exactly what your document requires and ensure it's executed correctly — accepted by every institution, the first time.
