Notary Public vs. Commissioner of Oaths in Ontario: Which One Do You Need?

If someone has asked you to get a document "notarized" or "commissioned," it's easy to assume they mean the same thing. They don't. A notary public and a commissioner of oaths have different powers in Ontario, and using the wrong one can mean your document is rejected — costing you a second appointment, or worse, a missed deadline.

The short answer: A notary public has broad authority — they can certify true copies, witness signatures, and notarize documents for use abroad. A commissioner of oaths is more limited — they can only administer oaths and take affidavits and statutory declarations for use within Ontario and Canada. If your document is going internationally or needs a certified true copy, you need a notary.

#What is a notary public in Ontario?

A notary public can certify and authenticate documents for use both in Canada and internationally. A notary can:

• Make certified true copies of original documents.
• Administer oaths and take affidavits.
• Witness signatures on documents.
• Perform other notarial acts required for legal or international purposes.

Importantly, in Ontario every licensed lawyer is automatically a notary public (and a commissioner of oaths). That means a lawyer-notary can handle the full range of notarial work in one appointment.

#What is a commissioner of oaths in Ontario?

A commissioner of oaths — also called a commissioner for taking affidavits — has a narrower role. A commissioner can:

• Administer oaths.
• Take affidavits and statutory declarations for use within Ontario and Canada.

A commissioner cannot certify true copies, and cannot notarize documents for international use. Their authority is limited to swearing or witnessing affidavits and declarations that will be used domestically.

#What is the difference between a notary and a commissioner?

The core difference is scope. A notary's authority is broader; a commissioner's is limited to domestic affidavits and declarations. Here's how they compare side by side:

Because every lawyer in Ontario is both, a lawyer-notary can do everything in the commissioner column and everything in the notary column.

#Which one do I need?

It comes down to what you're doing with the document:

• Need a certified true copy of a passport, diploma, or piece of ID? → You need a notary.
• Document going abroad or needing an apostille? → You need a notary.
• Sworn affidavit or statutory declaration for an Ontario court or a government form? → A commissioner can do this (and so can a notary).
• Not sure? → A lawyer-notary covers both, so you won't be turned away for bringing the wrong official.

#What are the most common documents people get notarized or commissioned?

A few situations come up again and again, and knowing which official handles them saves a wasted trip:

• Travel consent letters for minors — when a child travels with only one parent, a guardian, or alone, a consent letter signed in front of a notary (or commissioner) is widely requested by airlines and border officials. Because the document may be reviewed abroad, this is usually notary territory.
• Certified copies of ID and credentials — passports, driver's licences, diplomas, transcripts, and professional certificates often need to be submitted as certified true copies rather than originals. Only a notary can certify these.
• Affidavits and statutory declarations — sworn statements for an Ontario court, a name change, an insurance claim, or a government form. A commissioner of oaths is enough here, and a notary can do them too.
• Business and corporate documents — board resolutions, certificates of incumbency, and other records that need to be certified or notarized for use in another province or country.
• Documents bound for another country — anything going abroad for immigration, property, education, or family matters typically needs notarization, and often an apostille on top.

If your document falls in the first two or the last category, you almost certainly need a notary rather than a commissioner.

#Do I have to attend in person?

Yes. For both a notary and a commissioner, you generally must attend in person with:

• The original document (often unsigned, so it can be signed in front of the official).
• Valid government-issued photo ID.

The signing or swearing must happen in front of the official. Certified true copies cannot be done over video — the official has to physically compare the copy to the original document to certify it as a true copy.

#What about documents going to another country — and apostilles?

Since January 11, 2024, Canada is part of the Hague Apostille Convention. This changed how documents are prepared for use abroad.

For a document being used in a member country, after it's notarized you'll now typically need an apostille from Ontario's Official Document Services (ODS). The apostille is a standardized certificate that confirms the document's authenticity for international use. It replaced the older authentication-and-legalization process for countries that belong to the Convention.

In practice, that means international documents are usually a two-step process: notarize first, then obtain the apostille. A lawyer-notary can prepare the document correctly so it's ready for the apostille stage.

#Why use a lawyer-notary instead of a walk-in notary shop?

Walk-in notary services can stamp a document, but they often can't advise you on whether it's the right document, whether it's properly drafted, or what the receiving party actually requires. A lawyer-notary brings legal training to the table — they can spot a problem before it costs you a rejected filing or a failed apostille, and they can advise on the underlying matter, not just witness a signature.

At Tokas Lex you get a lawyer who is both a notary public and a commissioner of oaths, so whatever your document needs — a certified true copy, a sworn affidavit, a travel consent letter, or a document bound for another country — it's handled correctly the first time. (Buying a condo and need documents reviewed too? See our guide to the condo status certificate in Ontario.)

If you're not sure which official your document requires, contact Tokas Lex and we'll point you in the right direction before you book.

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This article provides general information about Ontario law and notarial services and is not legal advice. Requirements vary by document and by the authority that will receive it. For your specific situation, please consult a lawyer.