What’s the difference between a notary public and a commissioner of oaths?
A commissioner of oaths (or a commissioner for oaths) is someone authorised by law to take oaths, affirmations, and declarations from people swearing to the truth of certain documents or for certifying true copies of documents for legal purposes. In New South Wales, this role is usually performed by a justice of the peace.
If you must sign a document that requires a ‘prescribed witness’ or you must certify a copy of your original document, then you can usually use a justice of the peace, a lawyer, or a notary public. However, if you have been told that your document must be signed in front of a commissioner of oaths, it is probably because your document will be used in another country (or in another state other than New South Wales) where they have commissioners of oaths. If your document is going to be used in another country, then your document will likely need to be notarised by a notary public instead of being attested by a commissioner of oaths, justice of the peace, or a lawyer (who is not a notary public).
In Australia, a notary public is a senior lawyer who has completed further qualifications to be appointed as a notary public. A notary public, like a commissioner of oaths, is authorised by law to take oaths, affirmations, and declarations from people swearing to the truth of certain documents or for certifying true copies of documents for legal purposes.
The important difference between a notary public from a justice of the peace, a commissioner of oaths, or any other prescribed witness is that if a document is intended to be used in another country then it should be notarised which can only be done by a notary public. On the other hand, if you are using your document in Australia, then you can use a justice of the peace.
If your document must also be stamped with an apostille or authenticated by the Department of Foreign Affairs and Trade (DFAT), then your document must be notarised by a notary public. DFAT will not recognise documents attested by a commissioner of oaths, justice of the peace, or a lawyer (who is not a notary public).
The fact that you are asking this question or searching for answers and you are now reading this page suggests that someone has asked you to use a commissioner of oaths or you are sending your documents overseas which means you will need to use a notary public to notarise your documents.
Who can witness my signature or certify my documents?
Other FAQs regarding our notary public services
If you have any other questions regarding our notary public services, please contact us or browse our other frequently asked questions:
- What’s a ‘notary public’?
- What does a notary public do?
- What’s the difference between a notary public and a justice of the peace?
- What’s the difference between a notary and a commissioner of oaths?
- What makes you different from other notaries?
- What’s an ‘apostille’?
- What’s the Apostille Convention?
- I’ve been told I need an apostille. Where and how do I get it?
- What’s ‘authentication’?
- Are you recognised by the Department of Foreign Affairs and Trade?
- What’s your experience in providing notary public services?
- Do you provide any services other than notary services?

Do you have any questions regarding this article?
Whether you’re notarising a document for the first time or the hundreth time, the requirements, processes, and terms can be confusing and daunting – or just a pain and a hassle (especially if you need an apostille, or to authenticate or legalise as well). Don’t worry! We’re here to simplify it, explain it, and help you with what you need to achieve it.
Contact us or visit our Frequently Asked Questions for more information about our notary public services. We’ve also created a flowchart to help explain notarisation, apostille, authentication and legalisation.
So, what’s next?
Visit our Notary Fees page for a free quote for our notary public services or just call us on +61 2 9687 8885 to speak with our friendly team about your requirements.
Why choose Phang Legal for your notary public services?
We’re a leading provider of notary public services in Sydney known for our experience and expertise in notarising documents for other countries, our low-cost fixed fees and service offering, and our availability to help on short notice. With our offices conveniently located in Parramatta, the geographic centre of the Sydney metropolitan area, we help clients from across Sydney and beyond with personal, professional and timely notary public services.

Notary Public
This website is maintained by Phang Legal, a boutique law firm in Parramatta and a leading provider of quality notary public services to satisfied clients across Sydney.
Ern Phang is a director of Phang Legal and a notary public (since 2005). Ern regularly writes about his experiences as a notary public and the issues faced by his clients in sending documents to other countries.