Are you looking to start a new business? Make sure you know the difference between an ABN and an ACN to ensure that you have registered your new business or company properly.  


What is an ABN? 

An Australian Business Number, commonly referred to as an ABN is an eleven-digit number that all businesses must acquire. It uniquely identifies the business and is used in commercial dealings and transactions with the Australian Taxation Office (ATO), customers, and other businesses.  


When and how can I apply for an ABN? 

Not everyone requires an ABN. It is only necessary if you are operating a business. To apply for an ABN, you can use the Business Registration Service, which also allows you to register a business name simultaneously.  


What is an ACN? 

An Australian Company Number (ACN) is similar to an ABN. However, it is a nine-digit number that uniquely identifies your company. While the ATO issues ABNs, the Australian Securities and Investments Commission (ASIC) issues ACNs.  

Not every business is a company, so a business might have only an ABN without needing an ACN. Conversely, a company might initially only have an ACN, but once it starts operating as a business, it must register for an ABN as well. 


When and how can I apply for an ACN? 

You can set up a company through the Business Registration Service. Once registered, you will automatically receive an ACN. You can choose to set up a company yourself through ASIC or ask a lawyer to assist you. 

Before setting up a company, it is important to check that your chosen company name is available by searching the register. Additionally, you must verify that no existing business names or trademarks are similar to your desired name, as this could restrict your ability to use it.  


Key takeaways 

  • Only companies are issued with an ACN, while an ABN is issued to a business. 
  • An ACN is a nine-digit number, while an ABN is an eleven-digit number. 
  • It is important to speak to a lawyer if you are unsure whether you need an ABN or ACN. 




 Gladwin Legal are experts in Commerical Law and have extensive experience in advising businesses. If you require assistance in understanding your legal obligations please contact us at or 1300 033 934.