You may have cancelled your Australian Business Number (ABN) because you decided to stop trading, or because you sold your business, or for a range of other reasons. Australian law requires businesses to have an ABN to operate, and if you fail to reactivate it you may be liable for fines.
Checking ABN status
You should first check whether your ABN has indeed been cancelled. This can be done on the ABN lookup tool on the Australian Business Register (ABR). If the ABN is still active, you are required to update the details of your new business within 28 days.
Reactivating your ABN is done through the ABR website. It involves applying for a new ABN, and on the final step answering “yes” to “Have you had an ABN before?” and providing your details. Otherwise you will also need to provide general business information (name, contact number, business location etc.).
Fortunately, this process does not require any fee. However, if you wish to re-register your business name this will indeed cost money.
Your ABN should be reactivated within 24 hours. Use the ABN lookup tool mentioned above to check its status