You can update your client's details online via Tax professionals services or by contacting the ABR. If their business structure changes their ABN may need to be cancelled.
It is your client’s responsibility to maintain their ABN details. The ABR must be notified within 28 days of becoming aware of changes.
It is important that ABN details are kept up-to-date. The fastest way to cancel your client's ABN is online with AUSkey.
If your client's business structure changes, they may need to cancel their ABN and apply for a new one.