Australian citizens are required by law to file a tax return once a year with the Australian Taxation Office. You can choose to file a return by mail or on the Internet. If you want to use the Australian government's e-file service, you must have a sequence number. A sequence number is a unique identifier that you can use to lodge your tax return online. If you've lost your sequence number, you'll need to recover it before you can file a return.
Find any notices of assessment you have received from the Australian government within the last five years. These notices are sent to you once a year, after you have filed your tax return.
Look on the notices for the sequence number. It is found at the top right, under the date of issue.
Call the Australian Taxation Office at 13 28 65 for assistance if you can't find the notices. The lines are open 8 a.m. to 6 p.m., Monday through Friday.
