What is the difference between registering for an australia.gov.au account and registering for agency online services through australia.gov.au?

Registering for an australia.gov.au account will only provide you with an australia.gov.au account that is not linked to any agency online services.

You then need to link the account to participating agency online services by proving you own the agency record. Following these two steps registers you for an agency online account which uses your australia.gov.au account user ID and password for access.

If you already have an australia.gov.au account,  at My Account, click on 'Link to online services.'

You will then need to select the online service you would like to link to. 

Once you have proved you own the agency record, an agency online account will be automatically linked to your australia.gov.au account.