ATO have advised:
29 December 2016
Systems outage 30 and 31 December
The planned outage to ATO online services (including the portals) originally scheduled for 26 and 27 December has been deferred and will now commence on Friday 30 December at 10.00pm EDT. We expect these services to resume during the day on Saturday 31 December and we will issue an alert when services are available.
The ATO website should be available during this period.
This outage will help ensure services impacted by the recent system issues are operating as well as possible at start of business on Tuesday 3 January.
Tax Practitioner, Lodgment Strategy and Engagement Support