Issues arising from an otherwise normal system update at the Australian Taxation Office (ATO) took its website offline for almost four hours yesterday.
An ATO spokesman said the website became unavailable shortly after 11am. It was restored with limited functionality at 2.45pm.
The spokesman pinned the outage on "data corruption during a normal system update process".
He later clarified that the update was a "standard content update" that happened at four scheduled times daily.
As of 4.30pm, further work was underway to restore full functionality to the site's drop-down menus.
Web information company Alexa found the ATO website to be the 88th most visited site in Australia. 5,928 visitors were expected to have been affected by the outage, based on visits the ATO received the previous week.