As thousands of people try to submit their tax returns, the main online portal for federal government services has gone down.
The MyGov site appears to be unavailable on Friday morning, returning an error.
The Department of Human Services said via MyGov's Twitter account there were "technical difficulties" with the website.
"We are urgently investigating the issue and we're working hard to fix this as quickly as possible," it repeatedly said in replies to people reporting the error.
Hi there, thanks for letting us know. There are currently some technical difficulties, including some people not being able to access myGov. We are urgently investigating the issue and we’re working hard to fix this as quickly as possible. We apologise for any inconvenience.— myGov (@myGovau) July 12, 2019
The Australian Taxation Office also tweeted that "some of our services (incl. the portals & our online services via myGov) are currently unavailable or experiencing slowness".
More than a million people have filed tax returns since the start of July - many more than usual - seeking to take advantage of recently legislated tax cuts.
The new single-touch payroll system means most workers have to access the online system to retrieve their payroll summaries for their tax returns this year.