"They've told everyone just to leave their food and leave the store". Many have left full trolleys behind.
A national technical outage brought sales to a standstill at the busy Mackay city store this afternoon.
Shopper Sharni was among those asked to leave her groceries behind at the Hampton Park store in Melbourne. At Haymarket in Sydney, customers were told to return in "an hour", according to one tweet for ABC journalist Michael Janda.
In a statement, Woolworths said the outage was related to an IT systems update before registers came back online by about 4.30pm.
"The registers are now coming back online in our stores".More news: Jenna Bush Hager Tearfully Opens Up About Barbara Bush's Health
More news: Bank of America's cost-cutting drive pushes profit to record
More news: City must confront painful reality of life after Guardiola
Chief executive of the company Brad Banducci "apologised unreservedly to customers and store teams for the inconvenience caused".
The grocer is yet to confirm the cause of the outage.
Woolworths stores across the country have had to shut down registers and are unable to make sales.
Shoppers have taken to Facebook across Australia to complain about the outage, accusing the supermarket chain of "ruining dinner plans".
SBS News has contacted Woolworths for comment.