Experts say the Microsoft outage is likely to cost businesses billions.
RSM Australia Risk Advisory partner, Ashwin Pal, says small business will be hit the hardest.
The financial impact is expected to last weeks.
The Microsoft outage is calculated to cost Australian businesses billions of dollars, with experts warning small businesses will be the hardest hit by the technology failure.
A widespread outage, which started about 3:15 am AEDT, has hit platforms including Outlook, with many users having trouble accessing emails and encountering errors across the Microsoft suite of products.
Workers across multiple types of businesses have reported being unable to access email or SharePoint, with some resorting to using fax machines to keep operating.
RSM Australia Risk Advisory partner Ashwin Pal said the cost to professional service businesses, such as lawyers or accountants, would be hundreds of thousands of dollars per hour.
"It's not just the initial downtime, it's more actually about then the catch up effort because that costs money," he said.
"Because now when things do normalise, you're going to have to spend money to actually catch up because of all the backlog."
He said the impact of the outage was amplified by the 3.9 million businesses globally that used the Microsoft suite, with many not having backup systems, resulting in huge costs to the economy.
