The Indian firm, which is one of three ride-sharing companies in Australia, will close its app on Friday, according to the email, after more than six years of operation.
The Transport Workers Union said it would seek an urgent meeting with the company after the shock closure, which followed similar announcements for grocery and food delivery services.
Ola, which operated in Sydney, Melbourne, Brisbane, the Gold Coast, Adelaide, Canberra and Perth, had employed more than 50 staff across Australia and New Zealand and boasted of more than 1.5 million users.
In an email to customers, the company said it would "discontinue operations" in Australia on April 12.
"You must not take any rides with any vehicle purporting to be an Ola vehicle or Ola driver from 12th April 2024," it said.
"Ola has not authorised any driver or any other party to use the Ola brand or provide rides on Ola's behalf."
It's understood the company's New Zealand operations will also close, and Ola's app is rejecting new sign-ups from Australian users.
Attempts to contact the company's local representatives were unsuccessful, with emails bouncing and phone lines redirecting callers to the company's website.
Transport Workers Union national secretary Michael Kaine criticised the company's sudden exit from Australia, saying it showed why gig workers urgently needed a minimum standard of protections.
"Workers in the gig transport economy have for too long been ripped off minimum wage and other rights and put under deadly pressure to prioritise speed over safety when delivering food," he said.
"We will seek an urgent meeting with Ola to seek the best possible outcome for affected ride-share drivers."
Mr Kaine said the announcement followed a difficult period for transport workers, after the closure of Milkrun, Send and Voly, and the industry was eagerly waiting new standards from the Closing Loopholes Bill that were expected to take effect in August.
Ola is one of three ride-sharing companies in Australia, alongside China-based Didi and US tech giant Uber.
The company, which is headquartered in Bangalore, launched in Australia in 2018.
In 2020, the company told NSW regulators it had more than 1.5 million users across Australia and New Zealand, and employed more than 50 local staff.
Ola failed to pose a significant threat to market leader Uber in Australia, however, with a 2020 Roy Morgan report finding 93 per cent of Australians rode with Uber during a three-month period, but only 20 per cent used Ola and 14 per cent used DiDi.
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