Up to 300 jobs are at risk across Australia after Vodafone announced it would shut down its Crazy John's mobile phone operation.

Vodafone will end the Crazy John's brand on February 20, News Ltd reports, more than 20 years after it was created by Melbourne entrepreneur John Ilhan.

Vodafone said it would try to redeploy some of Crazy John's 300 staff to other parts of its business.

Crazy John's customers would be incorporated into the larger Vodafone store and dealership network, News Ltd said.

Vodafone bought the brand from Mr Ilhan's widow Patricia for an estimated $150 million but has been struggling to keep customers due to poor network coverage.