Vodafone Australia lost more than 1.2 million customers in 2013, and admits it faces more work improving the perception of the company.
The telco says most of its customer losses occurred in the first half of the year, and customer numbers grew slightly in the final three months, to 5.3 million.
The removal of many inactive accounts was a contributor to the fall in the company's customer base.
Vodafone Australia is half way through a three year turnaround strategy, and has been working to improve its network's coverage, speed and reliability.
A fifty per cent owner of the telco, Hutchison Telecommunications, said on Monday Vodafone Australia needed to transform its "brand sentiment".
"Changes to consumer perception are lagging behind network improvements," it said in its financial accounts for 2013.
Hutchison Telecommunications said its share of Vodafone Australia's loss in 2013 was $246 million, an improvement on a loss of $409 million in 2012.
Revenue dropped by 13 per cent in 2013, and the impact of customer losses on revenue is not expected to be reversed until 2015, Hutchison Telecommunications added.
But it said Vodafone Australia is no track in its turnaround strategy.
