In January last year, a network-sharing agreement between Optus and TPG Telecom went live, giving Vodafone customers access to Optus' network towers, more than doubling its coverage area to one million square kilometres.
"It's fair to say for Vodafone, it's a business that has fundamentally changed in the past year," TPG chief marketing officer Bec Darley told investors at online an information day on Tuesday.
"The business has undertaken a multi-year transformation program on network coverage and experience, and the headline on that is Vodafone is back."
It now has the same network coverage as Optus and is just one per cent away from Telstra, after solving a structural issue that the standalone Vodafone brand had for many years, Ms Darley added.
"Network is now a hygiene factor," she said. "Vodafone is now a credible and confident alternative."
Meanwhile, TPG Telecom's market share in Melbourne has jumped one percentage point to 22 per cent since the network expansion, and is up by six-tenths of a percentage point to 23 per cent in Adelaide.
Nationally, TPG had a 16.8 per cent mobile market share in 2025, up from 16.0 per cent in 2022.
TPG also plans to double down on Felix, its five-year-old digital-only mobile brand for value-oriented consumers that's about 20 per cent cheaper for TPG to operate.
"We're not sending SIM cards out, we're not sending field merchandising teams out, we're not paying commissions," said James Gully, TPG's acting chief executive for consumer.
"It all happens 100 per cent digitally for Felix and for TPG."
TPG on Tuesday forecast that it would grow its digital-first subscriber base by 50,000 in the first half, while its traditional prepaid plans were expected to decline by 35,000.
Echoing complaints from other telecoms, TPG said the Australian Communications and Media Authority's spectrum renewal process was onerous for the industry and would raise prices for consumers.
TPG said the spectrum renewal would cost it around $21.1 billion over the five years from 2028 to 2032, but it could afford that given its strong operating cash flow and borrowing headroom.
In early afternoon trading, TPG shares were down 6.6 per cent to $3.74.
TPG Telecom was created in mid-2020 through a merger between Vodafone Hutchison Australia and TPG Corp.
Its other brands include internet service provider iiNet and prepaid mobile phone company Lebara.