Major telcos remain divided on an inquiry into whether customers should be able to use a different mobile network if they are left without service.
The consumer watchdog on Wednesday announced it will launch a probe to tackle the monopoly of mobile service providers after recognising the burden faced by many in regional and rural Australia.
The Australian Competition and Consumer Commission said the inquiry would likely last one year and decide whether telecommunication companies have to share their phone towers.
"There are growing calls for the ACCC to intervene to regulate wholesale mobile services, particularly in regional areas," watchdog commissioner Anna Brakey said.
"Consumers expect and need affordable, reliable and high-quality services. Businesses and investors need confidence to make efficient investments".
Unlike Europe and North America, Australia does not have domestic roaming - the ability for a mobile phone to automatically connect to another network when your own provider's service has a weak or no signal.
For example, if someone is with Optus and unable to make a call due to poor service, their phone would automatically connect with a different network provider, like Telstra or Vodafone, that can provide reception.
The watchdog said it would only declare mobile providers share their infrastructure if it will benefit Australians.
A Telstra spokesperson said the telco opposed mandates for domestic mobile roaming.
"It results in worse long-term network outcomes for all Australians, especially those in regional Australia," the spokesperson said.
"It does so by weakening investment incentives and reducing customer experience and reliability through increased congestion and the risk of signalling storms."
Optus said it was onboard with the announcement of the inquiry. "We welcome the ACCC's inquiry and the opportunity to contribute to this important discussion about the future of mobile connectivity in Australia," an Optus spokesperson said.
The announcement comes after recent scandals that involved the two largest telecommunication companies, Telstra and Optus.
Telstra's nationwide mobile outage in July left users unable to make calls or access data on their mobile phones, while some EFTPOS transactions were also impacted.
It caused a 32-hour shutdown of Victoria's V/Line regional train network when the outage knocked out critical train radio systems and left thousands of regional and rural passengers stranded.
Legal action was also launched against Optus in late July after an outage in September 2025 left its customers unable to dial triple zero for 14 hours.
This network failure has been linked to two deaths.
The consumer watchdog's latest announcement has also been welcomed by Communications Minister Anika Wells, who said the inquiry was timely.
In September, the federal government introduced legislation into parliament requiring mobile carriers to provide access to voice and SMS coverage for Australians nationwide, by 2027.
