Telstra’s national mobile network outage last week was one of the worst incidents of its kind in living memory. More than 600 calls to Triple Zero were not connected, putting lives at risk. Public transport services in New South Wales and Victoria collapsed, causing commuter chaos. And businesses, especially small to medium ones, may have lost millions in revenue. Making matters worse, Telstra had been warned about the need to ensure that “single point of failure” problems did not cause cascading core network outages. Now, the Australian Consumer Communications Action Network (ACCAN) is calling for the federal government to introduce mandatory domestic mobile roaming. But what exactly is domestic mobile roaming? And could it help prevent some of the problems caused by a major outage like the one Telstra experienced last week? Switching servicesDomestic mobile roaming is the ability for your mobile phone to automatically connect to mobile infrastructure that provides the strongest connection – no matter which company you pay your bills to.This means your mobile phone could connect to mobile infrastructure owned and operated by Telstra, Optus or TPG Telcom (Vodafone) wherever you are across Australia.This policy has widespread public support. ACCAN’s Consumer Sentiment Tracker shows 73% of 1,014 respondents supported the introduction of domestic roaming. Only 5% were opposed. According to ACCAN, domestic mobile roaming would help expand the availability and reliability of existing access to mobile coverage to more consumers – especially in remote and regional areas. It would also reduce the price of mobile services by improving competition and network access for consumers.ACCAN also says it would simplify “camp-on” procedures during major outages, in which a phone automatically jumps onto another available network to ensure people can still call Triple Zero. As the recent Telstra outage – as well as last year’s Optus outage – shows, these procedures don’t always work. Improving life for consumersHowever, not everyone agrees. For example, in 2017, the Australian Competition and Consumer Commission (ACCC) decided against mandating domestic roaming. It found this approach would not promote competition “to a significant extent” and could make it harder for new telcos to enter the market.The ACCC also found that mandated domestic mobile roaming could lead to mobile network operators raising prices in regional areas “to reflect the additional costs of providing services in these areas”. But the experience of other countries that have already mandated domestic mobile roaming shows otherwise. For example, the New Zealand government mandated domestic roaming as a “specified service” in 2001. It renewed the mandate in 2023 because it had delivered successful competition and improved access outcomes for consumers. The Canadian government also mandated domestic roaming in 2015. It is still in place now. The key benefits have been improved competition and coverage across a vast landmass similar to Australia. Importantly, it hasn’t disincentivised mobile carriers from spending on new infrastructure. A January 2026 survey of the Australian economy by the Organisation for Economic Co-operation and Development (OECD) also criticised the lack of competition in Australia’s telco market. It said:Barriers to entry are particularly high in regional areas, where coverage is often limited to a single provider’s network infrastructure. This lack of competitive pressure has contributed to relatively high retail prices and limited service quality improvements relative to OECD peers.To address this, the report encouraged infrastructure-sharing obligations.A sensible stepDomestic roaming could reduce the disruption – including to Triple Zero services – caused by an outage on one mobile network. Depending on the implementation strategy, it would enable people’s phones to seamlessly connect to a competitor’s network. It would also help ensure there is greater visibility and greater scrutiny of telecommunications infrastructure, as it would be shared between competitors. This could potentially reduce the risk of companies using obsolete or outdated equipment. In turn, this would strengthen the resilience of the broader network and reduce the risk of a major outage. Mobile domestic roaming could also prompt mobile network providers to focus on other sources of competitive advantage, beyond network coverage. This could include improving their overall performance and offering additional perks such as partnerships with streaming companies. Consumers would be the main beneficiaries of this. Australia is a large nation that already subsidises the deployment of mobile infrastructure in regional and remote areas. Any mobile carrier that argues it is entitled to subsidies if domestic mobile roaming is mandated should be reminded of the more than $1 billion in subsidies that have been provided to the carriers over the past couple of decades through the Mobile Black Spot Program and other programs run by the federal and state governments.All of this shows that the Australian government should act now to mandate domestic roaming.Mark A Gregory has previously received funding from Australian Research Council, .au Domain Administration and the Australian Communications Consumer Action Network.