Telco companies will be forced to comply with new rules if they suffer a major system outage.
Under industry standards brought in by the Australian Communications and Media Authority, telcos will have to put information on their websites to let customers know what has happened, should an outage take place.
Other communication methods, such as call centres or the media, would also need to be used to keep customers up to date.
Telco customers would also need be notified every six hours for the first 24 hours of an outage.
The rules, which come into effect from December 31, cover network outages which affect more than 100,000 services.
The changes are in response to the 2023 Optus outage, where millions of customers were unable to access the internet and receive mobile service, while thousands of people were unable to make emergency calls.
The telco has paid more than $12 million in penalties for breaching rules for triple-zero calls during the outage.
Communications authority chair Nerida O'Loughlin said telco customers would benefit from the disclosure rules if there was an outage.
"Recent examples have shown that telcos are not always as responsive with information during a major outage as they should be," she said.
"These new rules will ensure that telcos keep the lines of communication open, and that people impacted by a major outage aren't left in the dark about what's going on and when their service might be back."
Communications Minister Michelle Rowland said telcos had been willing to implement the reforms.
"We need to work together to ensure customers are provided with accurate, fulsome and timely information when experiencing significant disruptions to their critical telco services," she said.
"We will continue to work closely with the ACMA, industry and stakeholders to implement remaining recommendations to better prevent and manage any future network outages."
The communications watchdog is considering further rules on local outages by April.
"We are also looking at how best to extend rules to cover outages caused by natural disasters without interfering with time-critical communications from emergency service agencies," Ms O'Loughlin said.
"ACMA encourages telcos to prioritise keeping their customers updated when unplanned outages occur, regardless of how many people are affected by the outage."
