Strong customer identity checks will be required under new rules from the telecommunications regulator to stop scams targeting customer interactions with providers.
The rules respond to a rise in 'SIM-swap scams', where fraudsters use an individual's personal details to get a new SIM card and take control of their phone number.
The Australian Communications and Media Authority say those scams have cost individual victims around $28,000 on average.
ACMA's scam task force chairwoman Fiona Cameron said the racket could cause significant loss.
"SIM-swap scams can cause a lot of harm as scammers take control of your phone number and then use that to gain access to your online banking accounts," she said.
"SIM-swap fraud is particularly egregious as it leads to identity theft and significant financial losses."
The new rules, which kick in from June 30, require telcos to carry out stronger identity checks on higher-risk transactions like requesting new SIMs, changing accounts and disclosing personal information.
ACMA's enforcement options for any breaches of the rules include court action.
"These new rules require multi-factor authentication of your identity such as confirming personal information and responding with a one-time code consistent with how other essential services like banking operate," Ms Cameron said.
"We expect these rules will go a long way to stamping out unauthorised transactions like SIM-swap fraud and improve safeguards for telco customers."
