Telstra Group (ASX:TLS) paid a AU$277,200 penalty for failing to conduct identity authentication in 15 unauthorized SIM swaps between January and October 2025 and not providing adequate protections to customers at risk of mobile number fraud, according to a statement from the Australian Communications and Media Authority (ACMA) released on Thursday.

ACMA's probe identified 13 instances where the company's agents failed to provide further fraud protections to customers who had either raised concerns or where Telstra had information to identify them as being at risk of fraud involving their service, the statement said.

Customers collectively experienced financial losses of at least AU$39,500 due to fraud, according to ACMA Member Samantha Yorke.

ACMA also accepted court-enforceable undertakings from the company to boost fraud prevention processes and improve staff training, per the statement.