Significant cyber breaches like the one levelled against Optus have the power to send shock waves through Australia's financial institutions, the central banks warns.
The Reserve Bank of Australia says the threat of further cyber incidents remains high and has the potential to destabilise the financial system by increased fraud.
Financial fraud from stolen data could then undermine confidence in banks and the banking system, the RBA says in a report.
The recent Optus breach and other large-scale hacks of personal data highlight the need for regulators and financial institutions to continue strengthening their cyber resilience, it says.
In response to the Optus breach, the government is moving to reduce red tape on the sharing of information with banks to allow them to implement better safeguards and monitoring systems.
The changes, announced on Thursday, would let the telcos temporarily share key information such as driver's licence, Medicare and passport numbers with financial service firms.
Optus would also be able to share identifiers with Commonwealth, state and territory agencies to prevent fraud.
The changes are due to be presented to the governor-general on Friday.
Communications Minister Michelle Rowland says the institutions should be ready to move as soon as they come into effect after wide consultations with them.
"This is designed in order to provide those financial services institutions with the information they need to keep consumers safe," she told ABC radio on Thursday.