The Commonwealth Bank is urging the government to consider allowing people to share personal data held by public agencies, saying it could "significantly" cut loan approval times if it had access to Tax Office data.

Amid recent debate about the sharing of consumer data, the country's biggest bank has argued that greater access to public and private data could help to reduce fraud, regulatory costs and credit risks.

Banks will be forced to allow customers to share their data with a rival from the middle of this year, under a regime known as open banking. But the banking giant says there could also be a case for getting government authorities to share data, too.

"To the extent government can make more of the data it holds available to citizens for legitimate purposes, either through giving individuals the opportunity to share their own data more readily with private sector entities, or by making large anonymised data sets publicly available, this should be encouraged," CBA said in a submission to the Senate's fintech inquiry.