The CBA boss spoke at a public hearing at Parliament House in front of the House of Representatives economics committee, where he expressed concern over how banking customers were being hit in their savings.
“I think we’re over-relying on income [taxes]. I don’t think we’re taxing wealth as heavily as we could,” Comyn said in Canberra.
“I think it’s part of a broader structural issue that needs to be addressed. I understand that the changes are always very unpopular.
“I think the tax system at the moment is not as efficient, simple and fair as it could be.”
Comyn acknowledged he was no tax expert and said his remarks were not a criticism of any government.
He said it was a crucial reform that would help Australians during the cost-of-living crisis.
It follows a new report from Anglicare, Widening the Gap, which found the richest Australians have 90 times more wealth than the poorest in the country.
This wealth gap was blamed on negative gearing and capital gains tax concessions.
Comyn hit back at suggestions superprofits from corporations were contributing to this issue.
Earlier during the parliamentary inquiry on Australia’s big four banks, Comyn labelled the Greens’ proposed tax on big companies “insidious populism”.
The Greens announced on Wednesday a “Robin Hood reform” proposal which would tax excessive profits of big corporations at 40 per cent.
“The policy that was announced yesterday is just [one reflecting] insidious popularity… and I think it will drive a fundamental distrust over the next decade,” he said.
“I just see too often now, particularly in external environments, claims that are made that just are not demonstrably true, and that is weakening and driving a fundamental distrust across citizens.
“You must be seeing it, we are seeing it – and it is a real cause for concern and I just don’t think the right thing is to position things when they’re factually incorrect.”