Federal politicians will put the bosses of Westpac and ANZ under the spotlight on Wednesday.
Since the bank chiefs met with the House of Representatives economics committee in March, the federal government imposed a bank levy in the May budget, an impost South Australia wants to mimic as an additional state tax.
The government is also preparing to introduce legislation for its banking executive accountability regime, which aims to deter the poor behaviour that has riddled the sector in recent years.
ATM fees have been independently dropped, led by an initiative of the Commonwealth Bank last month.
However, CBA, which along with National Australia Bank will be quizzed by the committee on October 20, enters this latest round of hearings under a dark cloud.
The bank is being prosecuted by money moving regulator Austrac over alleged money laundering and is being investigated by corporate regulator ASIC for possible breaches of disclosure obligations.
The Australian Prudential Regulation Authority also launched an inquiry into its governance, culture and accountability.
The economics committee first grilled the big banks in this format in October last year, in an attempt by the Turnbull government to fend off calls by Labor, the Greens and others for a royal commission into the sector.
This followed a series of scandals over several years that have robbed millions of dollars from mum and dad investors.
Those hearings drew a series of recommendations from the committee, most of which have been adopted.
These include a one-stop-shop for consumer complaints and increasing the powers and resources of the Australian Competition and Consumer Commission to investigate competition issues in setting interest rates by the banks.
"These hearings provide an important mechanism to hold the four major banks to account before parliament," committee chair, Liberal MP David Coleman said.