Commonwealth Bank of Australia (CBA) told a public hearing that some of its financial planners had billed services to deceased clients.
In one case, an adviser collected fees from a former client for more than a decade.
Australia is holding a royal commission - its top form of public inquiry - into the nation's financial institutions.
Prime Minister Malcolm Turnbull ordered the inquiry last year following a series of scandals involving financial misconduct.
CBA told a hearing on Wednesday that it had regularly collected fees from customers for services that were not delivered.
On Thursday, bank
executive Marianne Perkovic said that practice extended to dead customers.
One adviser knew a client had died in 2004 but continued to collect monthly fees until 2015, the inquiry heard.
The commission was told that financial advisers involved in misconduct had been penalised with warnings by the bank.
CBA has previously faced scrutiny for alleged breaches of anti-money laundering laws, and for providing inappropriate financial advice.
Australia's Treasurer Scott Morrison has warned that financial executives could face strong penalties, including jail sentences, from evidence brought up at the inquiry.