The chief executive of Wells Fargo has apologised to customers for the US bank illegally opening accounts to boost sales targets, in a hearing at the Senate Banking Committee on Tuesday.
The bank was fined $185m (£142m) and accused of “widespread illegal practice” by the regulator.
“I am deeply sorry that we failed to fulfil our responsibility to our customers, employees and the American public,” said John Stumpf.
“We did not get it right.”
The fine imposed on the bank by the US Consumer Financial Protection Bureau was the largest ever imposed by the regulator.
Its investigation found that bank workers had “illegally” signed up customers for more than two million deposit and credit card accounts.
Employees also issued debit cards without customers’ knowledge, even creating fake email addresses to unknowingly sign up consumers to online banking services, the regulator said.
Wells Fargo said it set up an independent review of its sales practices dating back to 2011 and had taken “disciplinary actions, including terminations of managers and team members who acted counter to our values”.
Mr Stumpf has ignored calls for him to step down from his post in the wake of the scandal.