Wells Fargo agreed last September to pay $185 million to settle three government lawsuits over the bank’s creation of sham accounts. Thousands of employees, trying to meet aggressive sales goals, had created accounts in customers’ names without their knowledge. Workers who met the bank’s sales targets received bonuses — and those who did not risked losing their jobs.

At the time, Wells Fargo said that 2.1 million suspect accounts had been opened from 2011 to mid-2015. But it also acknowledged at the time that the problems may have begun earlier, and said it would expand its review to include accounts opened from 2009 to 2016.

Besides the additional accounts announced Thursday, the wider review uncovered a new issue: unauthorized enrollments of customers in the bank’s online bill payment service. Wells Fargo said that it had found 528,000 cases in which customers may have been signed up without their knowledge or consent, and will refund $910,000 to customers who incurred fees or charges. The service is now free, but once carried fees for some accounts.

“We are working hard to ensure this never happens again and to build a better bank for the future,” Timothy J. Sloan, Wells Fargo’s chief executive, said in a statement announcing the review’s results. “We apologize to everyone who was harmed.”

But one of the bank’s fiercest critics, Senator Elizabeth Warren, Democrat of Massachusetts, laid into it with a scathing statement: “Unbelievable. Wells Fargo’s massive fraud is even worse than we thought.”