Xavier Einaudi did not want to wait for Wells Fargo to send him a check.

The bank informed Mr. Einaudi that it was closing all 13 of the checking accounts it provided his roofing company, CRV Construction, for a reason it called “confidential.” The letter said the accounts would be closed on June 27, and he would be mailed a check for the balance in his accounts.

Mr. Einaudi went to his branch and collected the money, so he did not have to wait for a check to arrive in the mail. But the accounts did not close on the preset date.

For weeks after the date the bank said the accounts would be closed, it kept some of them active. Payments to his insurer, to Google for online advertising and to a provider of project management software were paid out of the empty accounts in July. Each time, the bank charged Mr. Einaudi a $35 overdraft fee.

Mr. Einaudi called the bank’s customer service line. He went to his local branch. Nobody could help him. “They told me, ‘The accounts are closed out — we cannot do anything,’” he said.

By the middle of July, he owed the bank nearly $1,500.

“I don’t even know what happened,” he said.

Current and former bank employees said Mr. Einaudi got charged because of the way Wells Fargo’s computer system handles closed accounts: An account the customer believes to be closed can stay open if it has a balance, even one below zero. And each time a transaction is processed for an overdrawn account, Wells Fargo tacks on a fee.

This is intentional, not an accident by IT.

Wells Fargo is rotten from top to bottom, and regulators should burn it to the ground.