The Consumer Financial Protection Bureau will not penalize Citigroup for overcharging credit card customers provided the bank returns $335 million to the 1.75 million borrower accounts that are due refunds.

Credit card customers who keep up with their payments are often entitled to a lower interest rate, and Citibank said in February that a computer error led to some accounts missing out on a lower rate.

The CFPB decided that the bank deserves credit for finding the problem itself and flagging it to the agency, so it did not fine Citi.

The CFPB fined Citibank and its subsidiaries $35 million in 2015 and forced the bank to refund $700 million after finding that the bank pushed customers into unwanted credit card services.

The decision could encourage banks to be more careless with consumer accounts if they do not fear a penalty when things go wrong, a consumer advocate said.

“What message does this send other banks?” said Karl Frisch, executive director of Allied Progress.

Citigroup said in a statement that it was happy to resolve the matter with regulators and “we reiterate our sincere apologies to our customers for not correcting these issues sooner.”

Citi said it first discovered the software issue in 2016. The bank disclosed the credit card problems in February and promised to refund $335 million at that time.