NEW YORK (AP) — The Consumer Financial Protection Bureau has fined Regions Bank $7.5 million for illegally charging customers for overdraft protection.

Regions Bank, which has branches across 16 states, mostly in the South, has already refunded $49 million in overdraft fees to its customers, the CFPB said Tuesday. The agency said the Birmingham, Alabama-based bank will have to hire a consultant to determine if more customers are due refunds.

Since July, 2010 the Federal Reserve has required banks to have customers opt in before charging them for overdraft protection services. The CFPB said Regions Bank did not change its systems until July 2012, and didn't fully comply with the rules until August 2013.

The CFPB said the fine could have been much higher if the bank hadn't self-reported the violation to regulators.