7,000 KBC Bank Ireland customers were accidentally told they were receiving a higher interest rate on their savings than the rate they were actually being paid.
The back of the KBC Bank customers' statements said they were being paid 1% more than the correct rate.
The issue came to light following a review by the bank in April.
It found while it had applied the correct interest rates to accounts, an incorrect rate was printed on the reverse of their statements.
The bank said "the error was rectified immediately and new statements were issued to customers" and "no customer was adversely impacted or lost out financially in any way".
KBC Bank Ireland said it informed the Central Bank about the issue.
It is understood that because the issue was rectified within 40 days, the Central Bank will not be taking action against KBC on the issue.
"As required under regulatory compliance procedures, the Central Bank of Ireland was notified of the situation and the matter is now closed," KBC Bank stated.
In a statement the Central Bank confirmed it was informed by KBC "of an error in April 2016 in relation to an incorrect interest rate summary table being included in statements for some KBC Regular Saver customers".
It added: "Where errors are identified, the Consumer Protection Code 2012 requires errors to be resolved speedily.
"The Central Bank engaged with KBC in relation to this matter and notes that KBC has issued corrected statements to all impacted customers."
