Germany's biggest lender Deutsche Bank transferred 28 billion euros (34 billion dollars) by mistake in a transaction made before Easter, the bank confirmed on Friday.
The bank sent the money to another Deutsche Bank account at the Eurex derivatives exchange and not a client on March 16, a spokesman in Frankfurt said.
A much smaller, unspecified amount was meant to be sent instead of the erroneously high figure, which is higher than the bank's 24-billion-euro (30-billion-dollar) market value.
No damage came as a result of the error, with the transaction being cancelled a few minutes after it was made.
The bank says it has reviewed the reasons for the error and taken steps to prevent it from happening again.
The mistake occurred in the final days of the now retired chief executive John Cryan.
