Financial services firm Prudential has been fined £50,000 by the Information Commissioner's Office for mixing up two customers' accounts.

The customers share the same first name, surname and date of birth. Their records were mistakenly merged in March 2007 after an address mix-up by one of the customer's financial advisors. The issue was not successfully resolved until September 2010, the ICO said on Tuesday.

"Organisations must make sure the information they hold on their customers' files is accurate and kept up to date in order to comply with the Data Protection Act," ICO head of enforcement Stephen Eckersley said in a statement. "In this case two customer files were consistently confused and the company failed to remedy the situation despite being alerted to the problem on more than one occasion.

"This case would be considered farcical were it not for the serious sums of money involved."

Tens of thousands of pounds, meant for a retirement fund, were transferred to the wrong recipient's account. In addition, correspondence meant for each of the customers was sent to the other on a number of occasions.

This is the first fine made by the regulator that doesn't relate to data loss.