The Sunday Business Post newspaper (Ireland’s leading weekly paper dedicated to business news) carried a story this week about errors in calculating mortgage interest due to the 2008 Leap Year which have affected at least one Irish bank. This is an information quality problem we discussed previously on this blog.Of course, the bank’s are simply going to apply the interest missed out to the customer’s accounts retrospectively, with the average additional charge to customers being around €28.50, according to reports. However, the fact that this error has appeared in the national media, and the Halifax’s competitors are all stating that they have had no such problems, suggests that the cost to the bank may be greater in terms of negative PR. In this case the bank made a gross error in defining its information architecture and the core business rules for interest calculations (such as assuming 2008 was not a leap year), and it would seem their systems testing failed to catch the problem until after the event. However, as is often the case, the cost of non-quality information is being passed to the customer, making the immediate ‘problem’ go away (a shortfall in interest payments and profits) while masking the underlying root cause (failure to properly define and test information processing rules for core processes resulting in poor quality information).