The Department’s complacency about the level of underpayments inherent in its approach to administering State Pension has led it to fail pensioners. The Department’s highly manual systems and complex State Pension rules has led to calculation errors and the underpayment of thousands of pensioners. The Department, however, argued that low annual error rates on State Pension led it to focus assurance attention elsewhere, despite the detrimental impact on those underpaid. In addition, its quality assurance arrangements were inadequate and missed opportunities to detect, correct or prevent these errors. The Department hopes that, over time, it will become better at identifying small-scale errors that may mask more systemic issues. However, errors continue to be made even when re-assessing pensions awards as part of the correction exercise, leaving thousands of pensioners still not receiving what they are due. And examples such as the absence of regular reporting on State Pension enquiries make us concerned that senior management is not focused on designing a data strategy that detects errors in a more systematic way. 6 Underpayments of the State Pension Recommendation: The Department should start treating underpayments on State Pension as seriously as overpayments and set out to the Committee in its Treasury Minute response to this report what it is going to do both to prevent future errors and to strengthen its detection of systemic issues that lead to errors.