The Treasury acknowledges the Committee’s comments on the historic challenges in understanding the reasons for the cost increases. However, as noted in the response to Recommendation 25, the Treasury approved NS&I’s Full Business Case for the Programme in December 2023, subject to conditions, which included the requirement for NS&I to develop a Cost Management Plan and a Benefits Realisation Plan, both of which were completed and approved by the Treasury in March 2024. These plans clearly define the scope and costs for the full Programme and how benefits will be tracked and realised. NS&I provides a breakdown of actual spend for the Programme on a monthly basis, which is reviewed by the Treasury and has been in line with the approved expenditure. The Treasury also holds quarterly assurance meetings with NS&I at which spend data is reviewed and validated. The Treasury continues to scrutinise the Programme and ensure that NS&I has robust processes in place to track and manage its costs. NS&I has significantly improved the quality of its financial data for the Programme since the NAO report. NS&I have robust financial controls in place and have recently completed an external review of its financial management, controls and processes which found that its practices are strong and comply with financial accounting standards. It found that NS&I’s cost management plan contains clear and comprehensive financial information on all aspects of the Programme. It also includes comprehensive monitoring of costs and associated governance which aligns to best practice and good governance. NS&I is continually looking for ways to improve the quality of financial information. NS&I are also developing a new approach to reporting of its cost data to make it more comprehensive and accessible for the next Programme business case. This will be an improved single source of data which will include a full breakdown of the Programme costs with clear cost categorisation.