The government agrees with the Committee’s recommendation. Recommendation implemented 5.2 The department has been addressing its legacy technical debt since 2019 and received funding of £268 million at the 2020 Spending Review to continue the work to improve the agility, resilience and security of its IT estate. The estate comprises over 6,000 servers and over 550 associated IT systems so is an extremely complex and inter-dependent one. The plan to tackle legacy technical debt has focused on a number of areas: • Rationalise/Streamline: Rationalising the department’s IT estate – to date 20% of the department’s total services have been de-commissioned or retired; • Remediate: Addressing high priority technical debt to replace out of support and old components, so that the core system security is enhanced, together with strengthening perimeter controls protecting the department’s IT systems. The department has spent £36.3 million on this activity in Financial Year 20-21; • Migrate: The next step in this programme of work is to migrate these systems to the Cloud. Hosting savings will be delivered, thus reducing baseline IT spend. These systems can then be further transformed as part of full service transformation (multiple IT systems grouped together form a service such as Personal Tax or VAT), which is agreed industry-standard practice; and • Transform: Focusing on defining and consolidating system delivery centred around strategic components, reducing operating cost and concentrating management activities around a reduced set of components which support HMRC operations. This both reduces the operating cost and the security attack surface area, which helps HMRC defend its systems. 5.3 The ODP details the plans on how the department is remediating technical debt and the work HMRC have done to develop core foundational structure elements for HMRC.