Mark Hall (pictured) is HMRC’s director of IT Services and also deputy CIO. Phil Pavitt, formerly CIO at Transport for London and Centrica, is the organisation’s Director General of Change and its CIO. While Hall does report directly to the straight-talking Pavitt, he says that the Director of Change half of the job fills most of Pavitt’s time. Hall is well respected by a number of commentators as having a straight focus and calm manner that is needed to guide the sheer high levels of change required at HMRC.Hall’s broad remit covers the IMS department, Live Services for applications and infrastructure, IT business alignment and development, architecture, project management teams, financial planning for IT, IT contracts management, IT solutions for requirements and build, internal transformation of IT and the management of the 1100 staff in IT, many of whom, he explains, are professional civil servants and not pure IT staff.As the government’s highest spending department and also its primary revenue source, HMRC has been set three stiff challenges in the latest government spending review.It has to maximise revenue flows so that people are paying the right amount of tax, reduce its cost base by 25 per cent and improve the customer experience. The biggest change is the 13 machine strategy which Hall described to CIO:“13 Machines is a consolidation and transformation project. These are the technologies for going forwards and they are as agile as possible, so we can implement policy changes as quickly as possible. We are trying to be far more agile with the architecture. They will serve us well for a very long time.”13 Machines will consolidate an estate of 550 applications to 13 core platforms. HMRC identified that the 13 platforms already existed within the department and that these would support the bulk of business process requirements.“We must re-engineer the IT to serve our requirements better so that we can segment and do business intelligence,” Hall says of the desire for a single customer view. The 13 machines will cover the core processes of HMRC: tax processing, pay as you earn (PAYE), National Insurance, VAT, benefits and tax credits. Underpinning the bulk of IT at HMRC is SAP, which manages everything from HMRC staff to case-flow and CRM.Previous CIO 100s have judged the UK’s IT leaders on the size of their IT estate, thus HMRC and its peers at the Ministry of Defence and the Department of Work & Pensions have always scored highly.  The CIO 100 judging panel felt that Hall and HMRC have a strong transformative vision, but the weight of savings and transformation required meant that the organisation has a lot to prove. The 13 Machine strategy and an analysis of the transformative vision from Hall and Pavitt meant HMRC got into the top 20, but all felt the size of its budgets and teams when compared to some of the top 10 organisations meant there was a lot to do at HMRC to pull it into that top tier. Read the CIO interview: CIO Profile: HMRC's Mark Hall on making tax collecting more responsive CIO Profile: HMRC's Mark Hall on job-sharing CIO Profile: HMRC's Mark Hall on IT rationalisation