John Whiting, the CIOT tax policy director, is to take up a senior role at HMRC as a non-executive director.
The former PwC tax partner, who now heads up the Office of Tax Simplification, will take up his new role as chair of HMRC's audit and risk committee on 1 April.
He told Accountancy: 'I have long argued for there to be more non-executive directors with tax experience at HMRC. I want to maintain the links I have with tax professionals and CIOT and people in the small business community and I want to use that knowledge and those links to be objective and constructive and help HMRC.
Whiting will step down from his role at the CIOT - but will remain involved with the organisation.
'HMRC is going through a huge and challenging period of change and I hope I can help with that. It is in everyone's interests that they are successful,' he added.
His tax policy role with the CIOT meant he had regular contact with the UK tax authorities and politicians. He is also a member of the First-tier Tax Tribunal.
Whiting was awarded the OBE in 2008 for services to the tax profession and was the first recipient of the 'Tax Personality of the Year' accolade.
He joins former RWE Npower group chief executive, Volker Beckers, and ex-Morrisons group HR and communications director, Norman Pickavance, who were both appointed to the main board on 1 January 2013.
The trio will take on the roles left vacant following the departures of John Spence, Phil Hodkinson and Ian Barlow - who became HMRC's new lead non-executive - in September 2012.
Beckers will chair a new "scrutiny committee", while Pickavance will join the "people, nominations and governance committee".
David Gauke, Treasury Secretary, said: 'These appointments provide a rich mix of board-level experience. They have a lot to offer the HMRC board and will bring new and further capability and credible challenge to board discussions and to the new executive team.'
HMRC also announced the appointment of Edwina Dunn, Janet Williams, Leslie Ferrar and Paul Smith to further strengthen HMRC board committees.
Dunn will take up an adviser role to the main board, Williams will be appointed to the scrutiny and people, nominations and governance committees, and Leslie Ferrar and Paul Smith will take up roles on the audit and risk committee.
HMRC chief executive Lin Homer, said: 'I am delighted with these appointments. They all have vast experience to share with HMRC which will help us as we face the challenges of the future.'