Andrew Haldenby was Director of the cross-party think tank Reform from 2005 to 2019 during which time Reform became the leading Westminster think tank for public service reform and productivity. Speakers at its events included Cabinet and Shadow Cabinet Ministers of all parties including Rt Hon Sir Keir Starmer.

Reform contributed prominently to the debate on public spending and public service reform and published research papers on civil service reform including issues of management and decentralisation.

He stepped down from Reform in 2019 to advise a number of companies working with government and public sector in the UK. He joined the Effective Government Forum in 2024.