[3][4][5] On 9 September 2003, Chowdhury was appointed the chairman of the National Board of Revenue replacing Shoaib Ahmed.
[8] He was the first person to be appointed chairman of the National Board of Revenue on a contractual basis.
[9] He launched operations against black money after the amnesty period announced by the Bangladesh Nationalist Party government ended.
[16] The office was created after the Bangladesh Nationalist Party led government passed the Tax Ombudsman Act, 2005 after being proposed by M. Saifur Rahman, Minister of Finance.
[17] National Board of Revenue ordered its staff to cooperate with Chowdhury in 2008 to improve services which had been poorly received in 2007.