Simon MacDowall has resigned and will be leaving HMRC in October to become a director at Emic Communications, which specialises in internal comms.
MacDowall departs after 12 years at Whitehall, during which time he has worked for six secretaries of state and seven permanent secretaries.
MacDowall said he was making the move because it 'feels like the time'. He said: 'You reach a point when you say "I think that's long enough and its time to take these skills to the private sector".'
He became comms director at the former Department of Social Security in 1999 and later moved to the Ministry of Defence before taking the HMRC job in 2007.
MacDowall added that the main issues his successor would need to handle included 'supporting the HMRC Change programme with excellent internal comms, along with effective external comms with customers and stakeholders as HMRC makes improvements to services'.
He leaves after completing an internal review of HMRC's comms, which was aimed at integrating devolved comms functions and focusing them on helping to achieve HMRC's strategic objectives.
The HMRC comms director role oversees more than 200 people in central government and comms workers around the country. The responsibilities include press, marketing, internal comms, corporate comms, digital comms and customer information.
MacDowall is staying until October to help with handover to his successor, a search for whom is due to start shortly.