A difficult year for HMRC has seen a rise in departures by individuals holding senior management positions, research from UHY Hacker Young has revealed.

The taxman saw 42 of its senior civil servants - all on salaries of at least £47,000 - leave the department in 2011/12, compared to 29 in the previous financial year.

In a separate study by UHY Hacker Young, the firm found that a quarter of its clients were also issued the wrong tax code this year, leading to the incorrect payment of tax to HMRC.

Roy Maugham, tax partner at UHY Hacker Young, said: 'Failings in HMRC's performance over the last year have attracted a lot of attention, and the jump in resignations is indicative of the rocky patch that HMRC is experiencing.

'Stability at the top benefits business, personal taxpayers and HMRC. Without stable management and continuity, we could see service levels at HMRC slip,' Maughan warned.

In response, an HMRC spokesperson said: 'Overall, resignations at HMRC have fallen over the last four years, and in a department of around 68,000 staff, it is inevitable that some will decide to leave or retire.

'HMRC is committed to providing stability and good service to our customers. We have already increased the accuracy of tax codes to 98%, and announced the recruitment of an extra 1,000 people to answer the phones, and increased tax yield year-on-year.'