Its poll of 100 HR directors shows two thirds (67%) of HR departments are having to deal with tax inquiries from staff, outstripping concerns about pension fund performance, which are cited by 60%.

Restrictions to lifetime pension contribution allowances which were cut to £1m in April this year from £1.25m, and annual contribution allowances – currently set at £40,000 but reducing to £10,000 for employees earing between £150,000 and £210,000 - are also generating substantial numbers of inquiries. Around 45% of HR departments say they have had to deal with concerns from higher-earning staff worried about breaching allowances.

HMRC figures show the number of taxpayers who are exceeding the annual allowance is rising – 1,539 people paid a tax charge in the 2015/16 tax year for breaching the £1.25m allowance generating a total of £126m compared to 1,482 the previous year generating £78m.

Steve Watson, Portus Consulting commercial director, said: ‘Tax issues are highly complex and employees may not know what their annual allowance or lifetime allowance is until the end of the tax year.

‘HR departments face a wide range of issues and keeping on top of pension taxation rules is yet another challenge which can lead to problems if called upon to provide detailed advice.’