An increasingly complex tax system is  costing UK businesses an estimated £15.4 billion a year in compliance,  according to a report from the National Audit Office (NAO).
HMRC's cost of collecting tax has risen  by £563 million over the past five years due to added complexity in the system  plus investments in staff and IT.
During this period, the government's tax  yield rose by £113 billion in real terms, said the NAO.
HMRC estimates that compliant UK  businesses incur costs of £15.4 billion each year in meeting around 2,500  obligations across 27 policy areas. These include £6.6 billion of fees paid to  agents, accountants and other intermediaries, £4.5 billion of acquisition  costs, such as software, and £4.3 billion of internal costs.
The report warned that HMRC is  underestimating these costs as it does not take into account all taxpayer  obligations.
Frank Haskew, Head of Taxation, at the  Institute of Chartered Accountants in England and Wales (ICAEW), said:
'This  report highlights how the UK's increasingly complicated tax system is saddling  businesses and HMRC with extra burdens and costs, which are growing in real  terms. The report also substantiates our concern that the cost to businesses of  complying with their tax obligations is likely to be understated.'
Internet  link: NAO ICAEW