The Inland Revenue and Customs and Excise merged last year with the aim, according to executive chairman Sir David Varney, of ensuring "small businesses will know where they stand, with simple information on what they have already paid and what they need to pay."

But eight out of ten small and medium-sized enterprises (SMEs) questioned by the think tank Tenon Forum said they had not noticed any difference in their relationship with the taxman.

Tenon spokesman Andrew Hubbard told The Times that HMRC still had time to prove itself.

He said:

"It would have been nice if the HMRC had found some opportunities to show taxpayers that its creation had been a good thing, but it has only been a year.

"If people have not noticed a difference in three years' time, that will be a problem."