Tiscali Quicklinks. Please visit our Accessibility Page for a list of the Access Keys you can use to find your way around the site, skip directly to the main navigation, to the page content, or to more links within money.
The disclosure comes a day after the revenue demanded the right to take cash from people's bank accounts without a court order if they failed to pay their tax bills on time. Richard Bacon, Tory MP for South Norfolk, said: "Given that over a million tax records contain errors, it is far from certain that HM Revenue and Customs should be allowed to interfere with the bank accounts of potentially innocent taxpayers."
The report says some £157m has been overpaid by 540,000 taxpayers - averaging £290 a time - with pensioners being particularly vulnerable to mistakes.
Some £125m has been underpaid by taxpayers - averaging £250 a time - with many facing surprise extra bills when Revenue and Customs staff realised their mistake.
The revenue blamed the errors on the increased complexity of processing income tax owing to people changing jobs more often, as well as the need to process certain cases manually.
The report revealed that the introduction of a car assembly line approach to checking tax returns resulted in big increases in errors in the first six months of the operation.
Some £9.7m was spent on introducing the system, pioneered by Toyota and Unipart,.....continued below
The report says that once the system is bedded down it will save staff and make the process more efficient.
Guardian Unlimited © Guardian Newspapers Limited 2007