By Marcus Leach
HM Revenue and Customs (HMRC) have said that around six million people are set to receive tax rebates averaging £400, while another million will learn they have underpaid their tax by about £600.
Letters will be sent out by HMRC over the coming months, with those in the position of owing money able to pay it off in instalments.
The new computer system used by HMRC picked up on the errors for a second year running, although HMRC went on to say that the number of cases with error would drop "as the new system beds in".
Those who will be told they have underpaid tax are expected to owe between £500 and £600 on average.
"Money that is owed going back many years is now going to be automatically paid back as we get the tax system up to scratch," said an HMRC spokesman.
"We are getting cases that were left unreconciled up to date as quickly as possible. Anyone owed money will be paid back with interest without the need to contact us.
"The fact is there will always be some cases at the end of every tax year that require an under or overpayment to balance but these cases will reduce as the new system beds in."
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