The taxman has offered an olive branch to some late self-assessment filers after the system failed to cope with the last minute rush to meet the 31 January filing deadline.

In its statement online HM Revenue & Customs said: 'We explained that where users experienced problems with the SA service on 31 January 2008 or 1 February 2008, and were unable to file by midnight 1 February 2008, we would accept claims for "reasonable excuse" in the usual way.'

For those who failed to file by 31 January due to the disruption HMRC said it would 'remove any late filing penalty and treat the return as filed on time where the problems with the HMRC service were the cause of the delay and the return was filed within a reasonable period afterwards'.

'Penalty notices for any returns not filed on time are issued automatically and are due to be dispatched on 22 February 2008. However, we have now stopped the issue of penalty notices, and the extension of the enquiry window for online returns filed using the HMRC software on 2 and 3 February 2008.'

Individuals submitting paper returns received in local offices by close of business on 4 February 2008 (in letterboxes in the morning or arriving by post or by hand during the day – following the Special Commissioners’ decision in Steeden v Carver) were also given a reprieve.

The taxman added that where a return is filed 'within a reasonable period', and the delay was due to the problems, 'we will also accept appeals on the ground of "reasonable excuse" and remove the penalty for online returns filed on 4 February 2008, or later, and paper returns filed on 5 February 2008, or later'.