EM3267 - Discovery: varying an assessment

Sometimes after an assessment has been made, new information may become available that shows the amount assessed is either excessive or too little.

Once an assessment has been made, it can only be varied upon appeal. There are only four situations when it can be amended

1) An agreement with the taxpayer to settle the appeal, under s54 TMA 1970
2) HMRC notifies the taxpayer of an offer for a review and sends their view of the matter, but the taxpayer does not respond within the acceptance period. The view of the matter letter is treated as an agreement under s54(1) TMA 1970 by virtue of s49C(4) TMA 1970
3) A review officer can conclude that the amounts in an assessment should be varied, under s49E(5) TMA 1970. This is treated as an agreement under s54 TMA 1970 by virtue of s49F(2) TMA 1970 unless the taxpayer rejects the conclusion and appeals to the tribunal
4) The tribunal vary the assessment under s50(6)/(7) TMA 1970

If the assessment was not under appeal, it will have become final and determined so a further assessment will need to be considered.

TMA1970/S49
TMA1970/S49C
TMA1970/S50

Enquiry Manual