CH82120 - Calculating the penalty: Amount of Penalty: Introduction


This guidance applies to returns and documents with a filing date on or after 1 April 2009 where the return covers a tax period beginning on or after 1 April 2008 seeCH81011for full details.

The amount of the penalty is based on the Potential Lost Revenue (PLR), see CH82160. You should work out the amount of the penalty by applying an appropriate percentage to the PLR depending on whether the inaccuracy was

  • careless, see CH81130
  • deliberate but not concealed, see CH81150, or
  • deliberate and concealed, see CH81160.

Where there has been an under-assessment and the person did not tell you about it, see CH81170.

Where the person has discovered an inaccuracy in a return and does not take reasonable steps to tell you about it, the inaccuracy will treated as careless even if was not careless at the time it was made, see CH81080.

The maximum penalty due is

Reason for penaltyType of inaccuracyMaximum penalty payable
Giving an inaccurate documentCareless30% of PLR
Giving an inaccurate documentDeliberate not concealed70% of PLR
Giving an inaccurate documentDeliberate and concealed100% of PLR
Inaccuracy discovered later but no reasonable steps taken to tell youTreated as careless30% of PLR
Understated assessment not notifiedN/A30% of PLR


You may reduce the penalty depending on the quality of the disclosure, see CH82400. The reduction may be restricted to a minimum amount, see CH82470.

A list of the relevant documents is at CH81060.