General assessment procedures: De minimis levels
Normally the only time you would not raise an assessment when you discover an error is where the value falls below the de minimis level.
If you discover individual errors of £100 or less, and the total of these individual errors does not exceed £100 under-declared per accounting period and £100 overall, you should not raise an assessment.
If any of these errors is the result of a persistent misdeclaration or it is felt that the issue needs to be exceptionally reinforced you may assess irrespective of the de minimis limit.
Officers should be aware that the mainframe computer will automatically accept minor errors it discovers on a return. For example, if the figures entered in box 3 and 4 do not equal box 5 and the difference is less than £100, the error will be ignored and the return will be processed.
If the error is more than £100 the return will be rejected and returned to trader for correction. Assessments should be based on the difference between the correct liability and the declared liability.