CH403110 | Charging penalties: calculating penalties: the information you need to calculate a penalty: inaccuracies
From HM Revenue & Customs · Compliance Handbook
Before you can calculate a penalty you will have:
in cases involving offshore matters, established the territory category, see CH403140
established the type of behaviour, see CH402000
established the type of disclosure, see CH403202
determined any reductions for quality of disclosure, see CH403203
determined any special reduction, see CH403250
in Income Tax or CIS enquiries, checked the filing date to see if any tax geared failure to file penalties need to be deducted from the inaccuracy penalty, see CH404450
You will need these details for each tax period and each tax regime.