CH407930 - Charging penalties: recording and calculating penalties on the National Penalties Processing System (NPPS): manual penalty cases: non-registered contractors
Where you find that a contractor has not registered for CIS, they are liable to Sch55 failure to file penalties, see CH62300, for the return or returns that they should have submitted.
These are charged using NPPS.
In cases where you have established liability to a 12 month failure to file and withholding information penalty, you should include this in the same penalty notice.
Note: For periods where the contractor is registered, do not enter the details into NPPS for any non-behavioural penalties, or the penalty will be charged twice (CISR will raise them too).