CH404600 - Charging penalties: interaction between penalties: details and examples: penalties for misuse of rebated oil apply under both FA08/Sch41 and FA1994/S9
The FA08/Sch41 penalty should be assessed for the period up to the day before the detection. This is because two penalties of £250 were charged on that day for the acts of taking in and using red diesel.
You therefore need to deduct from the Potential Lost Revenue (PLR) the duty on the fuel in the vehicle on that day.
Example
A Road Fuel Testing Unit (RFTU) road side check results in Frank receiving two FA94/S9 penalties of £250.
Your post-detection audit identifies that Frank has misused red diesel for 12 months before the day of the RFTU check. The amount of duty payable is £20,000.
You estimate that the duty on the petrol in the tank was a maximum of £50 based on a full tank.
Therefore the PLR for the FA08/Sch41 penalty is £19,950.