“15. It has long been part of the common law of this country that organs of the State must act fairly and in good conscience with its citizens. In our judgement there is nothing fair or reasonable in setting a computer system so that it does not generate a penalty notice until four months have gone by from the date of default, thereby ensuring that a penalty of not less than£500 will be due. We are in no doubt that the computer system could easily be set to generate a single£100 penalty notice immediately after the 19 May in each year. That is the course that a fair organ of the State, acting in good conscience towards the citizens of the State, would adopt. 16. As, in our judgement, HMRC has neither acted fairly nor in good conscience, in the manner described above, we do not consider that any penalty is recoverable over and above the£100 penalty for the first month unless HMRC proves (the onus being upon it) that even if such a penalty notice, which would have acted as a reminder, had been issued, the default would nonetheless have continued. It has proved no such thing.”