Hi DF. Thank you for this advice. It is much appreciated. I will certainly follow up on this and will report the result on this forum

Thanks BazzaS. I should have mentioned in my original post that it was actually my wife who was using the car at the time, but they have written to me as the registered keeper. I can prove that I was actually at work 40 miles away at the time. Is it actually necessary to invite them to pursue the driver (without telling them who), or will they just eventually go away if I continue to ignore them?

About ten years ago, while living in England, I received a PCN after parking at a retail park and exceeded the time limit. Following the advice I read on CAG, I completely ignored this along with several follow-up letters and they eventually stopped coming. I now live in Scotland and have recently received another PCN from Tesco's for exceeding the time limit in their car park. I ignored it and have subsequently received two follow-up letters from Highview Parking. The latest one says I have seven days to pay before they employ the services of a debt-collection agency. Should I continue to ignore, or have the goalposts moved since my previous episode ten years ago. Also, can anyone advise if the rules of engagement are different in Scotland?