As Dave notes, it's seldom advised to ignore private parking charges in England and Wales.
With this being Smart Parking, you have a very easy way to get out of this. They choose not to make use of Schedule 4 of the Protection of Freedoms Act 2012 to be able to recover charges from the registered keeper*. As such, you have no liability. You could therefore appeal along the lines of the below
as the keeper (no telling them who was driving!):
Dear Sirs,
I have received your Parking Charge Notice (Ref: ________) for vehicle registration mark ____ ___, in which you allege that the driver has incurred a parking charge. I note from your correspondence that you are not seeking to hold me liable as the registered keeper, under Schedule 4 of the Protection of Freedoms Act 2012 ("The Act"). You have chosen not to issue a Notice to Keeper in accordance with The Act, and it is now too late for you to do so.
There is no obligation for me to name the driver and I will not be doing so. I am therefore unable to help you further with this matter, and look forward to your confirmation that the charge has been cancelled. If you choose to decline this appeal, you must issue a POPLA code.
Yours,
If appealing online, be careful there are no drop down/tick boxes that cause you to identify who was driving, and keep a close eye on your spam folder for their response. If they do not respond within 35 days, chase them.
* If you are not the registered keeper, tell us before submitting anything, as the approach will need to be different.
