The way I understood it is if its a true PCN (Penalty Charge Notice), rather than a ‘PCN’ (Parking Charge Notice), then they’re legally enforceable, and unless you really do have a genuine appeal, just pay it – this is normally what you would get ticketed on a council owned car park, on the street, etc. However a ‘Parking Charge Notice’ issued by the likes of Parking eye, etc, is not legally enforceable as you have not entered into a contract with the land owner to pay to park on their land. Parking on private land is trespass and as such is a still (curently LOL) a civil matter. The land owner, or the parking operator have no legal right to issue a fine. They make them look like a real PCN for obvious reasons of putting the frighteners on people. Its been a few years since I’ve done this, but if it’s issued by a parking management company, not the council, then I would ignore them – their only route to legally get money from you is to go to small claims court and sue for damages to property – which they won’t win because you didn’t damage anything. Plus they can’t be bothered to go down that route. They’ll say they’re passing it to collections, but they can’t send baliffs, they can’t do anything apart from keep sending more letters to you. eventually they give up.
Be very careful about this advice! I believe there was a case that set precedent that they can and will pursue you. Best to at least appeal then decide if it’s worth chasing.
Beavis vs Parking Eye is the case
https://www.lawgazette.co.uk/law/supreme-court-dismisses-85-parking-ticket-challenge/5051987.article#:~:text=Beavis%20v%20ParkingEye%20hinged%20on,any%20loss%20from%20an%20overstay.