Single Status Update
As has been mentioned in several posts, there are different ways that parking infringements are dealt with:
Local Authorities - using the Civil Enforcement legislation.
Other authorities (airports, railway companies etc.) - using their own by-law legislation.
Private Parking Companies - which can only make civil claims for breaching
their contract. Only if they comply with schedule 4, Protection of Freedoms Act 2012 can they claim for unpaid parking charges from the keeper. That is the only legislation that is available to the them, but they very rarely do comply. That is one reason why they use words like 'contravention', PCN' and 'contravention number' in their paperwork, in an attempt to confuse the motorist and give the impression that their 'Parking Charge Notice' has the same legal standing and penalties as a 'Penalty Charge Notice' issued by a local authority.
There is civil regulation and criminal regulation, and the relevant procedure needs to be followed by the relevant authority. The problem is that neither apply to claims by the Private Parking Companies. They make up their own rules, and claim a breach of contract when they consider they have been broken.
If the claim is for unpaid parking charges, and they comply with Protection of Freedoms Act 1012 (which is very rare), they can claim that from the keeper. That act does not apply to land covered by legislation - airport, railway company etc. land. The companies can deal with the matter via their by-law legislation, ( not the R.T.A. legislation), but some don't and pass the matter to a Private Parking Company to deal with, but all they can rely on is a breach of contract by the driver. That is one reason why some of their paperwork has wording similar to civil enforcement paperwork, quote byelaws etc, to try to confuse the motorist that they are liable for the claim as the keeper - which they are not.