They don't have the legal powers to issue fines and legal action has so many holes that you can argue against
An actual fine issued by a local authority is a completely different kettle of fish
It's not a fine, but it is a breach of contract. It establishes a debt, which is a civil matter, but it is enforceable.
It used to be the case in England & Wales (and still is the case in Scotland and Northern Ireland) that liability couldn't be automatically transferred to the registered keeper. So while they could get the RK details from DVLA, you could largely ignore them because they wouldn't be able to easily prove who was driving to breach the contract, so it wasn't worthwhile them chasing it. Since the Protection of Freedoms Act was introduced though, they are now able to transfer the liability to the registered keeper. It varies by parking company but many of them do follow through with this and it'll end up being a CCJ as
@Bletchleyite says, with the additional fees to boot.
In Scotland and NI you can, for now, fairly safely ignore them. The debt still exists but it's difficult to enforce unless someone admits who was driving. For repeat/persistent offenders, they do still sometimes go through the effort of trying to identify the driver though. Scotland is "in the process" of changing this to have RK liability like England & Wales but they've been "in the process" of doing this for years now.
Information request and response under the Freedom of Information (Scotland) Act 2002.
www.gov.scot
I can confirm that Section 8 of the Transport (Scotland) Act 2019 has not yet been commenced.
To provide some background on private parking, a number of changes to the parking industry were introduced by the UK Government in the Parking (Code of Practice) Act 2019. However, in June 2022 this Code of Practice was temporarily withdrawn following legal challenges from a number of parking firms. The UK Government is currently undertaking consultation to bring an amended Code of Practice into force, however we do not have a set timescale at present.
It is important that the amended Code of Practice is implemented to ensure that standards are set for the private parking industry around parking charges and debt recovery fees, before any secondary legislation to support Section 8 of the above mentioned Act is brought into force in Scotland.
Worth noting that airport property is often statutory land covered by byelaws in England & Wales, which stops it being "relevant land" for the purposes of the RK liability legislation, so you can also get away without paying airport parking charges, though again, the higher the total charges, the greater chance the parking company will make efforts to identify the driver(s).
Goes without saying that ignore the letters isn't qualified legal advice!