So there was a glitch in the system, which is being rectified admittedly with a little bit of annoyance but with some phone calls, postage etc its resolved. To take it to the extent of letting the parking company make the inquiry at the DVLA▸ starts a whole chain of events of letters, county court, even as far as bailiffs. Yes it is a civil offense but these car parking companies see non payment in the same light as shoplifting and will pursue it to the end.
I wouldn't call it a civil offence. The word 'offence' implies some from of criminality. It is far from similar to shoplifting. Breaking rules in a car-park (excluding council run ones) is at worst a breach of contract. For which the onus is on the party at loss to prove their case. First off, they have to prove you were the driver. If you were the driver then ask them for proof, don't volunteer the information yourself. No need to incriminate yourself!
Damages for breach of contract should reflect the actual loss, so an arbitrary penalty of say ^50, which often rises exponentially with each subsequent demand for payment, for what is actually a minimal loss is unfair. This is covered by the Unfair Terms in Consumer Contracts Regulations 1999:
Schedule 2 Indicative and Non-Exhaustive List of Terms which may be Regarded as Unfair
<snip>
(e) (a term) requiring any consumer who fails to fulfil his obligation to pay a dis-proportionately high sum in compensation.
There is plenty of case-law out there where private parking companies have attempted to sue for breach of contract for amounts grossly in excess of the actual loss, but I've yet to see a single case where they have been successful.
If you've broken a rule in a private car park, then pay a sum relevant to the actual loss suffered by the parking company/landowner. Overstayed by an hour? Pay one hours parking fee. Occupied two bays? Pay twice the fee for your stay. Even then, only pay up if the parking company can prove their loss. DO NOT pay the extortionate amounts on the invoice stuck on your window, or demanded in subsequent letters.
Remember though,
IANAL▸ EDIT: Legal proceedings CAN be initiated under Railway Byelaw 14 by an agent acting on behalf of a Railway Operator, but the car parking companies at railway stations rarely go down this route, because the fines issued by a magistrates court do not go to them. They prefer the invoice approach coupled with threats of county court action, because, if you are mug enough to pay up, they get money.