Indigo PN rejection but no popla code

"Failure to display" is indeed a Byelaw offence if the signage says that you must display a valid permit or have paid for a mobile parking session. Byelaw 14.2(ii) states that you have to abide by what the signs say.

Only the driver could be legally liable for a Byelaw breach. The owner and the keeper could not be found guilty by a Magistrate's Court of a breach of Byelaws caused when someone else was driving. Byelaws 14.1, 14.2 and 14.3 refer to the "person in charge", which means the driver only.

Indigo has now introduced wheel clamping, ANPR and persuaded the BPA to allow them to suspend the POPLA appeal process. All this has happened very quickly over the last few weeks. This is outrageous.

Let's assume you get a windscreen ticket at a station car park managed by Indigo. You appeal to Indigo, they reject your appeal of course. You now have nowhere else to turn. Unless you pay the penalty, Indigo may well apply a wheel clamp at some point in future because they have a record of your non payment and station car parks tend to be used multiple times per week by each driver. They will not bother going to a Magistrate's Court, because they will get no financial benefit. Why do that, when they can screw £200+ out of you by using a wheel clamp?

Let's say you ignore the windscreen ticket. Indigo will get the keeper details from the DVLA and send out a Notice to Keeper letter. By the time this arrives, Indigo will say that it's too late to appeal to them. But they would reject this appeal anyway. As above, if no-one pays up then it's likely the car will be clamped when it is again in the car park.

How to fight this? You could buy an angle grinder and keep it in your boot. Or you could pay the clamp release fees and then sue them in the small claims court, using the following arguments:
(1) Indigo Park Solutions UK Ltd has no written authorisation from Govia Thameslink Railway to manage any of GTR's station car parks. All their tickets and clamps are therefore fraudulent.
(2) The Byelaws state that clamping can only be used when a Byelaw has been breached, not when there is only an alleged breach. Only a Magistrate's Court can prove that a Byelaw breach has actually taken place.
(3) Clamping on private land was made illegal by the Protection of Freedoms Act 2012, unless the clamper has "lawful authority". So does Byelaw 14.4.(ii) provide this authority? No it does not. The Byelaws rely on section 219 of the Transport At 2000 as their enabling legislation. Nowhere in this Act does it mention power to create Byelaws relating to clamping. The fact that 14.4(ii) exists is due to it having been written in 2005, when clamping was allowed by virtue of the then existing common law. POFA2012 changed all that and there has been no further enabling legislation since then which would make clamping in station car parks lawful.
(4) Railway Byelaws make no mention of the car park operator being able to charge a clamp release fee.
(5) Since Indigo Park Solutions UK Ltd have no written authority to manage any of the GTR station car parks, they can have no "reasonable cause" to request your personal data from the DVLA. Doing that would be a breach of the Data Protection Act. Recent examples of damages for DPA breaches, awarded in the small claims track, run to about £750 per incident.

Happy parking.