In a POPLA appeal, you should put as many points as possible for the operator to rebut. You only have to win on a single point whereas that operator has to rebut, successfully, every point you raise.
POPLA will only consider whether the PCN was issued "correctly". No mitigation is taken into account. They will consider points of law and the BPA Code of Practice.
In ECP cases, they have often been won on signage alone. ECP signs are notoriously poor. For example, here is a recent assessors "rationale" for accepting an appeal against ECP:
Assessor supporting rational for decision
It is the parking operator’s responsibility to demonstrate to POPLA that it has issued a PCN correctly. In this case the appellant has stated there is insufficient notice of the sum of the parking charge itself.
Having reviewed the signs of the site in this case I must concur with the appellant on this point. The British Parking Association (BPA) has a Code of Practice which set the standards its parking operators need to comply with.
Section 19.4 of the code advises signs must give adequate notice to bring charges to the attention of motorists. In this case the sum of the charge is in a much smaller font to the conditions that precede it and I do not consider the parking operator has demonstrated compliance with this requirement.
Accordingly, I must allow this appeal. Whilst I note the appellant has raised other grounds in this case, as I have allowed the appeal for the reasons above, I will not be considering them.
As you can see, the appeal is upheld and all other points that were raised, are not considered.
So, You would start your appeal by listing all the points you want to raise. obviously, the failure of their ANPR/ticketing system is your main point. You should also include the breach of BPA CoP 19.4 whereby, if they are relying on PoFA to hold you, the keeper, liable rather than the driver, whose identity they do not know, that their signs do not adequately bring to the attention of the driver the charge for breaching their terms and conditions.
Normally, you would also include landowner authority to issue charges.
It would also assist in giving appropriate advice if we could see both sides of the NtK showing all dates with just your personal data, PCN number and the VRN redacted. There are often other PoFA failures that should be brought to the attention of POPLA which ECP will have to rebut.