Ignore the "mugs discount". If you don't want to pay a penny to UKPC then follow the advice I give you here. I can guarantee that with greater than 99.9% certainty.
There is no legal obligation on the
known keeper (the recipient of the Notice to Keeper (NtK)) to reveal the identity of the
unknown driver and no inference or assumptions can be made.
The NtK is not compliant with all the requirements of PoFA which means that if the
unknown driver is not identified, they cannot transfer liability for the charge from the
unknown driver to the
known keeper.
Use the following as your appeal. No need to embellish or remove anything from it:
I am the keeper of the vehicle and I dispute your 'parking charge'. I deny any liability or contractual agreement and I will be making a complaint about your predatory conduct to your client landowner.
As your Notice to Keeper (NtK) does not fully comply with ALL the requirements of PoFA 2012, you are unable to hold the keeper of the vehicle liable for the charge. Partial or even substantial compliance is not sufficient. There will be no admission as to who was driving and no inference or assumptions can be drawn. UKPC has relied on contract law allegations of breach against the driver only.
The registered keeper cannot be presumed or inferred to have been the driver, nor pursued under some twisted interpretation of the law of agency. Your NtK can only hold the driver liable. UKPC have no hope at POPLA, so you are urged to save us both a complete waste of time and cancel the PCN.