UKPC are stubborn, and are likely to push this 'all the way', up to launching a court claim (although if they do this, they have a recurring habit of discontinuing before it reaches the courtroom). You (or whoever UKPC have written to, your partner?) would also seem to have a number of avenues of defence open to them. So, whilst we can't offer any guarantees, if you're prepared for a bit of a faff, there's a decent chance you won't have to pay anything.
Firstly, that signage appears to be forbidding. That is, it doesn't make an offer for anyone to park on certain terms, it simply prohibits any and all stopping/parking. Given that there is no offer of consideration made by UKPC, there cannot be any contract formed between the driver and UKPC. If there is no contract, then no money is owed.
Secondly, even if the signage
was capable of forming a contract (which will be denied), the driver must be given the opportunity to read the terms and conditions on offer and decide if they accept or reject them - a driver would struggle to read the entirety of that sign in the space of 33 seconds. Section 13 of the British Parking Association's
Code of Practice specifies as follows:
13.1 The driver must have the chance to consider the Terms and Conditions before entering into the ‘parking contract’ with you. If, having had that opportunity, the driver decides not to park but chooses to leave the car park, you must provide them with a reasonable consideration period to leave, before the driver can be bound by your parking contract. The amount of time in these instances will vary dependant on site size and type but it must be a minimum of 5 minutes.
13.2 The reference to a consideration period in 13.1 shall not apply where a parking event takes place.
UKPC may seek to argue that 13.2 applies here depending on what actually happened during the time the car was stopped (did a passenger alight?), but even then, I think it's a credible point that 33 seconds is insufficient for it to be deemed that a 'parking event' took place.
Thirdly, even if the signage
was otherwise capable of forming a contract (which, as above, will be denied), the content of it is poor - the £100 charge is hardly displayed prominently, instead being displayed in a small font amongst other text.
Fourthly, there is the point you have already made about the error with the address. If they are deemed not to have 'specified' the relevant land, then they are unable to recover the charge from the registered keeper, instead only being able to pursue the driver (who they do not know), as they will be deemed not to have complied with the requirements of Schedule 4 of the Protection of Freedoms Act (2012) - there's a link to it in my signature.
