“Deemed delivered” 16/12 which is more than 14 days after 29/11, two working days allowed for posting.
There is no register of owners, you are the registered keeper.
You appeal, as the registered keeper, that you can not be liable for the actions of the driver, whom you will not be identifying. Sample appeals here, you may want to post what you plan to use here before sending.
The appeal will be rejected even though it’s correct, but it’s the start of the process in which you will end up paying nothing.
"Registered keeper" - got it

I've got this so far, please feel free to tell me what you think (below).
The process is an online form on their website.
From what it sounds like the process will be:
* I'll appeal the NTK on their website.
* They'll either reject it or I won't hear anything back at all.
* Presumably at some point I'll get a POPLA code from them (maybe I'll have to ask them again for it if not automatically provided?)
* I'll submit a similar appeal to POPLA.
* Hopefully NTK goes away at that point.
Dear Bank Park Management,
I am the registered keeper of the vehicle [Reg Number].
The alleged parking event occurred on 29 November 2025. Your Notice to Keeper is dated 13 December 2025, but I received it on 17 December 2025, which is outside the 14-day period required by paragraph 9(4) of Schedule 4 of the Protection of Freedoms Act 2012.
As the Notice was not delivered within the statutory timescale, you have failed to establish keeper liability. I will not be identifying the driver.
Please confirm that the charge has been cancelled or provide a POPLA code so that I may submit an appeal.
Thank you,
[My Name]
Registered Keeper