In message , tim.....
writes
It entirely depends on the terms of the contract.

No it doesn't, it depends upon the law, and UK law specifically bans
the collection of Punitive damages in any type of contact - only the
government may punish you. Any contract clause that attempts to do
so will always be void.

But I can enforce a published parking charge on private land?

That's not damages for breach of contract, it's a charge for the actual
goods/service that you are selling. (And can legally be whatever
amount that you want it to be - that the customer will pay).

So, provided I have a clearly visible/worded notice explaining the
charge applicable to unwanted parking on gateway access aprons, I am at
liberty to detain, without damage, any such vehicle?


--
Tim Lamb