The signage is not capable of forming a contract with a driver who does not hold and display a valid permit, because it makes no contractual offer of parking to such a driver.
The sign is framed in prohibitive terms: “CUSTOMERS ONLY” and “PRIVATE LAND, PERMIT HOLDERS ONLY”, with an instruction that a “valid permit must be obtained from shop and displayed”. Those words do not offer parking on terms to the general public. They define a closed class of authorised users and exclude everyone else. A person who is excluded cannot accept an offer that is not made to them. In those circumstances there is no “agreement” capable of being formed by conduct, and no contractual charge can arise.
Although the sign also contains a clause stating that if a vehicle “remains” or “fails to comply” the motorist agrees to pay £100, that wording does not convert a prohibition into a contractual licence. Properly construed, the sign is “no unauthorised parking”. The legal consequence of an unauthorised vehicle being left on private land is, at most, trespass. Any remedy for trespass lies with a landowner (or a party with a proprietary interest), and it is not a contractual “parking charge” owed to a parking contractor.
Further, the allegation itself (“not clearly displaying a permit”) presupposes that the driver was entitled to park on the basis of a permit but failed to display it properly. That is a fundamentally different case from “unauthorised parking”. If the operator’s case is that the driver had no valid permit on display, then by the operator’s own signage the driver fell outside the class of authorised users (“permit holders only”), meaning no contract could have been formed in the first place. The allegation therefore supports the defence: it points away from any contractual relationship and towards a bare allegation of unauthorised presence, which cannot give rise to a contractual sum.
Accordingly, even leaving aside the absence of Keeper liability, the claim fails on formation. The sign is forbidding to non-permit holders, no contract was available to be accepted by them, and the asserted “parking charge” is not a recoverable contractual debt.
