Tickets issued by private companies
Private companies can issue tickets to drivers parked on their property, but the rules are not the same as local authorities.
If you receive a ticket in a private car park, such as a supermarket car park, or private multi-story car park, remember that it is not criminal law, but contract law that applies. The driver enters into a contract with the landowner when they driver into the car park.
This means that it is only the driver that can be subject to a ticket from a private company. If they do not know who the driver was, they cannot claim a penalty. They have no legal right to demand that you identify the driver.
If you are approached by a member of staff inside a private car park there is no obligation for you to assist them in any way
If the company wish to pursue a claim in the small claims court, they have to prove that you were the driver of the car. Any comments that you make may assist them in this aim, so best to say nothing.
If you refuse to pay, the private company has to pursue you through the small claims court. It is up to them to prove a breach of contract so look at the terms carefully. These are usually printed on a sign at the entrance to the car park.
Additionally, you may be able to reduce any fine issued by a private company. Under contract law, they can only claim for any loss they have suffered because of your offence. They may try to claim a penalty of, say, £100, but in law they may only be entitled to any revenue they had lost. So, if you pay £2 to park for one hour, but stay for three hours, they can only claim for two hours of lost revenue, which is £4.
Read more:
http://www.thisismoney.co.uk/fight-parking-tickets#ixzz0xiPUMdCx