Ignore it.

A private company cannot fine you. Only the Police or Councils can do that.

What you have received is a speculative invoice inviting you to pay, in the same way you get emails from Nigerian princes who want to put millions into your bank account.

You have already paid for parking and should simply ignore them from now on. You might get a series of letters making ever increasing demands, but that's all they can do, write to you. They'll never go to court as they know they haven't got a leg to stand on.

For more information have a look at the discussion forums at www.pepipoo.com, or www.moneysavingexpert.com.

When you mention a PCN do you mean a PArking Charge Notice and not a Penalty Charge Notice?

Penalty Charges are issued by Councils etc and ahve considerable legal force.

Parking Charge Notices from landowners or private parking companies are based on contract law and have get outs.

If issued befroe 01/102012 then ignore. They can only enforce against the driver and he/she may be difficult to identify. POst 01/10/12 they can pursue the registered keeper - a target that might be easier to hit . In that case you might havre to rely on evidence of having apid even if RM details were not input.