Flitty - you have not received a FINE. It is an unenforceable INVOICE. Read Martin Lewis' advice from moneysavingexpert.
http://www.moneysavin...ivate-parking-tickets
Private parking tickets are unregulated, unlike Council or Police Penalty Notice Charges.
You have not committed a crime.
Also see here
WATCHDOG MAY 2010
https://www.youtube.com/watch?v=XAIcdi9niHA
Under no circumstances contact the Parking ticket company. This is civil law and not criminal law. They must send letters to the Driver not the registered keeper. And they cannot prove who wa driving.
Read all the threads on moneysavingexpert.
Do not worry.