I have, this week, received another parking charge for £80 from Parking Eye at the RUH.
Our mobility vehicle was registered with RUH reception last year as having a disabled driver. 
Last November, after registering, I received a parking charge from said company, which admittedly was later withdrawn as a token of “goodwill”.
Earlier this year, both my son and son-in-law received charge notices of £80. Fortunately they had both retained their receipts so that ParkingEye had to withdraw their claim.
It would appear that there is a problem with their equipment or maybe something that requires more investigation.
My advice to anyone using the RUH car parks – keep your receipts.
Ken Day
Chantry Court