Free Traffic Legal Advice

Aldi in Nottingham.  I was parked in an end of row bay with two wheels outside the bay into the traffic lane.

Therefore not parked entirely within bay.  However I have been issued with a parking charge with the wording 'Occupying More Than One Marked Bay' which form the photo evidence is clearly not the case.  I am 100 miles away so do not know the wording of the parking notice but suspect it says about parking within the bay so it is odd that they used this incorrect wording in the charge notice.  I will appeal on this basis but if they come back a second time with the correct wording will I then have no option but to pay or having used the wrong wording are they now no longer able to claim a different offence?   

Thanks for any advice.