The Middlesbrough Evening Gazette reports as below:

You may be able to get compensation for your incorrect speeding fine!

The start of every speed limit must be marked with a pair of signs. The pair of signs at the start of the limit are known as "terminal signs". If there is not a valid pair of terminal signs the limit may not be enforced. See the table below for examples of the sign types that are causing these problems.
 
 

Sign	Valid sign?	Valid terminal sign?	Why?
	yes	yes	Two prescribed signs mounted on a yellow backing board is OK.
	no	no	The lower symbol is not a prescribed sign and invalidates the backing board.
	no	no	The black border makes this one sign. Since the sign is not prescribed it is invalid.
	no	no	The lower symbol is not a prescribed sign and invalidates the backing board. The black border makes this one sign. Since the sign is not prescribed it is invalid.
	yes	yes	Two prescribed signs mounted on a grey backing board is OK.
	no	no	The lower symbol is not a prescribed sign and invalidates the backing board.
	yes	yes	This sign is prescribed.
	yes	yes	This sign is prescribed.
	yes	no	This sign is prescribed as an advanced warning. It cannot be modified to create a terminal sign.
	yes	no	This sign is prescribed as a camera warning and speed limit reminder.