There are ways to be exempt from council tax, and this is one of the most common in Burnley .......
"The property is unoccupied because a minister of religion will be moving in and it is from where he or she will carry out the duties of their office."
Guess how many 'Mosques' there are in Burnley..... over 1400
(I know the link is from Wigan council, but the same applies for the whole of England.)