Brat, not at home, collared by policeman informally for a fine perhaps (9)
I believe the answer is:
surcharge
'fine perhaps' is the definition.
The answer and definition can be both related to property as well as being singular nouns.
Maybe you can see an association between them that I can't see?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for surcharge that I've seen before include "Additional cost" , "Excess fee" , "additional amount" , "Additional payment" , "addition to bill" .)