Fill up after pre-MOT work? Bill may include it (7,6)
I believe the answer is:
service charge
'work? bill may include it' is the definition.
I can't judge whether this definition defines the answer.
'fill up after pre-mot' is the wordplay.
'fill up' becomes 'charge' (charging is a kind of filling up).
'after' means one lot of letters go next to another.
'pre mot' becomes 'service' (I can't justify this - if you can you should believe this answer much more).
'charge' put after 'service' is 'SERVICE CHARGE'.
Can you help me to learn more?
(Other definitions for service charge that I've seen before include "A bistro may make one" , "Restaurant may have one" , "it may mean that extra 10%" , "Additional restaurant fee" , "Restaurant bill addition" .)