Figure a troop leader has to be paid (3)
I believe the answer is:
vat
'has to be paid' is the definition.
I can't judge whether this defines the answer.
'figure a troop leader' is the wordplay.
'figure' becomes 'v' (I am not sure about this - if you are sure you should believe this answer much more).
'leader' indicates taking the first letters.
The first letter of 'troop' is 't'.
'v'+'a'+'t'='VAT'
Can you help me to learn more?
(Other definitions for vat that I've seen before include "Barrel - tax" , "Fermentation vessel" , "Large tank for liquids, or kind of tax" , "Large tub; tax" , "A tax on a large container?" .)