What I'm paid once I'm working (6)
I believe the answer is:
income
'what i'm paid' is the definition.
(earnings for a job)
'once i'm working' is the wordplay.
'working' is an anagram indicator.
'once'+'im'='onceim'
'onceim' anagrammed gives 'INCOME'.
(Other definitions for income that I've seen before include "Financial gain accruing over a given period of time" , "Money gained over time" , "Money received as wages, interest etc" , "Salary" , "Money from investments or for work" .)