Company on the top of token (6)
I believe the answer is:
coupon
'token' is the definition.
(I've seen this before)
'company on the top' is the wordplay.
'company' becomes 'co' (abbreviation).
'on' is a charade indicator (letters next to each other).
'the top' becomes 'upon' (I am not sure about this - if you are sure you should believe this answer much more).
'co'+'upon'='COUPON'
'of' is the link.
Can you help me to learn more?
(Other definitions for coupon that I've seen before include "means to buy goods" , "betting slip" , "Voucher or ticket" , "Entry form" , "Token" .)