Verification of company land occupied by business (12)
I believe the answer is:
confirmation
'verification' is the definition.
('confirmation' can be a synonym of 'verification')
'company land occupied by business' is the wordplay.
'company land' becomes 'conation' (I can't explain this - if you can you should believe this answer much more).
'occupied by' means one lot of letters goes inside another.
'business' becomes 'firm' (firm is a kind of business).
'conation' going around 'firm' is 'CONFIRMATION'.
'of' is the link.
Can you help me to learn more?
(Other definitions for confirmation that I've seen before include "Endorsement" , "Proof; a religious ceremony" , "Christian rite - additional proof" , "religious rite" .)