Zero in change for one’s close friends (5,4)
I believe the answer is:
alter egos
'close friends' is the definition.
(I've seen this in another clue)
'zero in change for one's' is the wordplay.
'zero' becomes 'O' (O resembles 0).
'in' is an insertion indicator.
'change' becomes 'alter' (synonyms).
'for one's' becomes 'eg's' (both can mean 'for example').
'alter'+'egs'='alteregs'
'o' going into 'alteregs' is 'ALTER EGOS'.
(Other definitions for alter egos that I've seen before include "Soul mates" , "confidants" .)