Make sense to swap present company (6)
I believe the answer is:
cohere
'make sense' is the definition.
(I've seen this in another clue)
'swap present company' is the wordplay.
'swap' is a charade indicator (letters next to each other).
'present' becomes 'here' (both can mean in attendance).
'company' becomes 'co' (abbreviation).
'here' put after 'co' is 'COHERE'.
'to' acts as a link.
(Other definitions for cohere that I've seen before include "Be consistent" , "Hang together" , "Stick firmly together" , "Fuse together" , "Stick or hold together and resist separation" .)