Distribute cards to do business (4)
I believe the answer is:
deal
I believe this clue is a double definition.
'distribute cards' is the first definition.
(I've seen this before)
'do business' is the second definition.
(as in dealing with another business)
'to' acts as a link.
(Other definitions for deal that I've seen before include "Plank of softwood timber" , "Distribute (cards); wood" , "Fir or pine wood" , "understanding" , "Sawn wood" .)