The colonist is a person who pays his bills (7)
I believe the answer is:
settler
This clue is a triple definition!
'the colonist' is the first definition.
(synonyms)
'is' is a link.
'a person' is the second definition.
(settler is a kind of person)
'who pays his bills' is the third definition.
(I've seen this before)
(Other definitions for settler that I've seen before include "new inhabitant" , "One taking up residence in a new area" , "newcomer, perhaps" , "Colonist, pioneer" , "decisive blow" .)