Turns up, the foreign credit application for the most part is in the post (6)
I believe the answer is:
parcel
'post' is the definition.
(thesaurus)
'turns up the foreign credit application for the most part' is the wordplay.
'turns up' says the letters should be written in reverse.
'the foreign' becomes 'le' (**).
'credit' becomes 'cr'.
'application' becomes 'app'.
'for the most part' means to remove the last letter.
'cr'+'app'='crapp'
'crapp' with its final letter removed is 'crap'.
'le'+'crap'='lecrap'
'lecrap' reversed gives 'PARCEL'.
'is in the' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for parcel that I've seen before include "'Bundle, package (6)'" , "Something wrapped up in package, as for posting" , "Wrapped item in post" , "Small piece of land" , "Piece (of land); something to post" .)