List of charges arising out of spat about a king (6)
I believe the answer is:
tariff
'list of charges' is the definition.
(list of fees or charges to be paid)
'spat about a king' is the wordplay.
'spat' becomes 'tiff' (synonyms).
'about' means one lot of letters goes inside another.
'king' becomes 'R' (abbreviation for rex, king in Latin).
'a'+'r'='ar'
'tiff' enclosing 'ar' is 'TARIFF'.
'arising out of' is the link.
(Other definitions for tariff that I've seen before include "Duty; table of charges" , "Import duty, tax" , "Tax or duty to be paid on some imports or exports" , "Sentencing scale" , "Government tax on imports" .)