contingent on vs contingent upon

contingent on and contingent upon both are adjectives.

Word	Noun	Adjective	Verb	Adverb
contingent on	No	Yes	No	No
contingent upon	No	Yes	No	No

As adjectives, contingent on and contingent upon are synonyms defined as:

contingent on and contingent upon: being determined by conditions or circumstances that follow

Other synonyms of contingent on include contingent, dependant on, dependant upon, dependent on, dependent upon, depending on.

contingent on (adjective)	contingent upon (adjective)
being determined by conditions or circumstances that follow	being determined by conditions or circumstances that follow