jointly vs collectively

jointly and collectively both are adverbs.

Word	Noun	Adjective	Verb	Adverb
jointly	No	No	No	Yes
collectively	No	No	No	Yes

As adverbs, jointly and collectively are synonyms defined as:

Other synonyms of jointly include conjointly, together with.

jointly (adverb)	collectively (adverb)
in conjunction with; combined	in conjunction with; combined
in collaboration or cooperation