work permit vs working papers

work permit and working papers both are nouns.

Word	Noun	Adjective	Verb	Adverb
work permit	Yes	No	No	No
working papers	Yes	No	No	No

As nouns, work permit and working papers are synonyms defined as:

work permit and working papers: a legal document giving information required for employment of certain people in certain countries

Other synonyms of work permit include work papers.

work permit (noun)	working papers (noun)
a legal document giving information required for employment of certain people in certain countries	a legal document giving information required for employment of certain people in certain countries
	records kept of activities involved in carrying out a project