service agency vs service bureau

service agency and service bureau both are nouns.

Word	Noun	Adjective	Verb	Adverb
service agency	Yes	No	No	No
service bureau	Yes	No	No	No

As nouns, service agency and service bureau are synonyms defined as:

service agency and service bureau: a business that makes its facilities available to others for a fee; achieves economy of scale

Other synonyms of service agency include service firm.

service agency (noun)	service bureau (noun)
a business that makes its facilities available to others for a fee; achieves economy of scale	a business that makes its facilities available to others for a fee; achieves economy of scale