home office vs main office

home office and main office both are nouns.

Word	Noun	Adjective	Verb	Adverb
home office	Yes	No	No	No
main office	Yes	No	No	No

As nouns, home office and main office are synonyms defined as:

home office and main office: (usually plural) the office that serves as the administrative center of an enterprise

Other synonyms of home office include central office, headquarters, home base.

home office (noun)	main office (noun)
(usually plural) the office that serves as the administrative center of an enterprise	(usually plural) the office that serves as the administrative center of an enterprise