central government office; head office
Refers to the main office of a government ministry or agency, as opposed to local branches. Also used for the headquarters of certain organizations.
本庁から通達が来た。
A directive came from the head office.
He works at the police headquarters.
Used within an organization to refer to the speaker's own main office, often in contrast to branch offices. Common in internal communications.
本庁では新しいシステムを導入します。
This office will introduce a new system.