General term for a room or building where clerical or administrative work is done; can refer to a company office, a lawyer's office, a government office, etc.
彼は毎朝9時に事務所に着く。
He arrives at the office every morning at 9.
事務所の電話番号を教えてください。
Please tell me the office phone number.
The lawyer has set up his office in front of the station.
She works at a small design office.
We plan to relocate the office to a new building next month.
I visited the office regarding the contract.
事務所 is a general office for administrative work, while 事業所 emphasizes the operational or production site of a business.
事務所 refers to a private company's or professional's office, while 役所 specifically means a government or municipal administrative office.
law office; law firm
welfare office; social security office