trade name; firm name
Refers to the official registered name under which a company conducts business, similar to a corporate name.
会社の商号を変更するには登記が必要です。
To change a company's trade name, registration is required.
商号 is the legally registered trade name used in commercial law contexts, while 社名 is the everyday business term for a company's name.
Compound of 商 (commerce, trade) and 号 (name, designation). The term is used in legal and business contexts to denote a company's official name.