The commercial code defines it as one who conducts distribution or purchases for others, under one's name, as a business, (Article 551 of the commercial code) and the buying and selling that is conducted by Toiya is determined by others.
商法で、自己の名をもって他人のために物品の販売又は買い入れをすることを業とする者と定義されており（b商法第551条）、問屋の行う売買は他人の計算においてなされる。