noun
Refers to the person who places an order, typically in a commercial or business context.
注文者が商品を受け取るまで、支払いは保留されます。
Payment is held until the orderer receives the goods.
注文者の名前と住所を確認してください。
Please confirm the name and address of the customer.
購入者 is a more general term for 'purchaser', while 注文者 specifically refers to someone who places an order.
Compound of 注文 (order) + 者 (person).