保用单英语怎么说

保用单英语称为"Letter of Credit"，简称"L/C"。它是银行或金融机构给予的一种信用证明，表明受益人（通常是卖方）将会得到指定数额的款项。
来源: 保用单最早可以追溯到中世纪，当时商人需要信用证明来进行贸易。随着商业活动的发展和复杂性的增加，保用单也发展成为一种重要的贸易工具。
英文例句:
The supplier requires a letter of credit before they will ship the goods.
The bank issued a letter of credit to guarantee payment for the shipment of goods.
The letter of credit ensured that the seller would receive payment for the goods before shipping them to the buyer.
中文翻译:
供应商在发货之前需要一份保用单。
银行发放了一份保用单以保证货物的支付。
保用单确保卖方在发货之前收到货款。