An order letter is written by the buyer, asking the seller to provide specified quantity of goods on the terms agreed upon by both parties or services. After the exchange of a number of letters, the buyer finally places an order. It should be noted that an order letter shows the buyer’s wish to buy. Like the non-firm offer, it is not legally binding unless it is accepted and confirmed by the seller, usually in the form of a sales contract or sales confirmation.

An order letter is usually made up of three parts. The opening of the letter refers to previous contacts, such as exchanged letters, phone calls, etc. Following the opening, the buyer should state clearly all the terms of transaction, including description of the commodity, quantity, unit price, total amount, price terms, package, delivery terms, port of destination, terms of payment. Finally, the buyer should end the letter to express courtesy.

Nowadays, many companies provide specially-designed order forms. When the buyer wants to place an order, he (she) only needs to fill in the form. It is much easier than writing an order letter.

订购函是买卖双方经过反复磋商，买方接受交易条件后，向卖方订购所需货物或服务的信函。订购函一般包括商品名称、商品规格、数量、价格、结算方式、交货日期和地点等。订购函可由三部分组成。首先，买方可提及双方之前的沟通，并表达订购愿望。接下来，买方需详细说明订购货物的商品名称、商品规格、数量、价格、结算方式、交货日期和地点、运输方式等，最后可以要求对方回函确认。