外部原因：信用证从产生到发展，对于信用证软条款问题所产生的危害已经为广大商人和学者认识到，但是随着国际贸易的发展很多企业还是难以摆脱信用证软条款这个“陷阱”。从进出口商人之间的实力对比来看，接受软条款的出口商往往是在出口交易中某个方面处于劣势，要么是急于出口，要么是竞争对手众多，于是，降低条件，放弃原则，被动接受软条款，这样就造成了信用证机制对买卖双方当事人权利义务规定不平衡。另一方面，在过去的信用证机制下卖方的权益受到了充分的保护，而对买方的权益保护则不够，买方承担的风险则很大，在其付款之后，获得的只是一堆文件，买方要承担与货物有关的所有风险。由于在现有的信用证运行机制不能有效的保护买方的合法利益，买方就在信用证中增加软条款以保护自己。然而，在信用证中加人软条款的另一个结果是使单证相符的主动权完全掌握在买方手中。从信用证的交易实务来看，也有的出口商对信用证这种支付工具还不甚了解，对信用证软条款的识别不清楚，只看到信用证作为支付工具的便利性和可靠性，而没有看到其真正的“陷阱”条款所在，审查合同和信用证不甚严谨，对进口商存有侥幸心理，结果使自己处处被动。

External reasons: to produce letters of credit from the development of soft terms for letters of credit problems arising from the harm has been overwhelming majority of businessmen and academics to understand, but with the development of international trade many enterprises still difficult to shake off the soft terms of the letter of credit "trap." Import and export between the businessmen from the balance of power, accept the soft terms of the exporters are often in export transactions in a particular area at a disadvantage, or is eager to export, either many competitors, therefore, reduce the conditions and give up the principle of passive Accept soft terms, thus causing a letter of credit mechanism for buyers and sellers on the rights and obligations of the parties provided imbalance. On the other hand, the letters of credit mechanism in the past under the seller's rights were fully protected, while the buyer is not enough to protect the rights and interests, the risks borne by the buyer is great, in its payments, received only a pile of documents, And the buyer have to bear all risks relating to the goods. Because of the existing letter of credit can not be an effective mechanism to protect the legitimate interests of the buyer, the buyer on the increase in letters of credit in the soft terms to protect themselves. However, the increase in letters of credit were soft in terms of the results of another document that is in line with the initiative entirely in the hands of the buyer. Practice from the letters of credit transactions, and some exporters of such letters of credit payment instruments also do not quite understand, letters of credit on soft terms of the recognition not only see the letters of credit as a tool to pay the convenience and reliability , And did not see the real "trap" of the terms, the review of contracts and letters of credit less stringent, the importers have chances, with the result that all their passive.