预付款保函是怎么定义的？

山东预付款保函也称为还款保函（Repayment Guarantee），在买卖合同下还可以称为定金保函（Down Payment Guarantee）。是指担保人应合同一方当事人的申请，向合同另一方当事人开立的保函。保函规定，如申请人不履行他与受益人订立合同的义务，不将受益人预付或支付的款项退还或还款给受益人，担保人向受益人退还或支付款项。预付款保函对应的英文为“Advanced Payment Guarantee”：A contract under which the issuer undertakes to be responsible for the fulfilment of a contractual obligation owed by one person to another if the first person defaults. The issuer's obligation may be primary (as in an on-demand obligation or indemnity) or secondary (as in a guarantee). An advance payment guarantee or bond is typically used to underpin or guarantee the performance of a commercial contract, such as a contract for the sale of goods (where the buyer is the beneficiary) or a construction contract (where the employer is the beneficiary).

预付款保函在国际承包业务中使用时，是由承包人通过银行向业主提供。保证书规定，如申请人不履行他与受益人订立的合同的义务，不将受益人预付、支付的款项退还或还款给受益人，则由银行向受益人退还该款项。

预付款保函除在国际工程承包项目中使用外，也适用于货物进出口、劳务合作和技术贸易等业务。例如，在成套设备及大型交通工具的合同中，通常采用带有预付性质的分期付款或延期付款支付部分价款。在这种交易中，进口人在签订合同后，向出口人开立履约保证书，由银行保证进口人按合同规定按期支付价款，同时，出口人也向对方开立还款保证书。如出口人不能按期交货，银行保证及时偿还进口人已付款项的本金及所产生的利息。