预付款保函（advance payment guarantee）承包人要求银行向业主(发包人) 出具的保证业主所支付的工程预付款用于实施项目的一种信用函件。投标人在中标后签订的合同中规定，承包人委托银行向业主出具的由业主按合同规定向承包人支付一笔工程预付款，及时用于实施项目的保证函件（即A委托B向C作出担保，担保内容是C按合同约定向A支付的预付款确实在用于项目的实施）。担保银行应为业主所接受。如承包人不履约，业主可凭保函向担保银行索赔。
应委托人要求，我们(填入银行名称) 在此不可撤回地承担在我方收到你方书面要求及说明下列情况的书面声明后，向你方---受益人/雇主支付总数不超过 (填入“保函金额”，用文字表示： )的一笔或多笔款额：
Name and address of Beneficiary (whom the Contract defines as the Employer).
We have been informed that (hereinafter called the “Principal”) is your contractor under such Contract and wishes to receive an advance payment, for which the Contract requires him to obtain a guarantee.
At the request of the Principal, we (name of bank) hereby irrevocably undertake to pay you, the Beneficiary/Employer, any sum or sums not exceeding in total the amount of (the “guaranteed amount”, say: ) upon receipt by us of your demand in writing and your written statement stating:
(a) that the Principal has failed to repay the advance payment in accordance with the conditions of the Contract, and
(b) the amount which the Principal has failed to repay.
This guarantee shall become effective upon receipt [of the first instalment] of the advance payment by the Principal. Such guaranteed amount shall be reduced by the amounts of the advance payment repaid to you, as evidenced by your notices issued under sub-clause 14.6 of the conditions of the Contract. Following receipt (from the Principal) of a copy of each purported notice, we shall promptly notify you of the revised guaranteed amount accordingly.
Any demand for payment must contain your signature(s) which must be authenticated by your bankers or by a notary public. The authenticated demand and statement must be received by us at this office on or before (the date 70 days after the expected expiry of the Time for Completion) ____________ (the “expiry date”), when this guarantee shall expire and shall be returned to us.
We have been informed that the Beneficiary may require the Principal to extend this guarantee if the advance payment has not been repaid by the date 28 days prior to such expiry date. We undertake to pay you such guaranteed amount upon receipt by us, within such period of 28 days, of your demand in writing and your written statement that the advance payment has not been repaid and that this guarantee has not been extended.
This guarantee shall be governed by the laws of and shall be subject to the Uniform Rules for Demand Guarantees, published as number 458 by the International Chamber of Commerce, except as stated above.
Date ____________ Signature(s)