投标保函是投标人向招标人提供的担保，证明投标人在中标后会履行合同义务。英文投标保函通常由投标人委托银行出具，内容涵盖保证投标人按时签约、履约、善后等事项。填写英文投标保函时，需要准确无误地完成以下内容：
明确保函类型，如投标保函、履约保函、预付款保函等。
注明招标人的名称和地址。
填写出具保函的银行名称、地址和联系方式。
标示保函金额，通常为投标价格一定比例。
注明保函的有效截止日期，超过此日期保函失效。
阐述保函的保障范围，例如：
投标人在中标后按时签订合同
投标人在履约过程中履行合同义务
投标人在合同结束后善后处理
由担保人银行声明保证：
已收到投标人书面委托
遵守保函条例
按约支付欠款或赔偿金额
担保人银行授权代表签名并加盖银行印章。
以下提供英文投标保函范本，供参考：
TO: [招标人名称]
[招标人地址]
[日期]We hereby undertake and agree that if the above named [投标人名称] (hereinafter called the "Bidder") shall fail to enter into the Contract with You (hereinafter called the "Employer") in accordance with the Tender submitted by the Bidder to the Employer for [工程名称], in the event the Bidder is selected as the successful bidder, then and in that event, we shall pay to You without deduction, reservation or protest, such sum as mentioned in the Schedule attached hereof, for the payment of which sum this Bond shall be binding upon us and our successors.
This GUARANTEE shall cease to be binding upon us upon the expiry of 30 days after the date of the Bidder's receipt of Notice from the Employer that its Tender has not been accepted by the Employer.
IN WITNESS Whereof, we have executed this Bond this [日期] at [城市].Signed and sealed for and on behalf of [银行名称]
Witness:
[见证人姓名]
[担保人银行授权代表姓名]
[银行印章]SCHEDULE
金额: [金额]
截止日期: [截止日期]
