在国际贸易和商业合作中，及时有效的沟通是确保业务顺利进行的关键。当涉及到款项支付时，适时地发出催款函显得尤为重要。以下是一份精心设计的商务英文催款函模板，旨在帮助您以专业且礼貌的方式提醒客户支付未结清的款项。

Subject: Friendly Reminder on Outstanding Payment

Dear [Customer's Name],

I hope this message finds you well. We are writing to kindly remind you of the outstanding payment for our recent transaction, which is due by [Payment Due Date].

We value our business relationship and appreciate your continued support. However, as of today, we have not yet received the payment for the amount of [Amount] related to the invoice number [Invoice Number].

Please let us know if there are any issues or concerns regarding this payment. If everything is in order, we would greatly appreciate it if you could settle this balance at your earliest convenience.

If you require any further information or documentation, please do not hesitate to contact us. We are here to assist you with any questions you may have.

Thank you for your attention to this matter. We look forward to resolving this promptly and continuing our successful partnership.

Best regards,

[Your Full Name]

[Your Position]

[Your Company Name]

[Your Contact Information]

此模板以礼貌和专业的语气撰写，既表达了对客户的尊重，又清晰地传达了付款请求的信息。通过这种方式，您可以有效地促进款项的回收，同时保持良好的客户关系。希望这份模板能为您的工作带来便利！