在国际贸易中，及时收回货款是企业维持正常运营的重要保障。当客户未能按时支付款项时，适时地发送一封礼貌而专业的催款函显得尤为重要。以下是一封外贸英语函电催款函的范例，供参考：

Dear [Customer Name],

I hope this message finds you well. I am writing to kindly remind you of the outstanding payment for your recent order under our agreement, Order No. [Order Number]. The total amount due is [Amount], which was originally agreed to be paid by [Original Due Date].

We understand that delays can occur due to unforeseen circumstances, and we are always willing to work with our valued clients to resolve any issues. However, to ensure smooth business operations, we would appreciate it if you could settle the balance at your earliest convenience.

If there are any concerns or challenges regarding the payment, please do not hesitate to contact us so that we may discuss possible solutions together. Your prompt attention to this matter will help maintain our ongoing business relationship.

Thank you for your understanding and cooperation. We look forward to resolving this matter swiftly and continuing our successful partnership.

Best regards,

[Your Full Name]

[Your Position]

[Company Name]

[Contact Information]

此模板旨在保持专业性和友好性，同时明确表达催款请求。根据具体情况调整信件中的细节部分（如订单号、金额和日期等），以确保信息准确无误。希望这封函件能够帮助您有效地处理收款事宜。