Subject: Request for Signature on Returned Check — Urgent Response Required [Your Name] [Your Address] [City, State, ZIP] [Email Address] [Phone Number] [Date] [Recipient's Name] [Recipient's Address] [City, State, ZIP] Dear [Recipient's Name], I hope this letter finds you in good health. I am writing to inform you regarding a check that was recently returned to me due to a missing signature on your end. This issue requires your immediate attention to rectify the matter. The check, numbered [Check Number], was issued by me on [Date] in the amount of [Check Amount] and was made payable to [Payee's Name]. Upon receiving the returned check from my bank, I discovered that your endorsement signature was missing. Without a valid signature, the bank was unable to process the check, which has caused unnecessary inconvenience and delays. As a matter of utmost importance, I kindly request that you sign the enclosed copy of the returned check provided with this letter. Please carefully review the check and ensure that your signature is clearly and legibly written across the designated area on the back of the check. Once you have affixed your signature, please promptly return the check to me using the enclosed self-addressed envelope or any alternative reliable mailing method. Additionally, I urge you to include a photocopy of a valid identification document, such as a driver's license or passport, to validate your signature and avoid any further complications. Please understand that your immediate attention to this matter is crucial to resolve this issue efficiently. I kindly request that you return the signed check within [a reasonable timeframe, e.g., 10 business days] from the date of this letter. In the event that you cannot locate the original check or have any concerns or questions, please contact me at [Your Phone Number] or via email at [Your Email Address]. I am more than willing to assist you in any way possible to ensure a prompt resolution. Thank you for your immediate attention to this matter. I genuinely appreciate your cooperation and understanding. I trust that this oversight will be resolved promptly, and I look forward to receiving the signed check in due course. Yours sincerely, [Your Name]