Subject: Apology for Not Crediting Your Payment from a Prompt Payer [Your Name] [Your Address] [City, State, ZIP Code] [Email Address] [Phone Number] [Date] [Recipient's Name] [Recipient's Designation] [Company Name] [Company Address] [City, State, ZIP Code] Dear [Recipient's Name], I am writing this letter to extend my sincerest apologies for an oversight on our part regarding the recent payment you made to [Company Name]. We regret to inform you that your payment was not credited to your account promptly, and we apologize for any inconvenience or frustration it may have caused. Our records indicate that you are typically a prompt payer, and we greatly value your commitment to meeting your financial obligations. Please rest assured that this incident does not reflect our usual standards of efficiency and accuracy in processing payments. We understand the importance of promptly crediting payments and take full responsibility for this error. To rectify the situation, we have investigated the matter thoroughly and have identified the source of the problem within our billing system. We have taken the necessary steps to ensure that such a lapse does not occur in the future. Additionally, we have credited the outstanding payment to your account with a sincere apology for the delay. We understand that you rely on accurate and timely account information for your records and financial planning, and we deeply regret any inconvenience or disruption this may have caused for you. We are committed to serving our customers diligently, and we appreciate your understanding and patience as we resolve this issue. Moving forward, we will be closely monitoring our payment processing procedures to avoid similar situations in the future. Should you encounter any additional problems or have any concerns, please do not hesitate to contact our customer service department at [Customer Service Number] or via email at [Customer Service Email Address]. Our dedicated team is ready to assist you in any way possible. Once again, we sincerely apologize and thank you for your patience and understanding regarding this matter. We value your continued trust in our company and assure you that we will make every effort to prevent this error from recurring. Thank you for bringing this to our attention, and we look forward to providing you with excellent service in the future. Yours sincerely, [Your Name]