Dear [Customer's Name], We hope this letter finds you well. We are writing to sincerely apologize for the accounting error that occurred on your recent purchase with [Company Name]. We take full responsibility for this mistake and want to assure you that we are working diligently to rectify the situation as quickly as possible. At [Company Name], we strive to provide top-notch customer service and maintain the highest standards in our accounting practices. Unfortunately, on this occasion, an oversight was made that resulted in an error in your financial transaction. We deeply regret any inconvenience or confusion this has caused you. Rest assured that we have identified the issue and are implementing immediate measures to ensure it does not happen again in the future. Our accounting team is working tirelessly to resolve the error, and we will update you personally once the correction has been made. We understand the importance of accuracy and accountability, and we want to assure you that this incident is being taken very seriously. Furthermore, we want to emphasize that your trust and satisfaction are of utmost importance to us. We appreciate your understanding and patience while we rectify this situation. In light of this error, we would like to offer you a [discount/credit/refund] on your next purchase as a gesture of goodwill. Additionally, we encourage you to reach out to our customer support team at [contact information] if you have any further questions or concerns regarding this matter. We are more than willing to assist you in any way we can. Once again, we apologize sincerely for the accounting error, and we thank you for bringing it to our attention. We value your continued patronage and assure you that we are committed to providing you with an exceptional customer experience moving forward. Thank you for your understanding and cooperation. Sincerely, [Your Name] [Your Position] [Company Name]