[Your Name] [Your Address] [City, State, ZIP] [Email Address] [Phone Number] [Date] [Recipient's Name] [Recipient's Address] [City, State, ZIP] Subject: Apology for Not Crediting Payment — [Account Number/Invoice Number] Dear [Recipient's Name], I hope this letter finds you in good health and high spirits. I am writing to express my sincere apologies for an oversight on our part that led to the non-crediting of a payment from our end. As a responsible customer, I understand the significance of timely payments and regret any inconvenience caused due to this error. I would like to provide some context and explanation regarding this oversight. On [Date of the missed payment], we made payment for [Invoice Number/Account Number] in the amount of [Payment Amount] through [Payment Method]. Regrettably, due to an internal error within our accounting system, the payment was not accurately registered in a timely manner. Upon realizing the error, our team immediately investigated the matter and identified the cause of the delay and non-crediting. We have taken immediate steps to rectify the situation and ensure that such oversights do not occur in the future. Our accounting team has promptly credited the outstanding payment to your account, and you should observe the updated balance within [Specify Timeframe]. We take full responsibility for this discrepancy and sincerely apologize for any inconvenience or disruption it may have caused. We truly value our business relationship with you and are committed to maintaining our high standards of service excellence. Rest assured, all necessary measures have been taken to prevent the recurrence of such incidents. In order to compensate for any inconvenience caused, we would like to offer you a [Discount Percentage/Service Credit] on your next invoice. Additionally, we are happy to discuss any concerns or answer any questions you may have regarding this matter. Kindly reach out to our customer service department at [Customer Service Number] or [Customer Service Email] so that we may assist you promptly. Once again, we deeply apologize for any inconvenience this incident may have caused. We value your continued trust in our services and assure you that we remain committed to providing you with the utmost satisfaction. Thank you for your understanding and patience. Yours sincerely, [Your Name]