Section 28-5621 - Failure to report or pay tax; penalties; interest; transmittal dateA. Except as otherwise provided in this subsection, if a supplier fails to submit the monthly report to the director on or before the twenty-seventh day of the month, fails to submit the data or information required under this article in the monthly report or fails to pay the amount of taxes due when payable, the supplier shall pay interest on the unpaid tax at the rate of one per cent per month or portion of a month from the due date until paid and a penalty of five per cent shall be added to any tax not paid on or before the day prescribed for the payment of the tax. A supplier is not subject to the five per cent penalty on transactions reported within ninety days after the due date if the supplier has paid at least ninety-nine and one-half per cent of the actual tax liability for the month by the due date.B. In addition to the penalty provided by subsection A, a person who fails to file a report required by this section when due shall pay an additional penalty of twenty-five dollars.C. If a report or remittance required by this article is transmitted through the United States mail and is not received by the director until after the date on which the report is required to be filed or the payment was required to be made and if the envelope in which the report or remittance is enclosed has a post office cancellation mark dated on or before that date, on receipt of the envelope, the director shall treat the report or remittance as if it had been received on the required date.