Penalty for Late Payments Interest at an annual rate of 14% is computed daily and is assessed to all payments received after the original due date. Postmarks are not acceptable; payments must be received by the due date to avoid interest and penalties. All unpaid real estate and personal property bills generate a Demand Bill which includes a $10 Demand fee and interest, and is payable in 14 days from the date of issue. All unpaid real estate and personal property bills are sent to the deputy collector for collection and additional fees are incurred.