Due to the grace period, they become delinquent on the sixth business day after they were due. The 2nd installment option is forfeited and the entire bill becomes due if an installment date is missed. Interest begins accruing at 1.5% per month on the unpaid balance, beginning the month after the due date. For instance, if a first installment is missed, the next day after the grace period, one and a half % interest is added to the bill. In March it increases to three %. Interest continues to accrue until the bill is paid in full. Additional applicable fees may be applied. Please contact the Portage County Treasurer's office for a final payoff amount.