The current year first half taxes must be paid by April 30 or the entire tax amount becomes delinquent. Interest and penalty amounts on delinquent first half taxes are calculated on the entire year's tax amount.
Interest = 1% per month on the full amount due (from month of delinquency to month of payment)
Penalty = 3% (current year tax only) on amount unpaid on June 1
8% (current year tax only) on amount unpaid on December 1