The second half of real estate and mobile home taxes must be paid by April 1st. The taxes were due March 1st, and starting April 2nd a penalty will be added. The penalty is 1.5% per month, rounded to the nearest whole dollar, with a $1 minimum per parcel. Payments can be made online at IowaTreasurers.org, in person at the Washington County Treasurer’s Office in the courthouse, or by mail. Payments must be accompanied by statement coupons. Any taxes that are still unpaid on May 31st will be advertised as delinquent. And then any that remain unpaid on June 17 will be offered at the annual tax sale.