The first installment of Johnson County property and mobile home taxes was due on Friday, Sept. 1, 2023. Payments must be delivered to the Treasurer’s Office, paid online, or postmarked by Oct. 2, 2023, to avoid a 1 ½ percent monthly penalty that will begin on Tuesday, Oct. 3, 2023.

In-person payments must be made at the Treasurer’s Office, located on the first floor of the Johnson County Administration Building, 913 S. Dubuque St. in Iowa City. Hours are Monday through Friday, 8 a.m. to 5 p.m.

If paying by mail, the stub portion of the tax statement must be submitted with the payment. Payments must be mailed to the Johnson County Treasurer, PO Box 2420, Iowa City, IA 52244-2420. Payments postmarked by Oct. 2, 2023, will be considered paid on time and no interest will be charged. The U.S. Postal Service postmark is the only date recognized for date of mailing. The date written on a check or a business metered date cannot be accepted as proof of the mailing date. Residents who would like a receipt must include a self-addressed stamped envelope with their payment.

To make an online payment, visit You can pay with an e-check; debit card; or VISA, MasterCard, Discover or American Express credit card. Those methods of payment, whether online or at the Treasurer’s Office, are subject to a convenience fee.

County Treasurers collect property taxes on behalf of all jurisdictions in the county and then distribute the taxes collected to the other jurisdictions, including the property owner’s city of residence, school district and other taxing bodies in the county.

Questions about payments should be directed to the Treasurer’s Office at 319-356-6087 or [email protected].  Additional information about property taxes is available at