The Benton County Treasurer's Office has CLOSED all the drop boxes outside both the Prosser Courthouse and the Benton County Administration building in Kennewick, and Richland City Hall for property tax payments. The drop boxes are designed for property tax payments made by check. (NO CASH payments) Drop boxes are now CLOSED (All Locations)

The Benton County Treasurer's Office has completed the certification of the 2026 taxes. Please take some time to read the Tax Certification Letter. The tax statements are expected to be mailed by the end of February. If you have not received your statement by the middle of March, please give our office a call. 2026 Tax Certification Letter