Pay Property taxes in Cowlitz County, Washington with this online service.


When are my property taxes due?

The annual due dates are April 30 and October 31. RCW 84.56.020 A timely 1st half payment must have a postmark of April 30. A timely 2nd half payment must have a postmark of October 31. RCW 01.12.070

How do I pay my property taxes?

In Office: We can accept checks or cash in office. During closed or busy office hours, you can use the drop box located outside of the Treasurer's Office doors. By Mail: Send a check in to: Cowlitz County Treasurer 207 N 4th Ave Kelso, WA 98626 By Credit Card: Please visit or call 1-855-857-3624. Credit/debit card payments are also acceptable in the Treasurer's Office. All checks must be made payable to Cowlitz County Treasurer. If the payment coupon is not included please be sure to include the parcel number or account number. Your payment must be postmarked by the due date to be considered timely, otherwise interest and/or penalty will apply RCW 01.12.070.

Can I pay just a portion of the taxes due?

Unless specifically stated under RCW 84.56.020, we cannot accept a portion of taxes.