2026 Property Tax Due Dates
April 30
First half
October 31
Second half
Payment Methods
Online, Mail, In-Person
Island County Treasurer
Phone
(360) 679-7302Mailing Address
P.O. Box 699, Coupeville, WA 98239
Office Hours
How to Pay
Online
Pay using credit card or e-check
By Mail
Mail check payable to Island County Treasurer — P.O. Box 699, Coupeville, WA 98239
In Person
Visit the Treasurer's office — 1 NE 7th St., Suite 111, Coupeville WA 98239, Mon-Fri 8am - 4:30pm
Other Counties in Washington
About Island County
Island County is a county located in the U.S. state of Washington. As of the 2020 census, its population was 86,857. Its county seat is Coupeville, while its largest city is Oak Harbor.
Source: Wikipedia — content available under CC BY-SA 4.0
Related Resources
Get Deadline Reminders
We'll email you 14 days before your property taxes are due.
Due dates shown are for reference only. Contact your county treasurer's office to confirm official deadlines before making payments.