Washington Property Tax Appeal Guide

What This Data Tells Us About Appeals in Washington

In Washington, property tax appeals are filed with the County Board of Equalization. The typical window is July 1 or within 30 days of receiving the assessment notice (whichever is later), with the deadline most commonly falling in July. Filing fees reported for this state are $0, and Lincoln Institute research plus state-reported data suggest roughly 49% of appeals result in some reduction when supported by comparable sales or documented errors.

Washington assesses at 100% of true and fair market value and reassesses annually. Senior/disabled exemptions can significantly reduce tax burden, check eligibility. Appeals are driven by the gap between a parcel's assessed value and its actual market value — the calculator below turns that gap into an annualized dollar figure at your effective tax rate. The strongest evidence is three to five arms-length comparable sales from the past six to twelve months, plus documentation of any factual errors in the assessor's record (square footage, bedroom count, finished-basement status).

This guide is for informational purposes only and is not legal or tax advice. Deadlines, filing fees, success rates, and procedures vary by county within Washington and can change year to year. Always verify the current rules with your local assessor's office — or a licensed attorney or tax professional — before filing. Source: Washington State Department of Revenue.