King County tax records are free to search online through two county portals: the Assessor’s eReal Property system, which shows assessed values, property characteristics, levy codes, and sales history, and the Treasury’s Property Tax Information system, which shows current balances, due dates, and payment history.1King County. King County Assessor Neither requires an account. The fastest lookups use a parcel number, but address and complex-name searches work too.
What You Need Before You Search
The most reliable way to pull up a record is by parcel number. Every lot in King County has a unique parcel number, sometimes called a tax account number, printed on your annual tax statement and on your deed. Using it avoids the problems that come with address or name searches, where common street names and shared surnames can return dozens of unrelated results.2King County, Washington. Property Research
If you don’t have the parcel number handy, the county’s search tools also accept street addresses and condominium or apartment complex names. Address searches work well when the address is distinctive, but they can trip you up in areas where streets share names across different cities within the county. When in doubt, cross-reference the result against the property’s legal description or map location before relying on the data.
For a more visual approach, the county’s iMap tool and Parcel Viewer let you click directly on a map to pull up property information. These help when you’re trying to identify a property you’ve driven past but don’t have an address for, or when you want to see how a parcel sits relative to roads and waterways.2King County, Washington. Property Research
What a King County Tax Record Shows
Each record ties a specific parcel to its financial obligations for the year. It starts with two valuation figures: the assessed value, which is what the county says the property is worth based on market conditions, and the taxable value, which is what’s left after any exemptions or deferrals are subtracted. The taxable value is what your bill is calculated from, so the gap between these two numbers matters if you qualify for a relief program.
The record also separates the value of the bare land from the value of any structures on it. That split matters during appeals, because the county might have the land value right but the building value wrong, or the reverse. Each property is assigned a levy code identifying the specific combination of taxing districts that apply at that location, including the school district, fire district, library district, and others.
Within eReal Property, the Tax Roll section breaks down your bill by individual taxing district, so you can see exactly how much goes to schools, how much to the county general fund, and so on. The Payment History tab on the Treasury side gives you a chronological log of every payment credited to the account. If you’re buying a property and want to confirm the seller is current on taxes, this is the fastest way to check without waiting for a title company. Unpaid property taxes create liens that transfer with the property, so that payment trail is worth reading carefully.
Reading the Levy Rate
Your total tax rate on the record is expressed per $1,000 of assessed value. If your assessed value is $200,000 and your levy rate is $13 per $1,000, your annual tax bill is $2,600.3King County, Washington. City Tax Comparison for 2025-2026
Because each property sits within a unique combination of overlapping districts, two homes a few blocks apart can carry noticeably different tax rates. The levy code on your record tells you which districts you’re paying into. If you were recently annexed into a city or a new fire district formed in your area, your levy code and rate will change to reflect that. Voter-approved “levy lid lifts” can also reset a district’s base above what the state’s standard 1% annual cap would allow,4Washington State Legislature. Washington Code RCW 84.55.005 which shows up on your record as a higher rate attached to that district.
Checking Payment Status and Deadlines
King County property taxes are due in two installments. The first half is due April 30, and the second half is due October 31. If your total annual tax is less than $50, the full amount is due with the first installment on April 30.5Washington Department of Revenue. 2026 Property Tax Calendar Due Dates The Treasury portal will show whether each installment has been paid, whether interest has accrued, and whether any balance remains.
If a record shows a delinquent balance, the interest and penalty rules depend on the property type. Residential parcels with four or fewer units, including manufactured homes, accrue interest at 9% per year with no additional penalties. All other property, including commercial buildings and residential parcels with five or more units, accrues 12% per year, plus a 3% penalty if the delinquent amount isn’t paid by June 1 and an additional 8% penalty if it remains unpaid by December 1.6Washington Department of Revenue. Legislative Changes to Delinquent Property Taxes A commercial owner who ignores a bill all year ends up facing 12% interest plus 11% in combined penalties, so a record showing early-year delinquency on commercial property is a different situation than the same gap on a single-family home.
When You Need an Official or Certified Record
Most people will never need anything beyond what the online portals provide. Certain situations, though, like estate settlements, litigation, or complex title disputes, call for certified tax statements that a screenshot or printout can’t replace. Those must be requested through the King County Treasury or the Department of Assessments.
Washington’s Public Records Act governs these requests. After you submit a request through the county’s public records portal or by written notice, the agency has five business days to respond, either by providing the records, giving you a time estimate, or seeking clarification if the request is unclear.7Washington State Legislature. WAC 44-14-04003 – What Constitutes a Reasonable Time to Respond to a Request Actual delivery can take longer depending on the age and complexity of the records.
Fees are modest. If the county hasn’t set its own per-page rate, state law caps photocopies at 15 cents per page and scanned documents at 10 cents per page. Electronic file transfers cost as little as 5 cents per four files uploaded. The county can also charge a flat fee of up to $2 for any request when the itemized costs would exceed that amount.8Washington State Legislature. Washington Code RCW 42.56.120 Be specific about the years and document types you need. Vague requests slow the process down and can trigger back-and-forth clarification that adds weeks.
If the Record Shows an Overvaluation
If a lookup leaves you convinced the Assessor’s office overvalued your property, you can appeal to the King County Board of Appeals and Equalization. The deadline is July 1 of the assessment year or 60 days from the date printed on your valuation notice, whichever gives you more time.9King County, Washington. How to Appeal a Property Tax Assessment Miss that window and you’re stuck with the valuation for the year.
The statutory baseline is 30 days from the date the notice was mailed or transmitted electronically, but King County’s legislative authority has extended that to 60 days.10Washington State Legislature. Washington Code RCW 84.40.038 Valuation notices are typically mailed between May and November, so your specific deadline depends on when yours arrives. The strongest appeals come with evidence: recent comparable sales in your neighborhood, a professional appraisal, or documentation of physical problems with the property that the assessor may not have accounted for. If the Board rules against you, you can escalate to the Washington State Board of Tax Appeals.
Separately, if you’re a senior, a person with a disability, or a qualifying veteran, King County administers an exemption program that can substantially reduce the tax bill on a primary residence; the senior exemption portal walks through eligibility and application.11King County. Senior Exemption Portal That’s a separate process from reading or correcting the record itself.