King County property tax due dates, how to pay and appeal

The second half of King County's 2026 property taxes is due Monday, November 2, 2026, not Saturday, October 31. The King County Treasury's property tax page carries the line "Second half of 2026 property taxes are due November 2". As of October 2026 the usual dates are April 30 for the first half and October 31 for the second, and the county moves either one to the next business day when it lands on a weekend or King County holiday. Enumclaw parcels in King County pay on the same dates, inside the city or out, because the county treasurer collects the city, school and fire district taxes on one bill.

The usual second-half date, October 31, is a Saturday in 2026, and what happens to an owner who misses it changed in 2023. A house or other residential property of up to four units pays 9 percent a year and no penalties. Everything else pays 12 percent a year plus penalties. The county mails one statement a year, sends no reminder you did not ask for, and by its own account cannot grant a hardship extension.

When are King County property taxes due?

King County property taxes are due in two halves, on April 30 and October 31. The Treasury's property tax FAQ says so, and the dates come from state law, RCW 84.56.020, which applies in every Washington county. The October half is an option only when the total bill is $50 or more and the first half was paid by April 30.

The statement comes once a year. The Treasury says statements are mailed in mid-February, with no more before the deadlines unless asked. It offers email or text reminders about 30 days ahead, with a sign-up on its property tax page.

What if October 31 is a Saturday?

Then the deadline is Monday, and in 2026 that is the case. The Treasury's FAQ puts the rule in one sentence: "If one of these dates falls on a weekend or King County holiday, taxes are due the next business day." Washington has a general version for payments to local governments, RCW 1.12.070, which treats a remittance due on a Saturday, Sunday or legal holiday as timely if made on the next business day.

The FAQ's late-payment answer still names October 31 and November 1 in general terms, but its weekend rule sits on the same page and the banner names November 2, so a payment made online or postmarked by Monday, November 2 is on time under the county's stated rule. To leave no doubt at all, pay by Friday, October 30.

The rule keeps working after 2026. By this desk's calendar arithmetic, not a county announcement: April 30, 2027 is a Friday and stays put, October 31, 2027 is a Sunday so the second half would move to Monday, November 1, 2027, and April 30, 2028 is a Sunday so the first half would move to Monday, May 1, 2028. Check the Treasury's banner first.

How do I pay King County property tax online?

Online payment runs through the county's eCommerce system, and you need your parcel or tax account number, printed on the statement and the Assessor's valuation notice. Credit cards, debit cards and electronic checks, which the FAQ calls eChecks, are all accepted.

There is a fee, and the county does not get it. As of October 2026 the FAQ puts the eCheck fee at a flat $0.55, the card fee at 2.35 percent with a minimum of $2, and the international card fee at 3.95 percent with the same minimum. State law does not let the county absorb processing costs for electronic property tax payments, the FAQ says, and the payment processor keeps the fee. On a $2,700 half-year payment the card fee works out to about $63, against $0.55 for an eCheck.

The deadline is exact. The FAQ treats an online payment made after midnight on the due date as late, with delinquency charges.

Can I pay by mail, at a drop box or in person?

All three work. By mail, send a check payable to King County Treasury to 201 S. Jackson St., Suite 710, Seattle, with the parcel or account number written on it. The FAQ says it must be postmarked by the due date and needs no statement if the amount is right. Do not send cash.

A secure drop box marked "Treasury" sits inside King Street Center at Second Avenue and South Jackson Street in Pioneer Square. It takes checks and money orders, not cash, and is open from 8:30 a.m. until 4:30 p.m. on weekdays that are not King County holidays. The Customer Service Center upstairs keeps the same schedule and takes cash, card or check. Nobody can pay by phone, though staff will talk you through the online steps.

For a mailed payment with no readable postmark, the statute is more forgiving than the county's page: an envelope with no discernible postmark date that arrives within three business days of October 31 is not delinquent. The sources opened here do not say how that count works when the due date moves, so an unpostmarked envelope is a bad bet.

Pioneer Square is about 40 miles from Enumclaw, about an hour by a mapping service's estimate, and nobody needs to make the drive.

What happens if I pay late?

A late second half starts costing money the day after the due date, and the cost depends on the kind of property. Under RCW 84.56.020, since January 1, 2023, delinquent taxes on residential real property of four or fewer units per parcel, manufactured and mobile homes included, carry interest at 9 percent a year, and the statute bars penalties on that property. Everything else carries interest at 12 percent a year. For nonresidential property, residential buildings of more than four units and personal property, the statute adds a penalty of 3 percent on the tax delinquent on June 1 and an additional 8 percent on the delinquent amount on December 1.

Interest is computed monthly, which is what the county means by monthly late charges. The county's eCommerce tool shows the exact amount for any account.

Extensions are the part owners miss. The Treasury says that by state law "extensions cannot be granted due to hardship or any other extenuating circumstances." The statute does let a county treasurer grant extensions during a declared state of emergency.

What does a late month cost on an Enumclaw house?

On the median Enumclaw house, about $20. The site's Enumclaw property tax explainer reports the median 2026 bill at $5,404.04, from the Assessor's figures. Half is $2,702.02, and 9 percent a year is 0.75 percent a month, about $20.27 on the half. That is this desk's arithmetic, assuming a straight monthly share, and the county's tool has the official number. The same bill carries the line for the elected fire commissioners, whom the 911 explainer covers, and the school district lines whose bond history is in the enrollment count day story.

A parcel in another county is collected by that county's treasurer, with its own payment methods. The April 30 and October 31 dates are state law, but how a weekend is handled is that treasurer's call.

How do I appeal my King County property tax assessment?

You appeal the value, not the bill, and the clock starts when the Assessor mails your valuation notice. The Board of Equalization says notices go out between May and November, and defines the assessment year as the one before the tax is payable. A notice mailed in 2026 therefore sets the taxes payable in 2027, and an appeal filed in autumn 2026 cannot lower the November 2, 2026 bill.

The deadline has two statements. The county's how-to-appeal page says: "Your petition must be filed online or postmarked to the BOE office by July 1 of the assessment year, or within 60 days from the mailing date printed on your valuation notice." The statute, RCW 84.40.038, lists July 1, thirty days after the notice, or a limit of up to sixty days that the county sets, whichever is later. Read together, a notice mailed in September gives you the later date, not a July 1 that has passed. The board says to look up your parcel to see its due date, so do that. A late petition can be waived for good cause, such as serious illness or a documented postal delay.

File through eAppeals, which is only for real property, or by mail to Room 1222 at 516 Third Avenue in Seattle. Email is not accepted, and each parcel needs its own petition. The case has to be about market value: "personal hardship, amount of tax, and other matters unrelated to market value cannot be considered," the board says, and the Assessor is presumed correct. The board suggests calling the Assessor's office first, at 206-296-7300, since a simple error may need no appeal.

Who can help with a property tax problem?

The county's Tax Advisor, at 206-477-1060, advises taxpayers on property tax matters and says it specializes in appeals. By the county's account it is independent of the Assessor and the Board of Equalization. For residential properties, the county's appeal pages say it can help find comparable sales and prepare an appeal. It cannot reduce your value or lower your bill. The county pages do not say whether the service costs anything.

Before you pay

Check three things before the deadline. First, the Treasury's property tax page, which carried the November 2 date as of October 2026. Second, your lender: if a mortgage company pays your taxes, the FAQ says the owner is still responsible, and to call the lender if the payment does not show ten days after the due date. Third, your bank, which the county calls the easiest way to confirm a payment went through, because the county sends no notice when one does not post.

Election Day is the next day, Tuesday, November 3, and the November ballot dates guide covers what a voter can still do.