Pay King County Property Taxes Using the Official Treasury Portal
Start here if you need to pay online, find the Seattle office address, check hours, call property tax support, use the drop box, or fix a late tax bill.
The King County Tax Collector function is handled by King County Treasury Operations. You can pay property taxes online through the official King County payment portal, by mail to King County Treasury, 201 S. Jackson St., Suite 710, Seattle, WA 98104, in person at the King County Customer Service Center at 201 S. Jackson St., 2nd Floor, or by secure drop box. For property tax customer service, call 206-263-2890. First-half property taxes are due April 30, and second-half taxes are due October 31.
King County Tax Collector Means Treasury Operations
In King County, Washington, property tax billing and payment service is handled by King County Treasury Operations. Searchers may type “King County Tax Collector,” but the official department name you will see on county pages is Treasury Operations.
When Is Your
Next Tax Deadline?
Select your state — see your exact deadline, live countdown, and whether you’re on time or already accruing penalties.
The most important thing is not the department name. It is knowing which office handles your exact problem. If you are paying a tax bill, asking whether a payment posted, mailing a check, requesting a statement, or dealing with delinquent taxes, Treasury Operations is the correct starting point. If your problem is assessed value, exemption eligibility, parcel information, or property characteristics, you may need the King County Department of Assessments or a property tax relief page instead.
Property Tax Penalty & Interest Calculator
State-specific penalty rates • Interest accrual • Tax lien deadline • Cost-of-waiting breakdown
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Tax Lien Warning
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Use Treasury Operations for payment
Use Treasury for property tax payment, tax statement questions, payment status, customer service, mobile home/personal property tax and tax foreclosure contact routing.
Use Assessments for parcel questions
If you need parcel details, account numbers, valuation change notices, property characteristics or assessment information, start with the Assessor or eReal Property Search.
Use relief/exemption pages for savings
Senior, disability, veteran, deferral and other tax relief questions should be checked through King County or Washington State property tax relief resources.
How to Pay King County Property Taxes Online
The fastest route is the official King County Property Taxes payment portal. Before you pay, confirm that the parcel or tax account number, owner information, tax year, installment and balance match your property.
Online payment is convenient, but it still needs careful checking. King County property taxes may be paid in installments, mortgage companies may submit payments close to deadlines, delinquent years may appear separately, and payment processor fees may apply. Your goal is not only to complete checkout. Your goal is to make sure the correct tax account is paid and that you keep proof.
Open the official King County payment portal
Use the official King County property tax payment portal. Check the domain before entering card or bank information. Avoid ads, copied directory pages, and unofficial payment links.
Search by parcel or tax account number
Your parcel or tax account number is usually found on your tax statement or Assessor’s Valuation Change Notice. If you do not know it, use King County’s property search tools or call the appropriate office for help.
Select the correct installment or full-year amount
King County property taxes are generally paid in two installments. Confirm whether you are paying the first half, second half, full year, current year, or a delinquent year.
Review service fees before submitting
Card or electronic payment options can include processor fees. King County does not receive the processor fee. Review the current fee shown at checkout before confirming the transaction.
Save your confirmation immediately
Download, print or screenshot the payment confirmation. Keep the parcel number, tax year, amount, payment date and confirmation number until the account shows as paid.
Official King County payment portal
Use this for real property or personal property tax bill payment. Review account details and payment fees carefully before submitting.
Open Payment PortalOfficial King County property tax page
Use this for payment options, online payment, mail instructions, in-person payment, secure drop box, and property tax information.
Open Property Tax PageKing County Tax Collector Office Address, Mailing Address and Drop Box
King County Treasury Operations is located at King Street Center in Seattle. Use the correct address based on how you are paying: online, mail, in person, or secure drop box.
Mailing Address
Use for check, cashier’s check or money order payments
In-Person Payment
King County Customer Service Center
Secure drop box warning
King County lists a secure drop box at the corner of Second Avenue and South Jackson Street, inside the security gates. Use check or money order only. Do not place cash in the drop box. The drop box availability follows the limited weekday window listed by the county, so do not assume 24-hour access.
King County Tax Collector Office Hours and Best Time to Call
The King County Customer Service Center is listed as open Monday through Friday, 8:30 am to 4:30 pm, and closed on King County holidays. Call before visiting if your tax issue is time-sensitive or complicated.
Office hours are not the same as a guarantee that every tax problem can be fixed at the counter immediately. A simple payment is different from a foreclosure payoff, mobile home tax question, personal property account, exemption issue, missing tax statement, or mortgage company delay. Calling first can save a wasted trip.
Best time to call
Call earlier in the business day, especially close to April 30 or October 31. Deadline weeks can bring more calls, in-person traffic, and payment questions.
Before you drive
Ask whether your issue can be handled in person, whether payment type is accepted, and whether you need a parcel or tax account number.
Deadline warning
Do not wait until late afternoon on the due date. Payment processor issues, traffic, lines, account lookup problems, or closed holiday schedules can create late-payment risk.
Have these ready before calling Treasury Operations
- Parcel number or tax account number
- Property address
- Tax year and installment you are asking about
- Payment confirmation number if you already paid
- Mortgage company name if escrow should have paid
- Any notice letter, delinquent notice, or foreclosure-related information
King County Property Tax Payment Options and Service Fees
King County offers several payment methods. Online and card payments can include processor service fees, so always review the current fee shown before submitting.
Online payment
Online payment is usually the fastest option. The official portal accepts electronic payment methods and displays processor fee information before you submit.
Mail payment
Mail check, cashier’s check or money order to King County Treasury. Include the property tax account number. Do not mail cash.
In-person payment
In-person payment is available at the Customer Service Center during listed hours. Card payments can include a service fee.
Fee caution
The official payment portal states that debit and credit card payments are subject to a processor service fee, with a minimum fee shown by the portal. King County does not receive that processor fee. If cost matters, compare payment options before submitting.
How to Find Your King County Parcel or Tax Account Number
You usually need a parcel number or tax account number to view and pay the correct property tax account. Check your tax statement or Assessor’s Valuation Change Notice first.
If you do not have your statement, use King County property search tools to find the parcel. Be careful with address variations, condo unit numbers, previous owner names, and recently sold properties. Paying the wrong account can create a problem that is slower to correct than spending two extra minutes verifying the parcel.
Best places to find it
- Property tax statement
- Assessor’s Valuation Change Notice
- King County property search
- Closing statement or title paperwork
- Prior-year paid receipt
Before paying, verify
- Parcel or tax account number
- Property address
- Owner or prior owner name
- Tax year
- Installment selected
- Current and delinquent balance
Micro-level search tip
If the address does not show, try fewer words, remove punctuation, use the street number with a partial street name, or search through the official property tools. For personal property tax account questions, King County lists a separate personal property contact line.
King County Property Tax Due Dates: April 30 and October 31
King County property taxes are paid in two installments. The first half is due April 30, and the second half is due October 31. If a due date falls on a weekend or King County holiday, the due date moves to the next business day.
April 30
First-half property taxes are due. Check the official portal early enough to fix account number, mortgage, mail or payment method issues.
October 31
Second-half property taxes are due. This deadline is easy to miss because it can fall near weekends, holidays, escrow timing, or year-end planning.
After the deadline
Unpaid taxes can become delinquent and may involve added costs, interest, penalties, delinquent processes, or foreclosure-related handling if not resolved.
If you did not receive a statement
Do not wait for paper mail if you know you own taxable property in King County. Use the official tax statement/account tools or call Treasury Operations. If a mortgage company pays your taxes, the statement may be handled differently, but you should still verify the account status.
What to Do if Your Mortgage Company Should Pay King County Property Taxes
King County says it is the taxpayer’s responsibility to make sure taxes are paid on time. Escrow does not equal county posting.
Mortgage companies often use processing companies and may submit payments close to the deadline. If the account still does not show as paid after the due date window, contact your mortgage company and ask for payment proof. Keep screenshots, call notes and confirmation records.
Check your escrow statement
Look for an actual tax disbursement, not just a monthly escrow charge. Escrow collection does not prove the county received payment.
Search the King County account
Confirm whether the property tax account shows paid. If it still shows unpaid after the expected period, contact the mortgage company.
Get proof from the servicer
Ask for payment date, amount, tracking number, processing company information and confirmation that the payment was sent to King County Treasury.
How to Get a King County Property Tax Receipt or Statement
A receipt or statement can matter for refinancing, selling, escrow disputes, accounting, rental property records, delinquent notices or proof that the correct installment was paid.
Online payment receipt
Save the payment confirmation page before closing the portal. Then later verify that the property tax account shows the expected paid status.
Mail payment proof
Keep a copy of the check or money order, mailing proof, and any bank record. Make sure the property tax account number was written on the payment.
Tax statement copy
If you need an informational tax statement, King County directs taxpayers to online statement tools or Treasury Operations customer service.
Receipt should show
- Parcel or tax account number
- Property address
- Tax year
- Installment or full-year amount
- Payment date
- Confirmation number
Save extra proof
- Bank/card confirmation
- Mortgage escrow proof
- Screenshot of paid status
- Mailing proof if mailed
- Name of representative if you called
King County Property Tax Exemptions, Deferrals and Relief Questions
Tax relief is not the same as paying the bill. If your question is about senior, disability, veteran or deferral programs, start with King County or Washington property tax relief resources rather than only the payment portal.
Relief programs can change, income thresholds can be adjusted, and eligibility depends on facts specific to the owner and property. If you applied for an exemption but it does not appear on your tax statement, use the official assessment/exemption contact route instead of assuming the payment office can change the bill immediately.
Senior or disability relief
Use official King County and Washington State property tax relief pages to check eligibility, application steps and income-limit rules.
Missing exemption on bill
If an exemption is missing, contact the assessment/exemption office. Keep application proof and ask whether the change applies now or to a future tax year.
Do not ignore the due date
An exemption application does not automatically remove payment deadlines. Ask the county what must be paid while the application or correction is pending.
King County Delinquent Property Taxes, Payment Plans and Foreclosure Help
If your property taxes are delinquent, do not guess the payoff amount. Search the official account, review the selected years, and call the correct King County contact if foreclosure costs or payment plans may apply.
King County payment information explains that delinquent years may be selected and must be paid in full for each selected year. For properties in foreclosure, additional costs apply, and the county directs taxpayers to call the tax foreclosure phone line for the total amount due and payment instructions.
Delinquent taxes
Check the official property tax account. Confirm the year, balance, and whether additional costs apply before paying or mailing money.
Payment plan questions
Washington rules and county options can limit hardship extensions, but payment plans may be available for delinquent taxes. Confirm directly with King County.
Foreclosure contact
King County lists a separate tax foreclosure contact line. If foreclosure status appears, call before paying because additional costs can apply.
Foreclosure phone line
For tax foreclosure questions, King County lists 206-263-2649 and TaxForeclosures@kingcounty.gov. Use this only for foreclosure-related tax matters, not ordinary current-year payment questions.
Mobile Home, Commercial Personal Property and Business Property Tax Help
Not every King County tax account is a standard real estate parcel. Mobile home, personal property, and commercial property tax questions use a separate Treasury contact route.
Personal property contact
For mobile home, personal property and commercial property tax questions, King County lists 206-263-2844 and Treasury.PersonalProperty@kingcounty.gov.
Online payment limitation warning
Personal property accounts can have different online payment behavior from real property accounts. Read the portal instructions carefully before trying to pay the full year.
Why This King County Tax Collector Page Is Built Like a Tool
A thin directory page gives one phone number. A useful taxpayer page helps the user finish the task: pay, call, mail, visit, use the drop box, print proof, or fix a late account.
First screen solves the job
Users see payment, address, office hours and late-bill help immediately, without reading a long intro.
Wrong office confusion is reduced
The page separates Treasury payment help from assessment, exemption, mortgage, personal property and foreclosure issues.
Real payment details are included
Mail address, drop box warnings, payment fees, due dates, receipts and escrow problems make the page more useful than a basic listing.
King County Treasury Operations Map and Visit Reminder
King County Treasury Operations and the Customer Service Center are located at King Street Center, 201 S. Jackson St., Seattle, WA 98104. Use the map for directions, then confirm current service details before visiting.
Bring if visiting
- Property tax statement or parcel number
- Payment method accepted by the county
- Photo ID if required for your request
- Payment confirmation if following up
- Mortgage or escrow documents if relevant
Call before parking
- Confirm the Customer Service Center is open.
- Ask whether your payment type is accepted.
- Ask whether your account needs personal property or foreclosure routing.
- Ask whether a receipt is available for your payment method.
Official King County Property Tax Links
Use official King County and Washington State resources before relying on third-party directory pages. Payment links, fees, due dates, office hours and foreclosure instructions can change.
King County Tax Collector FAQ
These answers focus on payment, address, office hours, phone numbers, receipts, escrow, fees, exemptions, delinquent taxes and the difference between Treasury and the Assessor.
Best Way to Use This King County Tax Collector Guide
Use the official King County payment portal first, confirm your parcel or tax account number, select the correct installment or tax year, review any service fee, then save your confirmation. For customer service, call 206-263-2890. For personal property and mobile home tax questions, call 206-263-2844.
Mail payments to King County Treasury, 201 S. Jackson St., Suite 710, Seattle, WA 98104. In-person payments are handled at the King County Customer Service Center at 201 S. Jackson St., 2nd Floor, during listed weekday hours. Always verify current office closures, service fees, drop box access and account status through official King County pages before paying.
Editorial note and official-source warning
This is an independent TaxCollectors.org guide for King County, Washington taxpayers. It is not the official King County Treasury Operations office, King County Assessor, Washington Department of Revenue, mortgage servicer, legal adviser or tax adviser.
Before paying, mailing documents, visiting an office, relying on a drop box, disputing a value, applying for relief, or handling delinquent taxes, verify current details directly through official King County and Washington State sources. Payment methods, processor fees, office closures, holiday schedules, drop box access and account status can change.
Official source shortcuts: King County Property Taxes, King County Payment Portal, Treasury Operations, and Property Tax FAQ.