Property Tax

This article explains how Benton County, Washington property tax works and shows you how to look up your parcel, understand due dates, make secure payments, complete real estate transfers, avoid delinquency and foreclosure, and explore relief programs. You’ll also find official links to the Benton County Treasurer and Washington State pages you’ll actually use to complete tasks.

Grasp how Benton County property tax works—and who does what

Property tax in Benton County is the product of valuation, usage, and voter-approved levies. The County Assessor sets the assessed value and property use classifications. Various taxing districts—cities, school districts, fire districts, and others—apply rates to that value. The Benton County Treasurer serves as the “banker” for local governments, billing and collecting property taxes and distributing revenues to the taxing authorities. The Treasurer also collects certain special assessments and fees in the county and handles investments and other fiscal duties on behalf of county departments.

Find your parcel, confirm details, and monitor what you owe

Accurate parcel information is the foundation for getting your property taxes right. Start by confirming your parcel number, legal description, site address, ownership, and current balance. Use the county’s official search tool to:

Look up a parcel by owner name, address, or account.
Review assessment history and taxing district details.
Confirm whether payments have posted.

Visit the County’s property portal via property search to verify your records and view your tax bill before paying online. Use this to double-check that your mailing address and ownership info reflect any recent changes.

Go to the property search portal to locate your parcel and view tax details.

Use search for your parcel.

Know your due dates, weekend rules, and how postmarks work

Washington property taxes are due in two halves each year. In Benton County, the first half is due April 30 and the second half is due October 31. If April 30 or October 31 falls on a Saturday or Sunday, the statutory due date rolls to the following Monday. If you mail a payment, the United States Postal Service postmark controls timeliness—so plan for processing time through USPS to ensure your envelope is postmarked by the due date.

For the County’s official calendar and any updates that may affect a given year’s cycle, review due dates guidance from the Treasurer.

Check official property tax due dates.

Pay your Benton County property taxes with confidence

Benton County offers multiple payment channels. The right approach depends on when you pay, how you budget, and whether your parcel has any legal restrictions.

Make a secure online payment and understand checkout fees

The County’s online system supports several methods:

Credit card or any non-Visa debit card (a 2.5% vendor convenience fee applies).
E-Check (a $1 vendor transaction fee applies).
Personal Visa debit (non-business) (a $3.95 vendor service fee applies).

These service charges are authorized by state law and collected by the third-party payment vendor as allowed by RCW 36.29.190.

Pay now or schedule a payment through online payments.
Review the statutory basis for electronic payment service fees in RCW 36.29.190.

Note: If your parcel is in the foreclosure process and a Certificate of Delinquency has been filed, online payments are not permitted. See the foreclosure section below for accepted forms of payment and who is allowed to pay.

Pay by mail or in person

If you prefer not to pay online, you can mail a check or pay in person during office hours. When mailing, endorse your check to the Benton County Treasurer and include the remit coupon from your statement. Remember that timeliness is based on USPS postmark. The County also announces the availability of drop box sites and their close times for each due date; check the current guidance before relying on drop boxes, which close at 5 p.m. on the due date and may not always be in service.

See current location, mailing, and timing instructions for non-online payments at pay by mail or in person.

Reduce avoidable costs: plan for late payments and interest

If you miss a due date, state law authorizes the application of interest and penalties. Because charges depend on timing and parcel status, the precise amounts are not one-size-fits-all. If you anticipate a delay, act quickly—partial payments can reduce mounting balances, and documenting a USPS postmark by the deadline may protect you from being considered late. For edge cases around weekend and holiday deadlines or mailed payments, rely on the County’s payment questions and due date pages referenced in this guide.

Use automatic payment options to stay current

For many taxpayers, the easiest way to keep current is to automate. Benton County provides automatic payment options that help you avoid missed installments and the administrative friction of manual payments each cycle. Review any lead times for enrollment or changes and confirm which bank accounts or cards are eligible for automated debits and which vendor fees may apply.

Explore how to set up recurring payments in the County’s system on automatic payment options.

Prevent errors: verify your assessed value and ask the right questions

Your tax bill is directly tied to the Assessor’s valuation and how your property is classified for use. If you think the assessed value does not reflect your property’s condition, updates, or market comparables, start with the County’s guidance on what to review and how the value was determined. You’ll find essential steps to take before filing any appeal, such as obtaining sales data and reading your assessment notice carefully.

Learn how to review the valuation and what to do if you disagree by visiting assessed value questions.

Transfer real estate: follow Benton County’s REET process from start to finish

When property changes hands, Washington’s Real Estate Excise Tax (REET) applies, and specific paperwork must accompany your deed or other conveyance documents at the time of recording and processing:

The excise tax affidavit must be fully completed (all areas 1–7).

Four copies print when you generate the form.

Mobile/manufactured homes require a separate REET affidavit for changes in ownership.

Some special circumstances—like exemptions—require a supplemental statement.

The forms used in Benton County may not be accepted in other counties; use the county-specific materials when filing here.

Benton County provides a step-by-step local overview, while the Washington State Department of Revenue hosts the official forms you’ll need to print and complete.

Review the County’s process on real estate property transfers.
Download and complete the official state forms from Real Estate Excise Tax forms.

Protect your property: understand foreclosure and distraint procedures

Delinquent property taxes can lead to foreclosure proceedings and distraint (seizure) of personal property in certain cases. Once the Treasurer files a Certificate of Delinquency, the rules become much stricter:

Online payments are disabled for parcels in foreclosure status.

Under RCW 84.64.060, payments must be made by an interested party.

The Benton County Treasurer requires payment in full via cash or cashier’s check for parcels in foreclosure, consistent with RCW 84.64.070.

Payment methods that are acceptable for current taxes may not be accepted for delinquent parcels in foreclosure.

Because deadlines and redemption options are time-sensitive, use the County’s dedicated foreclosure guidance and reach out immediately if your parcel is at risk.

Read the County’s step-by-step foreclosure information at foreclosure and distraint.

Claim tax relief: senior, disabled, and other programs you may qualify for

Several tax relief and deferral programs in Washington can lower or postpone the property tax burden for eligible homeowners. Common pathways include:

A senior or disabled person exemption program for qualifying owner-occupants.
Deferral programs that postpone payment of property taxes (subject to program rules).
Other targeted options established by state law.

Eligibility requirements, application steps, and documentation checklists are outlined by the County. Start there to determine if you or a family member could benefit—and follow the County’s instructions to ensure your application is timely and complete.

See current qualifications and how to apply on tax relief and exemptions.

Pay the right party: mortgages, escrow accounts, and who actually remits the funds

If your mortgage servicer escrows for property taxes, they usually remit payment directly to the County Treasurer. Still, you remain responsible for confirming that the servicer pays on time and that any parcel number changes (for example, after a subdivision or boundary line adjustment) are reflected in the servicer’s records. When in doubt, check your parcel in the County’s property portal to confirm payment posting and call your servicer promptly if a payment appears outstanding as the due date approaches.

Keep records current: update addresses, names, and ownership

Tax bills and notices are mailed to the owner of record at the mailing address on file. To avoid misdirected statements:

Update your mailing address after a move or a change in your preferred correspondence location.

Ensure your name is correct after a marriage, divorce, or other legal change.

When you sell or transfer property, properly complete REET documentation and record ownership changes right away so new bills are sent to the correct owner.

The Treasurer’s website provides links to address change forms and answers to common questions about how and when updates show up on your bill.

Anticipate special assessments: irrigation billing and timing

In addition to regular property taxes, Benton County may bill certain irrigation assessments alongside the tax bill for properties within irrigation districts. Due dates for these assessments can differ, and some taxpayers transitioning from direct district billing to County collection will notice a change in how they receive statements. If you see an irrigation line on your bill, review the County’s irrigation guidance for payment timing, who to contact with service questions, and whether your mortgage company will handle those assessments through escrow.

Prepare for the annual cycle: practical checklist for Benton County taxpayers

Use this annual rhythm to stay organized and avoid last-minute scrambles:

January–February: Review your assessment notice when it arrives. If you spot discrepancies with property characteristics or use, gather documentation.

March: Confirm escrow status with your mortgage servicer. If you pay directly, set a reminder for the April installment.

April: Pay the first half by April 30 (or the next business day if it falls on a weekend). Mailed payments must carry a timely USPS postmark.

May–August: If you’re eligible for a relief or deferral program, complete your application. If you’re planning a sale, line up REET forms early.

September: Check your parcel balance in the portal and prepare for the second-half payment.

October: Pay the second half by October 31 (or the next business day if on a weekend). Keep your receipt or confirmation number.

Year-round: If you foresee a delinquency risk, contact the Treasurer promptly and review foreclosure guidance to understand options while they are still available.

Resolve common questions quickly with official County resources

Benton County’s Treasurer maintains topic-specific pages that answer frequent questions in plain language and point to the forms you need. When you need clarity on payment cutoffs, exemptions, or unique parcels (like manufactured homes), use these official sources rather than informal forums or outdated third-party summaries. The pages linked throughout this article are curated to cover the most common tax tasks in Benton County.

Departments and Offices (Property Tax)

Benton County Treasurer — Kennewick Office — 7122 W Okanogan Pl #E110, Kennewick, WA 99336 — 509-735-8505

Benton County Treasurer — Prosser Office — 620 Market St, PO Box 630, Prosser, WA 99350 — 509-786-2255

Benton County Property Tax FAQs

How are mailed or drop-box payments treated for timeliness?

For mailed payments, the Treasurer posts your account using the official USPS postmark date, so build in mailing time to ensure the envelope is postmarked by the statutory deadline. If a due date falls on a Saturday or Sunday, payment on the next business day is considered on time. When drop boxes are available, they close at 5 p.m. on the due date; confirm current availability and instructions under By Mail/In Person.

Which online payment methods are accepted and what are the vendor fees?

The Treasurer’s portal accepts credit cards and non-Visa debit cards (2.5% vendor convenience fee), e-checks ($1 vendor transaction fee), and personal non-business Visa debit cards ($3.95 vendor fee). These service charges are authorized under RCW 36.29.190 and are collected by the payment vendor. Start by searching your parcel and selecting the balance you wish to pay in Online Payments.

Why would a parcel be blocked from paying online?

When a Certificate of Delinquency has been filed, online payment is disabled. State law requires an “interested party” to pay, and the Benton County Treasurer requires payment in full by cash or cashier’s check consistent with RCW 84.64.060 and RCW 84.64.070. Review step-by-step rules, redemption timelines, and acceptable payment methods in Foreclosure and Distraint.

What documents are required when recording a real estate transfer?

Washington’s real estate excise tax (REET) affidavit must accompany deeds and other conveyances submitted for recording. The Benton County Treasurer will not accept the affidavit unless all sections (1–7) are completed, and four copies are produced. Mobile/manufactured home transfers require a separate affidavit; certain exemptions also require a supplemental statement. Local filing requirements and links to state forms are provided in Real Estate Property Transfers.

Where can I verify eligibility for exemptions or deferrals?

Benton County provides official guidance for programs such as senior/disabled exemptions and statutory deferrals. You’ll find eligibility criteria, application instructions, and answers to common issues (for example, why a bill might still show some charges after an exemption is granted) in Tax Relief/Exemptions.