Washington B&O Tax Basics and 2026 Rates

Washington State does not have personal or corporate income tax, but most businesses still pay the Business and Occupation (B&O) tax on their gross revenue from activities within the state. For small business owners and contractors in Richland, Kennewick, Pasco, and the Tri-Cities, understanding the 2026 B&O tax rules is essential because it affects pricing, cash flow, and profitability.

This guide explains the key aspects of Washington B&O tax in 2026, including current rates, classifications, credits, filing requirements, and special considerations for contractors. Insight Business & Accounting Solutions, a CPA firm based in Richland, provides this practical resource to help business owners comply and plan effectively.

Quick overview: Washington B&O tax basics and 2026 rates

Washington's Business and Occupation tax, or B&O tax, is a gross receipts business tax, meaning it applies to total revenue or gross proceeds from business activities in the state without deductions for expenses like labor, materials, or overhead; Washington is often viewed as tax-friendly because it has no state personal or corporate income tax. This distinguishes it from federal income tax, which is based on net profit, and retail sales tax, which is collected from customers and remitted separately, though many companies still have other taxes to track and pay taxes on as required.

The tax rate depends on your business activity, called a tax classification, so a business owner needs to understand Washington tax laws in 2026. Here are the 2026 rates based on Washington Department of Revenue guidance:

Classification	2026 Rate
Retailing	0.471%
Wholesaling	0.484%
Government Contracting	0.484%
Public Road Construction	0.484%
Service & Other (prior-year WA income under $1M)	1.50%
Service & Other ($1M–$4,999,999.99)	1.75%
Service & Other ($5M or more)	2.10%
Construction businesses often report income under multiple classifications on the same return. For example, a contractor might have retailing income from homeowner projects, wholesaling income from materials sold to other contractors, and government contracting income from federal projects. Proper classification is critical.

Gross receipts vs. profit: why B&O tax can feel costly

B&O tax applies to gross income, not profit. It is a business tax measured by the gross proceeds or total revenue from in-state business activities, including the income the business earned before expenses are deducted. For example, a Pasco contractor billing $500,000 for cabinetry may spend $200,000 on materials and $150,000 on subcontractors, but the B&O tax is calculated on the full $500,000. At the retailing rate of 0.471%, the tax owed is $2,355.

Unlike retail sales tax, which is tax based on the destination where the customer receives the product or service, businesses must pay taxes under B&O separately while also handling sales tax, and other taxes may apply depending on the business. Few deductions apply beyond specific statutory adjustments like bad debts or returns. This means low-margin industries such as construction and retail must carefully plan pricing and cash flow. Working with bookkeeping services and tax planning experts like Insight Business & Accounting Solutions can help integrate B&O tax into bids and financial management.

Service & Other examples for 2026

The Service & Other classification includes many traditional professional and consulting services that do not have a specific classification elsewhere, and the B&O tax applies to the full amount a business earns before expenses. Examples include legal, accounting, financial consulting, and other professional services that remain outside the expanded retail sales tax categories introduced in October 2025.

Services like security services, investigation services, and custom software development are now generally taxable under the Retailing classification due to the 2025 retail sales tax expansion and should not be listed under Service & Other.

Key B&O classifications and 2026 Washington B&O tax rates

Washington's B&O tax is a set of occupation taxes based on business activities, not business entity type. One business may report gross receipts in multiple classifications on the Combined Excise Tax Return.

The Service & Other rates are tiered by prior-year Washington taxable income, not federal taxable income. For 2026, the applicable Service & Other rate is determined by the business’s 2025 Washington taxable income under that classification. That rate generally applies for the entire 2026 calendar year.

Common classifications:

• Retailing: Sales of tangible personal property to final consumers, plus services now classified as retail sales, including security and investigation services, certain IT services, advertising services, custom website development, and custom software development.
• Wholesaling: Sales to retailers or contractors with valid reseller permits.
• Service & Other: Traditional professional and consulting services not classified elsewhere.
• Government Contracting and Public Road Construction: Contractors working on qualifying public infrastructure projects.

Some businesses may also qualify for limited tax exemptions, and any resulting credit amount should be tracked carefully in the return workpapers.

Standard B&O rates will rise to 0.5% for some classifications effective January 1, 2027.

Multiple activities and the Multiple Activities Tax Credit

The Multiple Activities Tax Credit helps prevent B&O tax from being paid twice on the same amount when more than one taxable activity applies. Businesses still report each applicable activity under the proper classification and claim the credit when eligible. Businesses often report income under multiple B&O classifications. For example, construction companies may sell materials at retail, perform installation work, and provide design consulting, each taxed differently, so they should also review available tax exemptions and credits by classification when determining the final credit amount or tax due.

Retail sales tax vs. B&O tax: 2025–2026 changes

Effective October 1, 2025, Washington expanded retail sales tax to many services previously untaxed, including IT support, advertising, custom software, and some digital automated services. Businesses making taxable retail sales must calculate tax based on where the customer receives the product or service and:

• Collect sales tax from customers at the combined state and local rate.
• Report sales under the Retailing B&O classification.
• Remit both B&O and retail sales tax on the Combined Excise Tax Return via MyDOR, and remote sellers that meet Washington’s threshold must register and remit sales tax.

Contractors working on government projects may report under Public Road Construction or Government Contracting classifications where sales tax is not collected from the government customer but must pay sales and use tax on incorporated materials.

The state retail sales tax rate is 6.5%, plus local sales tax that varies by location. Businesses should use Washington DOR’s current tax-rate lookup for the applicable combined rate.

Washington Small Business B&O Tax Credit in 2026

Small businesses may qualify for a non-refundable B&O tax credit that reduces or eliminates their tax liability. Often called the small business tax credit, it is calculated based on total B&O tax due after other credits across all classifications for the filing period and phases out as gross receipts increase.

There are two credit tables:

• Taxpayers with at least 50% of taxable income in the higher-rate classifications (Service & Other tiers) may receive a maximum credit of $160 per month multiplied by the number of months in the reporting period.
• Other taxpayers may receive a maximum credit of $55 per month multiplied by the number of months in the reporting period.

MyDOR calculates the credit automatically for electronic filers, and businesses still must remit sales tax and report Retailing B&O on the Combined Excise Tax Return.

Special focus: B&O tax for contractors and construction trades

Construction tax rules are complex, and for contractors the small business tax credit under Washington's B&O system does not replace careful classification, especially as you grow, hire employees, and take on added payroll obligations such as unemployment insurance. Contractors must classify income carefully:

• Retailing B&O plus retail sales tax applies when improving real property for homeowners and private businesses.
• Wholesaling B&O applies when selling materials to businesses with valid reseller permits.
• Government Contracting B&O applies to qualifying federal projects and certain housing authorities.
• Public Road Construction classification applies to projects improving public roads.

The Capital Gains B&O Tax Credit is repealed after December 31, 2025, so it is not a 2026 planning option.

Contractors must separately handle retail sales tax obligations. Job-level construction accounting and job costing are essential to separate materials, labor, wholesale, and retail sales and document government contracts.

Insight Business & Accounting Solutions offers specialized construction accounting and business advisory services for contractors in the Tri-Cities.

Reseller permits, wholesale vs. retail sales, and documentation

A Washington reseller permit allows buyers to purchase goods for resale without paying sales tax at purchase. Sellers accepting valid reseller permits classify sales as wholesaling B&O and do not collect retail sales tax.

Key points:

• Sellers must obtain and keep valid reseller permits on file before treating sales as wholesale.
• Permits expire (usually every 2–4 years) and must be current at the sale date.
• Sellers must verify and retain permits for at least five years.

Common errors include accepting expired or invalid permits or assuming buyers are businesses without documentation. Missing or invalid permits can lead to reclassification and penalties.

Registration and filing requirements in Washington

Businesses must register with Washington's Department of Revenue if they:

• Have $12,000 or more in annual gross income.
• Collect retail sales tax.
• Require endorsements.
• Have employees.
• Have nexus in Washington.

DOR assigns filing frequencies based on estimated annual tax liability:

• Annual filers owe $1,050 or less.
• Quarterly filers owe between $1,051 and $4,800.
• Monthly filers owe $4,801 or more.

Businesses must file returns even with zero activity unless placed on active non-reporting status by DOR. Monthly returns are generally due on the 25th of the following month, quarterly returns are due at the end of the month following the quarter, and the 2026 annual Combined Excise Tax Return is due April 15, 2027, subject to weekend and holiday adjustments.

Common B&O bookkeeping and reporting mistakes

Common audit issues include:

• Misclassifying income, such as lumping all revenue into Service & Other.
• Failing to collect retail sales tax on taxable sales.
• Double-reporting revenue without claiming the Multiple Activities Tax Credit.
• Treating sales as wholesale without valid reseller permits.
• Ignoring local B&O or occupation taxes in cities like Seattle, Tacoma, and Bellevue.
• Poor separation of Washington versus out-of-state revenue.

Recordkeeping problems like missing invoices or incomplete bank reconciliations worsen these issues. Accurate bookkeeping, job costing, and integrating QuickBooks Online with professional consulting improve compliance, and understanding Washington tax laws also supports proper documentation and audit readiness.

Other Washington small business taxes (brief overview)

Besides B&O tax, businesses should be aware of:

• Retail sales and use tax (state rate 6.5% plus varying local rates).
• Local occupation taxes in cities and other taxes that vary by jurisdiction.
• Property taxes on business personal property, including personal property tax on business assets and supplies.
• Public utility tax for energy and communication providers, including certain rules involving natural gas.
• Other industry-specific excise taxes, such as the hazardous substance tax in some fuel-related situations.

Integrated bookkeeping and tax planning help manage these taxes alongside B&O, and understanding Washington tax laws while keeping documentation audit-ready helps reduce reporting mistakes.

Tax planning strategies for Washington B&O in 2026

Effective strategies include:

• Accurately classifying revenue to avoid overstating income in higher-rate categories.
• Monitoring prior-year Washington taxable income to anticipate applicable Service & Other rates.
• Evaluating whether services qualify as retail sales versus Service & Other.
• Utilizing the Small Business B&O Tax Credit.
• Incorporating tax costs into bids and contracts.

Local rules vary too; for example, Seattle raised its B&O tax exemption threshold to $2 million.

Insight Business & Accounting Solutions offers tax planning and business advisory https://insightaccountingsolutions.com/business-advisory/ to model tax liabilities, forecast cash flow, and coordinate Washington B&O with federal and local taxes.

How Insight Business & Accounting Solutions supports Washington businesses with B&O tax

Insight Business & Accounting Solutions is a CPA firm based in Richland serving the Tri-Cities and Washington State. Services include:

• Monthly and catch-up bookkeeping organized by B&O classification.
• Construction accounting and job costing.
• Sales tax compliance and nexus reviews.
• Tax preparation and planning focused on Washington small business taxes.
• QuickBooks Online setup and consulting.
• CFO and business advisory services for forecasting and pricing.

Schedule a call to get bookkeeping and tax advice aligned with Washington B&O and retail sales tax requirements.

FAQ: common 2026 Washington B&O questions from small businesses and contractors

Who has to pay Washington B&O tax in 2026? Most businesses operating in Washington are subject to B&O tax based on their activities. Washington tax registration is generally required when annual gross income reaches $12,000 or more, or sooner if the business collects retail sales tax or meets another registration requirement. Businesses with annual B&O gross income of less than $125,000 may qualify for active non-reporting status if they meet Washington Department of Revenue requirements, including not being required to collect retail sales tax.

Do LLCs and S corporations still pay B&O tax? Yes. B&O tax applies to gross receipts regardless of entity type.

How does the Small Business B&O Tax Credit work? It reduces or eliminates B&O tax liability for very small businesses based on total tax owed after other credits. Maximum credits are $160 or $55 per month depending on classification, multiplied by months in the filing period. MyDOR calculates it automatically.

What is the difference between retail sales tax and B&O tax? Retail sales tax is collected from customers on taxable sales and remitted to the state. B&O tax is paid by the business on gross income. Both may apply to the same transaction.

How do contractors handle B&O tax? Contractors may report under multiple classifications depending on the job: retailing for consumer projects, wholesaling for sales to contractors with reseller permits, government contracting for qualifying federal projects, and public road construction for road projects.

What is a reseller permit and why is it important? A reseller permit allows buyers to purchase goods for resale without paying sales tax. Sellers must verify and keep valid permits to classify sales as wholesale and avoid collecting retail sales tax.

When and how do I file B&O tax returns? File the Combined Excise Tax Return through MyDOR monthly, quarterly, or annually based on assigned filing frequency. Returns are required even with zero activity unless on active non-reporting status. Monthly returns are generally due on the 25th of the following month, quarterly returns are due at the end of the month following the quarter, and the 2026 annual Combined Excise Tax Return is due April 15, 2027, subject to weekend and holiday adjustments.

Can I get tax advice for managing B&O tax? Yes. Insight Business & Accounting Solutions provides tax planning and compliance support for Washington small businesses and contractors, including help with B&O classifications, retail sales tax, MyDOR reporting, and related bookkeeping.

Disclaimer: This article is provided for general informational and educational purposes only and is not intended to constitute legal, tax, accounting, or financial advice. The information reflects rules and guidance available as of 2026 and may change. Your specific obligations depend on your business activities, tax classifications, location, and circumstances. Reading this article does not create a CPA-client, attorney-client, or other professional relationship with Insight Business & Accounting Solutions. Consult a qualified professional regarding your specific situation.