Washington State tax intelligence

Washington tax intelligence, brought into focus.

Research Washington tax law, Department of Revenue guidance, legislative developments, notices, and exemptions — every answer cited to the primary sources.

Regularly updated
Primary-source cited
Free to use

sources indexed: 6,100+
DOR updates tracked: 38
legislative issues tracked: 243
current hot topics: 2

01 · High-interest now

The Current Brief

The Washington tax issues moving right now, and what each one means in practice.

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Washington Retail Services Sales Tax

Track ESSB 5814, ESSB 6113, sourcing, MPU, DOR interim guidance, and the scheduled Jan. 1, 2029 repeal for most newly taxable services (not advertising), which depends on ESSB 6346's income tax surviving court review.

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Washington Millionaires Tax

Follow the 9.90% income-tax program, 2028 start date, 2029 return/payment timeline, litigation risk, and retail-services tax relief connection.

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The standard

Every answer returns to the primary source.

Research here is built on Washington's own published law and guidance, and every answer carries the citation back to it — so you can check the reasoning rather than take it on trust.

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02 · Monitored for changes

Updates

New articles and briefs, reviewed DOR guidance changes, and tax legislation, newest first.

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Oct 17BriefActive / changingWashington Retail Services Sales TaxTrack ESSB 5814, ESSB 6113, sourcing, MPU, DOR interim guidance, and the scheduled Jan. 1, 2029 repeal for most newly taxable services (not advertising), which depends on ESSB 6346's income tax surviving court review.Oct 17ArticleWashington B&O apportionment and the annual reconciliation: a plain-English guideIf a business earns income in an "apportionable" B&O classification (Service and Other Activities, royalties, and a short list of others) and is also taxable in another state or country, Washington law requires it to pay B&O tax on only the Washington share of that income.Oct 14Article2026 Washington excise tax return due dates (monthly, quarterly, annual)Washington monthly excise returns are due the 25th of the following month, quarterly returns at the end of the month after the quarter, and annual returns on April 15 of the next year.Oct 14ArticleWhat changed Oct. 1, 2025 under ESSB 5814: services that now owe Washington sales taxStarting Oct. 1, 2025, ESSB 5814 (ch. 422, Laws of 2025) made several services retail sales in Washington: advertising services, information technology services, custom website development, live presentations, investigation and security services (including armored car), temporary staffing, and custom software and customization of prewritten software.Oct 12BriefImplementation watchWashington Millionaires TaxFollow the 9.90% income-tax program, 2028 start date, 2029 return/payment timeline, litigation risk, and retail-services tax relief connection.Aug 3DOR guidanceSpecial noticeNew DOR Special Notice: Prepayment of Capital Gains TaxThe Washington Department of Revenue has published a new special notice addressing prepayment of the capital gains tax. Here's what taxpayers and advisors should know before relying on it.

03 · Research tools

Explore the research tools

Browse short public previews of the tools on this site. Questionnaires, uploads, calculations, saved work, and deliverables stay in the signed-in workspace when a tool has a working version.

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Tax Rate & Location Code Finder

Find current Washington DOR sales/use tax rates and location codes by address, then save the lookup with your work.

Tax Refund Engine

Upload purchase data and identify potential Washington sales and use tax overpayments for review.

Work Papers

Turn an auditor's workbook into organized findings, exceptions, rate checks, and supporting work papers.

VDA

Organize eligibility, estimated exposure, evidence, review, and a complete voluntary-disclosure package.

Ruling Requests

Develop the transaction facts, questions presented, cited analysis, review record, and finished request package.

Annual Reconciliation

Compare reported figures with actual revenue by state or country, calculate the true-up, and prepare the memo, workbook, and filing packet.

Nexus Monitor

Screen sales-tax nexus across all 50 states and DC, preserve dated state authority, and open a deeper Washington review when needed.

DOR Notices

Keep Department letters private with their deadlines, risk, required actions, requested documents, and supporting excerpts.

Legislative Watchlist

Choose tax topics and industries, rank bills by relevance, and pin the Washington legislation you need to follow.

Taxability Matrix

Keep product and service taxability decisions, authority, jurisdictions, and review status in one maintained record.

04 · Where people get stuck

Common Issues

Practical starting points for the Washington tax problems taxpayers actually need to sort out.

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Received a DOR notice

Prepare for DOR notices, IDR scope, sampling issues, and proposed assessments.

Looking for a refund opportunity

Identify overpayment patterns, refund windows, and documentation gaps before filing.

Need help understanding nexus

Review physical presence, economic thresholds, and Washington-sourced receipts.

Need tax classification guidance

Sort revenue into the right B&O, retailing, service, or specialty classification.

Sales/use & excise compliance

Research sourcing, exemption support, use tax, notices, and filing obligations.

Considering voluntary disclosure

Evaluate VDA eligibility, lookback exposure, penalty relief, and registration steps.

05 · Help and support

Free to use, with optional donations

The research tools stay open to everyone. For a specific situation, ask one free question and a person will reply by email.

Need individualized help?

The research tools handle the groundwork, but audits, appeals, rulings, and disputed assessments need a professional who can look at your specific facts. Ask for a free initial answer on the contact page.

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