Finding the right accounting firm in Seattle can determine whether your business thrives through tax season or scrambles to catch up on compliance. With Washington’s unique B&O tax structure, no state income tax, and increasingly complex multi-state sales tax obligations for e-commerce and SaaS companies, Seattle businesses face financial challenges that demand specialized expertise.
The Seattle metro area hosts everything from Big Four offices serving Fortune 500 clients to boutique CPAs who understand the specific needs of tech startups burning through runway. Whether you need audit services, strategic tax planning, or help managing multi-state sales tax registrations and filings, the right firm becomes a growth partner—not just a compliance checkbox.
Key takeaways
- Clark Nuber PS stands out as the only single-office firm in Accounting Today’s 2025 Top 100, with more than 70 years of Bellevue-based expertise and a 2025 national rank of No. 90
- Moss Adams LLP leads the West Coast following its merger with Baker Tilly, creating one of the 10 largest firms in the U.S. with deep state and local tax capabilities
- Tech-specialized firms like Huddleston Tax CPAs and Duskin CPA focus specifically on SaaS revenue recognition, startup coaching, and e-commerce bookkeeping
- Big Four presence (Deloitte, EY, KPMG) provides enterprise-grade resources for multinational corporations and companies preparing for IPO
- Regional leaders like RSM offer middle-market expertise with accessible service models
- Sales tax complexity remains underserved—most Seattle accounting firms offer SALT services but lack specialized automation for multi-state compliance
1. Clark Nuber PS
Clark Nuber has earned its reputation as a Seattle-area standout through 70+ years of dedicated service. The firm ranks No. 90 nationally in Accounting Today’s 2025 Top 100 and is notable as the only single-office firm on that list.
Core capabilities:
- Tax planning and preparation for private companies
- State and local tax compliance
- Audit and assurance services
- Business consulting and not-for-profit organization services
What makes Clark Nuber stand out:
With 300+ professionals, Clark Nuber serves clients who need more than a Big Four cookie-cutter approach but want deeper resources than a small local CPA can provide. The firm relocated to City Center Plaza in September 2025, signaling continued investment in the Eastside market. Clients consistently praise the tax team’s diligence in delivering state and federal tax savings.
Contact:
(425) 454-4919
Best for:
Mid-sized businesses seeking regional expertise with national-caliber capabilities, particularly those needing Washington state tax guidance.
2. Deloitte LLP
Deloitte operates from the Third Avenue corridor in downtown Seattle. Deloitte holds the #1 position as the largest accounting firm in the U.S. by revenue at $33 billion according to the 2025 IPA 500. For Seattle enterprises requiring global reach, digital transformation consulting, or IPO preparation, Deloitte’s resources are unmatched.
Core capabilities:
- Enterprise tax services across multiple jurisdictions
- Digital transformation consulting
- Audit and assurance for public companies
- Risk advisory and compliance
What makes Deloitte stand out:
The firm’s technology and automation capabilities make them particularly relevant for Seattle’s tech-heavy business environment. While Deloitte provides tax strategy, growing businesses often work with Deloitte for strategic planning while partnering with managed compliance services for sales tax filing execution.
Contact:
Contact via website
Best for:
Fortune 500 companies, pre-IPO businesses, and enterprises requiring global tax and audit capabilities.
3. Moss Adams and Baker Tilly
Moss Adams and Baker Tilly combined in 2025, creating a much larger national platform while preserving a strong Seattle and West Coast presence. The combined organization serves Seattle businesses from the downtown core, including Baker Tilly’s Seattle office at 999 Third Ave, Suite 2800, and brings together Moss Adams’ regional strength with Baker Tilly’s broader national scale.
Core capabilities:
- State and local tax services
- Tax, audit, and assurance services
- Advisory services for middle-market and growth-stage businesses
- Technology, digital transformation, and risk consulting
- Industry-focused services for sectors including technology, construction, and manufacturing
What makes Moss Adams and Baker Tilly stand out:
This combination gives Seattle clients access to one of the largest advisory and CPA platforms in the country while retaining the Pacific Northwest depth that made Moss Adams a longstanding regional leader. For businesses dealing with Washington tax issues, multi-state expansion, or more sophisticated audit and advisory needs, Moss Adams and Baker Tilly offer substantially more scale and specialization than either firm could provide alone prior to the merger.
Contact:
(206) 302-6500
Best for:
Middle-market companies, technology firms, manufacturers, and businesses seeking national-scale resources with strong Pacific Northwest roots.
4. KPMG LLP
KPMG’s Seattle office brings Big Four capabilities with particular strength in global mobility advisory—critical for Seattle’s tech companies managing international workforces and remote employees across multiple jurisdictions.
Core capabilities:
- Global mobility advisory for international assignments
- Tax compliance for multinational corporations
- Audit services for public companies
- Technology and innovation consulting
What makes KPMG stand out:
The firm’s international presence makes them particularly valuable for Seattle businesses expanding into global markets. For companies with employees creating physical nexus in multiple states through remote work arrangements, KPMG can advise on the tax implications while specialized compliance partners handle the actual state registrations and ongoing filings.
Contact:
Contact via website
Best for:
Multinational corporations, companies with international workforces, and businesses requiring global tax compliance coordination.
5. RSM US LLP
RSM was ranked No. 5 on Accounting Today’s 2025 Top 100 Firms list and is widely known for its focus on middle-market clients. The firm earned #8 in Vault’s Best Accounting Firms to Work For, praised for career development and work-life balance—factors that translate to lower staff turnover and more consistent client relationships.
Core capabilities:
- Tax compliance and planning for growth-stage companies
- Assurance services scaled for mid-sized organizations
- Consulting services
- Industry-specific expertise across sectors
What makes RSM stand out:
RSM’s sweet spot aligns with businesses between $10M and $500M in revenue—large enough to need sophisticated tax planning but not requiring the global infrastructure of a Big Four firm. Their middle-market focus means CPAs who understand the specific challenges of scaling companies, including the e-commerce nexus complexities that emerge during rapid growth.
Contact:
Contact via website
Best for:
Growth-stage companies seeking Big Four-adjacent capabilities at middle-market service levels.
6. Grant Thornton LLP
Grant Thornton ranks among the largest accounting firms in the U.S.; 2025 IPA coverage placed the U.S. firm at roughly $2.37 billion in net revenue, while Grant Thornton International reported $8.5 billion in global revenue for FY2025. The firm’s reputation centers on independent audit services and middle-market business consulting.
Core capabilities:
- Independent audit services for public and private companies
- Tax advisory and compliance
- Business consulting and transaction support
- Multi-location business services
What makes Grant Thornton stand out:
Client reviews consistently describe Grant Thornton as having “top-notch professionals making the entire process very seamless and smooth.” The firm balances national reach with attentive service. For Seattle businesses preparing for acquisition or requiring audit-ready financials, Grant Thornton provides credibility that smaller regional firms can’t match. Companies managing sales tax audits often benefit from having Grant Thornton’s audit expertise combined with specialized sales tax support that can produce the documentation auditors require.
Contact:
Contact via website
Best for:
Companies requiring independent audits, preparing for M&A transactions, or needing credible financial statements for investors.
7. Huddleston Tax CPAs
Huddleston Tax CPAs built their practice specifically around Seattle’s tech ecosystem. Unlike generalist firms that serve tech clients occasionally, Huddleston focuses primarily on SaaS companies, e-commerce businesses, and startups navigating early growth challenges.
Core capabilities:
- SaaS revenue recognition and Rule of 40% measurement
- Startup coaching and financial consulting
- E-commerce bookkeeping with digital-first workflows
- Churn rate analysis and first-year profitability forecasting
What makes Huddleston Tax CPAs stand out:
The firm understands metrics that matter to SaaS founders—MRR, churn, CAC, LTV—and translates them into tax-efficient structures. For startups selling software across state lines, Huddleston can advise on SaaS taxability variations by state while specialized compliance services handle the actual multi-state registrations and filing execution.
Contact:
(425) 483-6600
Best for:
Tech startups, SaaS companies, and e-commerce businesses seeking CPAs who speak their language.
8. Duskin CPA
Duskin CPA positions itself as Seattle’s top-rated bookkeeper, tax strategist, and CPA for tech startups and SaaS companies. The firm offers free tax analysis for tech companies, making initial engagement low-risk for cash-conscious startups.
Core capabilities:
- Multi-state sales tax compliance advisory
- Washington B&O tax compliance
- R&D tax credits optimization
- Stock option planning and equity compensation expertise
- Cash flow forecasting and burn rate management
- Investor-ready financials preparation
What makes Duskin CPA stand out:
Duskin’s proactive approach to tax planning—rather than reactive tax preparation—appeals to founders who want to minimize liability before year-end, not discover surprises after. The firm explicitly targets online sellers dealing with multi-state sales tax complexity, though the execution of those filings across 40+ states often requires the automation that managed sales tax services provide.
Contact:
(425) 345-2299
Best for:
Early-stage startups, bootstrapped founders, and tech companies preparing for fundraising.
9. The Akopyan Group CPAs
The Akopyan Group (formerly Yuriy G Akopyan Group) serves tech companies, closely held businesses, and entrepreneurs across the Eastside. The December 2025 merger with Toyer, Dietrich, CPAs expanded their capabilities and team depth.
Core capabilities:
- Technology company and startup accounting
- Small business accounting solutions
- Tax services for business and personal returns
- Bookkeeping and payroll through Sound Payroll partnership
- Part-time CFO services for growing companies
What makes The Akopyan Group stand out:
The firm’s promise of “accounting expertise and proactive guidance to help Seattle-area businesses maximize their potential” resonates with founders who want a single point of contact for financial operations. Their integrated payroll services eliminate the friction of coordinating multiple vendors—a common pain point for startups scaling their teams.
Contact:
(206) 838-3800
Best for:
Tech startups and closely held businesses seeking integrated accounting, payroll, and CFO services in one relationship.
10. Withum
Withum ranks as a Top 25 firm nationally and brings specialized capabilities that distinguish it from generalist competitors. The Seattle office, led by Partner in Charge Joe Thiermann, relocated in July 2025 to support regional growth.
Core capabilities:
- Cybersecurity services and IT risk assessment
- ERISA practice for employee benefit plans
- Forensic and valuation services
- Outsourced accounting systems (OASyS)
- State and local tax services
What makes Withum stand out:
For Seattle tech companies facing increasing cybersecurity scrutiny from investors and customers, Withum’s combination of accounting expertise and IT security assessment provides unique value. Their forensic capabilities also serve businesses dealing with fraud investigations or litigation support needs.
Contact:
(206) 522-6370
Best for:
Companies requiring cybersecurity assessment alongside accounting, ERISA compliance, or forensic investigation support.
11. Vazquez CPA & Company
Vazquez CPA serves tech startups and established technology companies with a virtual-first model that aligns with how modern businesses operate. Their focus on eliminating financial obstacles for tech businesses translates to practical, accessible guidance.
Core capabilities:
- Hi-tech startup services from incorporation through growth
- Tax planning services
- QuickBooks setup and ongoing support
- Outsourced bookkeeping with cloud workflows
- Cash flow analysis for tech firms
- Mergers and acquisitions support
- Outsourced CFO services
What makes Vazquez CPA stand out:
The firm’s extended hours (until 6:00 PM) accommodate founders who work non-traditional schedules. For companies managing bookkeeping mistakes that create tax complications, Vazquez offers remediation alongside forward-looking strategy.
Contact:
(888) 268-1040
Best for:
Tech companies preferring virtual engagement and flexible scheduling.
Frequently asked questions
What’s the difference between an accountant and a bookkeeper in Seattle?
Bookkeepers handle daily transaction recording, reconciliation, and financial data entry. Accountants—particularly CPAs—provide higher-level services including tax planning, audit preparation, financial statement analysis, and strategic advisory. Many Seattle businesses use bookkeeping services for day-to-day operations while engaging CPAs for quarterly reviews and annual tax work. Firms like The Akopyan Group offer both services integrated, while specialists like Huddleston focus purely on CPA-level work.
How much do Seattle accounting firms charge?
Pricing varies dramatically by firm size and service scope. Most firms require consultations for quotes since pricing depends on business complexity, entity structure, and service needs. Few Seattle firms publish fixed pricing, though several offer free initial consultations.
Can a Seattle accounting firm handle multi-state sales tax for e-commerce?
Most Seattle accounting firms offer state and local tax advisory—11 of the 18 major firms explicitly mention this capability. However, “advisory” differs from “execution.” CPAs typically advise on nexus thresholds and tax strategy but don’t execute the daily compliance work of tracking rate changes across thousands of jurisdictions, filing returns in 40+ states monthly, or responding to state notices within required timeframes. E-commerce businesses often pair their CPA’s strategic guidance with managed compliance services that handle the operational execution.
What questions should I ask when interviewing Seattle accounting firms?
Focus on fit rather than just credentials. Ask: What percentage of your clients are in my industry? Who will actually work on my account—partners or junior staff? How do you handle sales tax compliance for multi-state sellers? What’s your average response time for urgent questions? Can you provide references from similar-sized businesses? How do you bill—hourly, fixed fee, or hybrid? The answers reveal whether the firm understands your specific challenges and can deliver responsive service.
Are there specific considerations for Seattle tech startups?
Yes. Seattle startups face unique challenges including R&D tax credit optimization, stock option planning, SaaS revenue recognition rules, and burn rate management. Washington’s B&O tax adds complexity that CPAs from other states may not understand. Additionally, tech companies often trigger economic nexus thresholds quickly due to digital sales nationwide—requiring proactive nexus monitoring before liabilities accumulate. Firms like Huddleston and Duskin built practices specifically around these challenges.
