Washington CPA Firm for S-Corps & Small Businesses

Looking for a CPA in Washington? SDO CPA provides virtual tax preparation, bookkeeping, payroll, and fractional CFO services to Washington businesses specializing in S-Corps and partnerships. We provide upfront estimates — if scope changes, we discuss it first. Schedule a free consultation.
Serena Do, CPA — Managing Partner of SDO CPA

Serena Do, CPA

Managing Partner | Duncanville, TX (Serving Washington Virtually)

18+ Years Experience | AICPA Member

Licensed CPA — Texas State Board of Public Accountancy

With 18+ years of experience helping business owners across the country, I bring specialized expertise to Washington’s Technology, Aerospace, Healthcare economy. Whether you’re managing B&O tax classification and multi-state sales tax obligations or capitalizing on Washington’s zero state income tax advantage for business owners and employees, SDO CPA provides the virtual accounting support your business needs.

We offer cloud-based tax preparation, bookkeeping, payroll, and fractional CFO services designed for Washington business owners who want proactive guidance — not just annual tax filing.

Key Takeaways: Washington CPA Services

  • Virtual CPA services — Full tax, bookkeeping, and advisory support without geographic limitations
  • Washington tax expertise — Washington has no state income tax, but B&O tax on gross receipts applies to most businesses planning and multi-state compliance
  • Industry focus — Specialized experience with Technology, Aerospace, Healthcare
  • Transparent pricing — Upfront estimates starting at $300/month; if scope changes, we discuss it first
  • Responsive support — Direct CPA access, same-day responses

Accounting & Tax Services in Washington

Washington’s tech sector accounts for 22% of the state economy, the highest percentage in the nation. The Greater Seattle-Bellevue metro generates over $560 billion in gross regional product, powered by Amazon, Microsoft, Boeing, and hundreds of startups along the I-405 corridor and South Lake Union. With no personal or corporate income tax, Washington attracts business owners and high-earning tech employees from across the country.

Washington’s Business & Occupation (B&O) tax on gross receipts replaces income tax as the primary state business obligation. Different classifications carry different rates, and many businesses overpay because they default to the wrong category. S-Corp owners selling into states that do impose income tax face multi-state nexus considerations, while the state’s sales tax on goods and many services adds another layer of compliance complexity.

SDO CPA serves Washington businesses statewide, from Seattle tech startups to Spokane healthcare practices and Vancouver cross-border operations. We provide virtual tax preparation, bookkeeping, payroll, and fractional CFO services tailored to Washington’s unique tax structure. Whether you’re an S-Corp owner in Bellevue’s tech corridor or a partnership running logistics through the Port of Tacoma, we handle B&O tax optimization, federal tax planning, and multi-state compliance so you can focus on growing your business.

Washington Tax Planning Tip

Washington has no state income tax, but the B&O (Business & Occupation) tax applies to gross receipts at rates varying by classification: 1.5% for service businesses, 0.471% for manufacturing, and 0.484% for retailing. Many Washington businesses overpay because they file under the wrong classification or miss available credits and deductions. Proper classification review and tax credit identification can reduce your B&O liability significantly.

Washington is home to 620,000+ small businesses and a population of 7,812,880. From Technology, Aerospace, Healthcare to professional services, Washington business owners need CPAs who understand B&O tax classification and multi-state sales tax obligations and can provide year-round tax planning — not just compliance.

CPA Services for Washington Businesses

Common Challenges for Washington Business Owners

Challenge

Washington businesses often face B&O tax classification and multi-state sales tax obligations, making tax planning and cash flow management more complex than standard approaches allow.

Our Approach

We provide proactive tax planning and fractional CFO services tailored to Washington’s business environment, helping you handle B&O tax classification and multi-state sales tax obligations with confidence.

Challenge

Many Washington business owners struggle to get timely responses from their CPA, especially during busy seasons when questions are most urgent.

Our Approach

SDO CPA provides direct access to your CPA team with same-day response times. No call centers, no waiting weeks for answers.

Challenge

Tax preparation alone doesn’t help Washington business owners understand their financial position or make informed decisions throughout the year.

Our Approach

We deliver monthly financial reports with actionable insights, helping you understand cash flow, profitability, and tax liability before year-end.

“As a Seattle SaaS startup, we needed a CPA who understood our metrics, equity structure, and investor expectations. SDO CPA helped us prepare clean financials for our Series A and now manages our ongoing accounting seamlessly.”
— Rachel T., SaaS startup founder in Washington

How to Get Started With SDO CPA

1

Schedule Your Free Consultation

Book a call to discuss your Washington business, current financial setup, and goals.

2

Get Your Custom Proposal

Receive a clear proposal with upfront estimates — if scope changes, we discuss it first.

3

Seamless Onboarding

We connect to your QuickBooks or Xero and organize your books within 30 days.

4

Ongoing Partnership

Monthly reports, proactive tax planning, and year-round CPA access.

Why Washington Business Owners Choose SDO CPA

Washington Tax Expertise

We understand Washington has no state income tax, but B&O tax on gross receipts applies to most businesses and help Washington businesses maximize tax advantages while managing federal obligations and multi-state complexity.

Transparent Pricing

Clear monthly estimates for standard services. We scope your needs upfront and communicate before any additional work. See our pricing.

Cloud-Based & Virtual

Access your financials anywhere. We work with QuickBooks Online, Xero, Gusto, and Ramp to keep your Washington business running smoothly.

S-Corp & Partnership Specialists

Our clients are pass-through entity owners. We handle reasonable compensation analysis, K-1 preparation, QBI optimization, and entity selection.

Responsive Communication

Get answers when you need them. Our team responds within one business day, and you’ll have direct access to your CPA.

Frequently Asked Questions

How much does a CPA cost for a small business in Washington?
At SDO CPA, bookkeeping starts at $300-$500 per month for a single entity. Full-service packages including bookkeeping, tax planning, and advisory range from $1,000-$2,000 per month with upfront estimates — if scope changes, we discuss it first. View our pricing.
Can a virtual CPA serve my Washington business?
Yes. CPAs can prepare tax returns and provide accounting services for clients in any state. SDO CPA serves Washington businesses through secure cloud-based tools including QuickBooks Online, Gusto, and encrypted document sharing with the same quality as a local firm.
Do you specialize in Technology businesses?
Yes. Washington’s Technology sector has unique accounting needs including equity compensation planning, SaaS revenue recognition, R&D tax credits, and compliance requirements that we address with tailored solutions.
Can you help with Washington B&O tax and sales tax?
Absolutely. Washington’s B&O tax on gross receipts and sales tax requirements can be complex. We help ensure proper classification, optimize timing of payments, and verify you’re not overpaying based on incorrect business activity codes.
Do you offer fractional CFO services for Washington businesses?
Yes. Our fractional CFO services provide cash flow forecasting, budgeting, financial modeling, and strategic planning for Washington businesses generating $500K+ in revenue that need financial leadership without a full-time hire.
Should my Washington business be an S-Corp or LLC?
It depends on your net income. Generally, businesses earning over $60,000 in net profit may save on self-employment taxes by electing S-Corp status. Use our S-Corp tax calculator to estimate savings, then schedule a consultation for personalized analysis.
How quickly does SDO CPA respond to questions?
We respond to all client inquiries within one business day. For urgent tax matters, we prioritize same-day responses. You’ll have direct access to your CPA — no call centers or gatekeepers.
What accounting software do you work with?
We work with QuickBooks Online, Xero, Gusto for payroll, and Ramp for expense management. We’ll recommend the best setup for your Washington business during your free consultation. Learn about our bookkeeping services.

Resources for Washington Business Owners

Serving Washington Businesses Statewide

SDO CPA provides virtual CPA services to businesses throughout Washington.

Ready to Work With a CPA Who Understands Washington Businesses?

Schedule your free consultation today. We’ll analyze your tax situation and provide an upfront estimate with no obligation.

Schedule a Call
Licensing & Service Disclaimer: SDO CPA LLC is a Texas-licensed CPA firm serving clients in Washington under CPA practice mobility provisions. We do not maintain a physical office in Washington — all services are delivered remotely via secure video, phone, and digital collaboration tools. SDO CPA does not hold a CPA license in Washington. Services requiring CPA licensure are performed by Texas-licensed CPAs. We do not provide attest services (audits, reviews, or compilations). Per Texas State Board of Public Accountancy regulations (22 TAC §501.82).