Boston CPA Firm for S-Corps & Small Businesses

Looking for a CPA in Boston? SDO CPA provides virtual tax preparation, bookkeeping, payroll, and fractional CFO services to Boston 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 Boston 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 Boston’s Biotechnology, Financial Services, Higher Education & Healthcare economy. Whether you’re managing Boston’s high cost of living and the millionaire’s surtax mean business owners face effective combined federal-state rates exceeding 46% without proper planning or capitalizing on The Seaport Innovation District and Kendall Square create one of the world’s densest startup ecosystems, with $30 billion in annual venture funding across Greater Boston, SDO CPA provides the virtual accounting support your business needs.

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

Key Takeaways: Boston CPA Services

  • Virtual CPA services — Full tax, bookkeeping, and advisory support without geographic limitations
  • Massachusetts tax expertise — MA flat 5% income tax plus new 4% surtax on income over $1M (eff. 2023). Pass-through entity excise (PTEE) at 5% provides SALT workaround. planning and multi-state compliance
  • Industry focus — Specialized experience with Biotechnology, Financial Services, Higher Education & 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 Boston, MA

Boston’s economy generates over $480 billion in metro GDP, driven by a biotech corridor that stretches from the Seaport District through the Longwood Medical Area and into Kendall Square in Cambridge. The city hosts Mass General Brigham, Beth Israel Deaconess, and Boston Children’s Hospital, forming a healthcare cluster that employs 150,000 workers across the metro. The Financial District along State Street and Federal Street houses Fidelity Investments, State Street Corporation, and Wellington Management, managing trillions in global assets. The Seaport Innovation District has attracted Amazon, Reebok, and hundreds of startups to a waterfront neighborhood that barely existed 15 years ago. Boston’s venture capital ecosystem deployed $30 billion in 2024, second only to the San Francisco Bay Area nationally. The Back Bay, Newbury Street, and South End neighborhoods support thousands of independent retailers, restaurants, and professional services firms. SDO CPA serves Boston business owners with millionaire’s surtax planning, PTEE elections for pass-through entities, R&D tax credits for biotech and tech startups, and S-Corp structuring for physicians and financial professionals.

Massachusetts Tax Planning Tip

Massachusetts’ new millionaire’s surtax adds 4% on income over $1M, making the effective rate 9%. The PTEE election allows pass-through entities to pay at the entity level, creating a federal deduction. Business owners near the $1M threshold should carefully time income recognition and consider entity-level strategies.

Boston is home to 52,000+ small businesses and a population of 675,647. From Biotechnology, Financial Services, Higher Education & Healthcare to professional services, Boston business owners need CPAs who understand Boston’s high cost of living and the millionaire’s surtax mean business owners face effective combined federal-state rates exceeding 46% without proper planning and can provide year-round tax planning — not just compliance.

CPA Services for Boston Businesses

Common Challenges for Boston Business Owners

Challenge

Boston businesses often face Boston’s high cost of living and the millionaire’s surtax mean business owners face effective combined federal-state rates exceeding 46% without proper planning, 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 Boston’s business environment, helping you handle Boston’s high cost of living and the millionaire’s surtax mean business owners face effective combined federal-state rates exceeding 46% without proper planning with confidence.

Challenge

Many Boston 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 Boston 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.

“Our Boston medical practice crossed the $1M threshold last year. SDO CPA implemented income timing strategies and the PTEE election that saved our partnership $73,500 in combined taxes.”
— Christine A., Medical practice partner in Boston

How to Get Started With SDO CPA

1

Schedule Your Free Consultation

Book a call to discuss your Boston 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 Boston Business Owners Choose SDO CPA

Massachusetts Tax Expertise

We understand MA flat 5% income tax plus new 4% surtax on income over $1M (eff. 2023). Pass-through entity excise (PTEE) at 5% provides SALT workaround. and help Boston 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 Boston 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 Boston?
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 Boston business?
Yes. CPAs can prepare tax returns and provide accounting services for clients in any state. SDO CPA serves Boston 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 Biotechnology businesses?
Yes. Boston’s Biotechnology sector has unique accounting needs including industry-specific deductions, revenue recognition, and compliance requirements that we address with tailored solutions.
What is the difference between a bookkeeper and a CPA?
A bookkeeper records transactions and maintains financial records. A CPA is a state-licensed professional who can prepare and sign tax returns, provide tax planning advice, represent you before the IRS, and offer strategic financial guidance that bookkeepers cannot.
Do you offer fractional CFO services for Boston businesses?
Yes. Our fractional CFO services provide cash flow forecasting, budgeting, financial modeling, and strategic planning for Boston businesses generating $500K+ in revenue that need financial leadership without a full-time hire.
Should my Boston 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 Boston business during your free consultation. Learn about our bookkeeping services.

Resources for Boston Business Owners

Also Serving Greater Boston

SDO CPA provides virtual CPA services to businesses throughout Greater Boston and Massachusetts.

Ready to Work With a CPA Who Understands Boston Businesses?

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

Schedule a Call
Licensing Disclaimer: SDO CPA LLC is a Texas-registered CPA firm providing tax preparation, bookkeeping, and advisory services to clients nationwide under CPA practice mobility provisions. SDO CPA does not hold a CPA license in Massachusetts. Services requiring CPA licensure are performed by Texas-licensed CPAs. We do not provide attest services (audits, reviews, or compilations) for Massachusetts entities. Per Texas State Board of Public Accountancy regulations (22 TAC §501.82).