Cambridge CPA Firm for S-Corps & Small Businesses

Looking for a CPA in Cambridge? SDO CPA provides virtual tax preparation, bookkeeping, payroll, and fractional CFO services to Cambridge 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 Cambridge 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 Cambridge’s Biotechnology & Pharma, Technology, Higher Education economy. Whether you’re managing Biotech founders face complex equity compensation, stock option exercise timing, and milestone-based income that triggers the millionaire’s surtax unpredictably or capitalizing on Kendall Square houses the world’s densest cluster of biotech firms, with lab space rents exceeding $100/sq ft reflecting insatiable demand for R&D facilities, SDO CPA provides the virtual accounting support your business needs.

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

Key Takeaways: Cambridge 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 & Pharma, Technology, Higher Education
  • 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 Cambridge, MA

Cambridge is the global epicenter of biotechnology and academic research, home to MIT, Harvard, and the Kendall Square innovation district where over 150 biotech companies occupy 14 million square feet of lab and office space. Moderna, Novartis, Pfizer, and Sanofi all maintain major research operations within walking distance of the MIT campus, alongside hundreds of early-stage startups funded by the $30 billion in annual venture capital flowing into Greater Boston. Harvard Square, Central Square, and Inman Square form distinct commercial districts supporting restaurants, bookshops, and professional services that serve the city’s 118,000 residents and 40,000 daily commuters. Google’s 400,000-square-foot Cambridge campus and Microsoft’s New England Research Lab add tech industry depth beyond biotech. The Cambridge Innovation Center (CIC) houses 1,000+ startups across 230,000 square feet of coworking space. SDO CPA works with Cambridge biotech founders on R&D tax credit documentation, stock option exercise planning around the millionaire’s surtax threshold, PTEE elections for pass-through entities, and entity structuring for companies transitioning from pre-revenue to commercial stage.

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.

Cambridge is home to 8,200+ small businesses and a population of 118,403. From Biotechnology & Pharma, Technology, Higher Education to professional services, Cambridge business owners need CPAs who understand Biotech founders face complex equity compensation, stock option exercise timing, and milestone-based income that triggers the millionaire’s surtax unpredictably and can provide year-round tax planning — not just compliance.

CPA Services for Cambridge Businesses

Common Challenges for Cambridge Business Owners

Challenge

Cambridge businesses often face Biotech founders face complex equity compensation, stock option exercise timing, and milestone-based income that triggers the millionaire’s surtax unpredictably, 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 Cambridge’s business environment, helping you handle Biotech founders face complex equity compensation, stock option exercise timing, and milestone-based income that triggers the millionaire’s surtax unpredictably with confidence.

Challenge

Many Cambridge 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 Cambridge 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.

“When our Cambridge biotech hit a licensing milestone, SDO CPA had already structured our income timing to minimize the millionaire’s surtax impact. They saved our founding team $92,100 across three K-1s.”
— Priya S., Biotech company co-founder in Cambridge

How to Get Started With SDO CPA

1

Schedule Your Free Consultation

Book a call to discuss your Cambridge 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 Cambridge 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 Cambridge 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 Cambridge 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 Cambridge?
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 Cambridge business?
Yes. CPAs can prepare tax returns and provide accounting services for clients in any state. SDO CPA serves Cambridge 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 & Pharma businesses?
Yes. Cambridge’s Biotechnology & Pharma 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 Cambridge businesses?
Yes. Our fractional CFO services provide cash flow forecasting, budgeting, financial modeling, and strategic planning for Cambridge businesses generating $500K+ in revenue that need financial leadership without a full-time hire.
Should my Cambridge 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 Cambridge business during your free consultation. Learn about our bookkeeping services.

Resources for Cambridge 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 Cambridge 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).