Leading the Way: Why Our Clients Say We Are Among the Top Accounting, Tax, Advisory Firms

Independently owned. Employee driven. Client focused.®

We’ve heard all the stereotypes — that accountants are introverted, stodgy, and only interested in crunching numbers. But in an ever-changing economic landscape, you don’t need a by-the-books number cruncher. You need someone with the creativity, insight, and knowledge to help you achieve your goals. That’s Tonneson + Co.

Sure, we love numbers, we’re also friendly and approachable. We believe that personal connections are the key to great service. And we’re passionate about helping you grow, flourish, and prepare for the future. Our people drive our firm’s culture, exceptionally talented individuals with an unmatched commitment to our client’s success. The Tonneson + Co team is known for our quality of service, responsiveness, communication, and fresh ideas. Our people are our greatest asset, they can be yours, too.

Our Mission + Values

Since 1975, our core values have guided our actions, and our fundamental beliefs have defined our decision-making. We are invested in our people—and our people are how we have become an industry leader.

At Tonneson + Co, our company culture is defined by:
  • Diversity, Equity + Inclusion
  • Work + Life Balance
  • Professional Development
  • Women's Leadership
  • Social Responsibility
  • Education + Training

Our culture means living our values, learning new things, and having fun. This includes building relationships, establishing personal connections with our clients and partners, and nurturing our commitment to ongoing excellence.

We are proud to be named to Accounting Today’s 2023 list of Best Accounting Firms to Work For. Our firm was also named to this list in 2022, 2021, 2020, 2019, 2018, and 2016.

In 2023, we were recognized as an “Inclusive Workplace” by Best Companies Group, a workplace culture and employee engagement expert, and COLOR magazine, a leader in corporate inclusivity. We were also named to this list in 2022. 

Tonneson + Co was named to the list of Largest Accounting Firms in Massachusetts by the Boston Business Journal. We are ranked as the 22nd largest firm in the state in 2024 and 2023. This data is based on the number of employees, CPAs, and partners in Massachusetts.

accounting today logo for the 2021 best firms for womenWe were proud to be named the #1 firm for Women in the U.S. by Accounting Today. This recognition is based on the direct feedback from our female staff to a comprehensive employee survey.

Greater Boston Chamber of Commerce Small Business of the Year award 2021
We were named Small Business of the Year 2021 in the Innovation and Growth category, by the Greater Boston Chamber of Commerce. This award recognizes businesses that develop or utilize technology and practices that innovate and accelerate their growth. 

We've received an impressive 4.6 rating on Glassdoor, which reflects our commitment to creating a positive and fulfilling work environment for all of our employees.


We've received an impressive 4.6 rating on Glassdoor, which reflects our commitment to creating a positive and fulfilling work environment for all of our employees.

Our People Supporting Your People. Let’s Do Great Things Together.

Four employees in a group together at the office

Your Financial Partner

We Bring "Why" to Our Client’s

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