Independently owned. Employee driven. Client focused.®
For over 45 years, Tonneson + Co has been helping clients like you thrive by offering expert accounting, tax, and advisory services. We pride ourselves in offering best-in-class service, backed by experience and a desire to see you succeed. Our team of experts can offer personalized service and meaningful relationships that larger firms can’t. That means we can provide hands-on guidance tailored specifically to your needs.
Whether you’re an individual, a privately-held business, or a nonprofit, our team is here to support you with trustworthy advice, timely communication, and up-to-the-minute industry knowledge.
Providing accounting, tax, and advisory services you can trust for over 45 years
Good relationships start with good values. Tonneson + Co supports our clients, our people, and our community by fostering a culture of inclusion, responsibility, and leadership.
Diversity, Equity & Inclusion
Broader perspectives mean better decisions. We strive to create a safe environment for our staff while expanding that message to our professional networks, advisors, and client base. Our internal DEI Committee is dedicated to empowering staff and creating a welcoming environment for all.
Work + Life Balance
Everyone deserves
fulfillment—in and outside of work. Remote-work opportunities and flexible hours help attract top-level talent and allow us to engage a more diverse team.
Professional Development
Our people are our greatest asset. By providing a mentorship program, ongoing training, and an open-door policy, we create a clear path to career advancement and give our employees the tools they need to thrive. This keeps our retention rates high and supports long-lasting client relationships.
Women’s Leadership
We believe in the diversity of perspective and experience, so it’s no surprise that 50% of our firm’s leadership, managing directors, and higher, are female. Tonneson + Co provides the flexibility, support, and opportunity that allow women to advance their careers.
Social Responsibility
We believe in making an impact, so we’re passionate about giving back to our communities. We support a number of charitable organizations and empower our people to serve meaningful local causes, building relationships and connections in the process.
Education & Training
The tax and business landscape is complex. Offering top-notch service means keeping up with industry updates and trends while developing new skills that enhance performance. A robust new-hire onboarding and continuous staff training result in outstanding service for our clients.
News & Insights
Discover thought-leadership from our team of experts
Understanding the Final Estate Tax Basis Consistency Rules: What You Need to Know
Massachusetts DOR Announces New Tax Amnesty Program for 2025
5 Tax Optimization Strategies for Tech Companies
SALT Cap Rule and Its Impact: What You Need to Know
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