Our Services

Shaping your financial future

From audit and assurance to tax planning and client accounting services, Tonneson + Co offers a comprehensive suite of solutions designed to support your business growth. Whatever your goals, whatever stage of business you’re in, we provide high-quality, high-touch services and strategic insights that drive your company forward. We’re more than a service provider. We’re your strategic partner, committed to your success. Discover what it’s like to work with an accounting firm that’s about more than just numbers, we're about you. Learn about our services below.

Audit and Assurance Services

Audit and Assurance Services

Prepping for a sale, acquiring new investment, complying with federal regulations, or going public? Whatever your plans, Tonneson + Co can support you with a wide range of assurance and financial reporting services.

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Client Accounting and Advisory Services

Client Accounting and Advisory Services

Whether you need an extra hand during peak times or a comprehensive, ongoing accounting solution, our Client Accounting and Advisory Services team seamlessly integrates with your operations, providing reliable, timely, and professional services tailored to your needs.

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Dispute Resolution

Dispute Resolution

Disputes can be stressful. When they arise, you need someone who’s got your back. Our Dispute Resolution Services providers are the ally you need, supporting you with clarity, expertise, and strength.

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High Net-Worth, Individual & Family Office

High Net-Worth, Individual & Family Office

If you need an individualized plan to protect your wealth, our High Net-Worth, Individual and Family Office advisors can craft a strategy tailored that aligns with your values and secures your legacy.

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International Tax

International Tax

In a world that’s getting ever-smaller, international tax expertise is increasingly important. Our International Tax Services experts provide customized guidance to global corporations and globe-trotting individuals alike.

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Matrimonial Tax Advisory

Matrimonial Tax Advisory 

The decisions you make during a divorce can have an impact for years to come. Our Matrimonial Tax Advisors are committed to safeguarding your financial well-being and supporting you with sensitivity, professionalism, and confidentiality.

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Mergers & Acquisitions

Mergers & Acquisitions

Mergers and acquisitions can open new horizons of growth for your business. From research and planning to negotiations and closing, Tonneson + Co supports you with specialized expertise and attention to detail every step of the way.

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Succession Planning

Succession Planning

Don’t leave the future to chance. Support your business with a robust succession plan. Our team can help you design a tax-efficient leadership transition that ensures the continuity of your business and honors the legacy of your leadership.

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Tax Planning & Consulting

Tax Planning & Consulting

It doesn’t matter if you’re a small start-up or a large corporation: your tax strategy should be an integral part of your business plan. Our tax team is here to ensure that your tax strategy is aligned with your goals, now and in the future.

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Trusts and Estates

Trusts and Estates

Make sure your wealth is preserved, transferred, and used in a way that aligns with your values and wishes. Our Trust + Estates Services support families and individuals with plans that offer peace of mind and financial security for generations to come.

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Five Tonneson employees surround a conference table, one employee speaks as the other four face towards him and listen.

Pleasure to work with

We have been doing business with Tonneson for over seven years.  Their team is easy to work with and very punctual at meeting deadlines. They are very knowledgeable and informative. On my behalf, I work closely with Joe Lanzi, Rick Mastrocola, and Marie Doucette. They are a pleasure to work with. Our Controller interacts with several members of the audit and tax teams and is very pleased with the services they provide.
—Charlie Masiello | Director, Crystal Motor Express

Valuable business partner

We’ve been working with the team at Tonneson + Co for over 35 years. Their work is timely and accurate, and they are a pleasure to work with. Their team stays current on tax and estate laws, always putting client concerns first. Tonneson is a valuable business partner, playing a key role in our success.

—Michael Tamasi | President & CEO, Accurounds

Financial experts

We have been a client of Tonneson since 1988. We are a small family Logistics company that requires specific financial needs. We have always relied on Tonneson to provide the financial expertise necessary to secure the financing for working capital and equipment purchases. We have gone through several audits and because of the detailed auditing process that Tonneson provides, our experience has been painless. They have been responsive to all our requests and needs. Our business continues to grow and knowing we have Tonneson as our financial partner makes the journey a little easier.

—Michael O'Brien | CEO, Eagle Air Freight, Inc.

Sound financial advice

We have been a client of Tonneson for four decades. We have always received sound financial advice and excellent accounting services over the years. We consider Tonneson to be one of our highly trusted partners.

—Steven Tamasi | President, Boston Centerless

Valued and strategic partner

I consider Tonneson a valued and strategic partner of Signet.

—Bradford Caron | President, Signet

Are you ready to optimize your financial performance? You're just a click away from experiencing top-tier advisory and financial services.