What Tonneson + Co does

Tonneson + Co is a private, for-profit professional services firm headquartered in Wakefield, Massachusetts, founded in 1975 and operating with an estimated 101-250 employees. The firm delivers an integrated portfolio of audit and assurance, tax, consulting, and wealth management services to a diverse client base spanning aerospace and defense, manufacturing, automotive, consumer products, food and beverage, private equity, technology, healthcare, financial services, government, not-for-profit, and high net worth individuals. Core service lines include financial statement audits, employee benefit plan audits, SEC surprise audits, international audits, and single audits; tax compliance and planning across international, M&A, corporate, personal, state and local, transfer pricing, and tax controversy; consulting in AI, cybersecurity, data and analytics, ERP, finance and accounting advisory, forensic accounting, investment banking, outsourced finance, restructuring, risk management, strategy, supply chain, technology, and transaction advisory; and wealth management encompassing estate planning, family office, financial planning, investment advisory, and trust services.

Name

Tonneson + Co

Legal name

Plante & Moran, PLLC

Website

https://tonneson.com

Company type

Private

Founded year

1924

Operating status

Operating

Headcount range

101–250 employees

Short description

Tonneson + Co is a Massachusetts-based private accounting firm offering integrated audit, tax, consulting, and wealth management services to clients across manufacturing, healthcare, private equity, technology, government, and other verticals.

Ownership category

akta.pro rank

Headquarters

HQ city

Wakefield

HQ country

United States

HQ region

North America

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations, Technology or R&D, Marketing or Sales, Infrastructure

Revenue model

1. Audit and Assurance Services: Financial statement audits, employee benefit plan audits, SEC surprise audits, single audits, and international audit services for various industries
2. Tax Services: International tax, mergers & acquisition tax, national corporate tax, personal tax, state & local tax, tax controversy services, tax credits, incentives & deductions, and transfer pricing
3. Consulting Services: AI consulting, cybersecurity, data and analytics, ERP consulting, finance & accounting advisory, forensic accounting, investment banking, outsourced finance and accounting, restructuring & turnaround, risk management, strategy, supply chain & operations, technology consulting, transaction advisory services, and valuation services
4. Wealth Management: Business transition services, estate planning, family legacy, family office services, financial planning, insurance, investment advisory, personal tax planning, and trust services

Distribution channels2 records

Marketing channels5 records

Core offering

Tonneson + Co is a professional services accounting firm providing audit and assurance, tax, consulting, and wealth management services. Its services span financial statement audits, employee benefit plan audits, international tax, M&A tax, transfer pricing, AI and cybersecurity consulting, investment banking, valuation services, and a wealth management practice covering investment advisory, estate planning, and family office services for clients across multiple industries.

Differentiator

Problem solved

Functional benefit

Brands

• PMCF (Plante Moran Capital Finance): Investment Banking services
• Realpoint
• Living Forward
• PMFA (Plante Moran Financial Advisors)

Products and services

• Audit and Assurance Financial statement audits, employee benefit plan audits, SEC surprise audits, single audits, and international audit services delivered to clients across multiple industries including aerospace and defense, manufacturing, healthcare, financial services, government, and not-for-profit.
• Tax Services Federal, state, local, and international tax services covering personal tax, national corporate tax, M&A tax, transfer pricing, state and local tax, tax controversy, and tax credits, incentives, and deductions studies.
• Consulting Services Multi-disciplinary advisory including AI consulting, cybersecurity, data and analytics, ERP consulting, finance and accounting advisory, forensic accounting, investment banking (via PMCF), outsourced finance and accounting, restructuring and turnaround, risk management, strategy, supply chain and operations, technology consulting, transaction advisory, valuation, commercial real estate advisory (Realpoint), and senior living development consulting (Living Forward).
• Wealth Management Wealth management practice covering business transition services, estate planning, family legacy, family office services, financial planning, insurance, investment advisory, personal tax planning, and trust services for high-net-worth individuals and families. Operated through the PMFA (Plante Moran Financial Advisors) sub-brand, ranked No. 2 on Accounting Today's 2026 Top Firms by AUM list.

Segments9 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Partnerships

One partnership is on record.

• JA Del RíoflagshipStrategic or Co-development Partner · 1 May 2026Leading Mexico firm JA Del Río joined Plante Moran, expanding presence in Latin America and strengthening global capabilities. This represents a significant strategic expansion into the Mexican and broader Latin American market.

Scale indicators4 records

Recent moves4 records

Expansion highlights4 records

Broad incumbents

• Plante Moran: Top-10 US accounting and consulting firm offering audit, tax, consulting, and wealth management across multiple industries. Comparable as a multi-disciplinary mid-tier firm with integrated service lines, though materially larger than Tonneson + Co.
• BDO USA: One of the largest mid-tier accounting networks globally, offering assurance, tax, and advisory to mid-market clients. Directly comparable business model and target client segment to a regional firm like Tonneson + Co, but at national scale.
• Grant Thornton US: National mid-tier accounting firm serving dynamic mid-market clients with audit, tax, and advisory services. Same target segment and service-line breadth as Tonneson + Co.
• Crowe LLP: Major US accounting and consulting firm serving mid-market and large clients across industries. Comparable integrated audit/tax/advisory model with similar mid-market orientation.
• RSM US: Leading US mid-tier audit, tax, and consulting firm focused on middle-market companies. Closely comparable service mix, client segment, and partner-led delivery model to Tonneson + Co.

Direct peers

• Moss Adams: West Coast-headquartered mid-tier accounting firm of comparable size and service mix, focused on mid-market companies. Closely comparable regional mid-tier firm with similar size, services, and client profile to Tonneson + Co.
• Baker Tilly US: Mid-tier accounting and advisory firm serving mid-market clients across audit, tax, and consulting. Similar size and service breadth as a regional mid-tier firm.
• Withum Smith+Brown: Northeast-based top-30 US accounting and advisory firm with comparable size, service mix (audit, tax, advisory), and mid-market/HNW client base. Highly comparable regional mid-tier firm to Tonneson + Co.
• Wipfli LLP: Top-20 US accounting and consulting firm serving mid-market organizations, with comparable size and service-line breadth. Regional mid-tier competitor with similar client profile.
• Marcum LLP: Northeast-headquartered top-20 US accounting firm offering audit, tax, and advisory services. Most geography-comparable peer to Tonneson + Co, with similar mid-market and HNW client focus in the Northeast corridor.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat3 records

Key risks6 records

Key highlights5 records

Customer concentration

• Xx.com/tonnesonco
• Facebookfacebook.com/tonnesonco
• LinkedInlinkedin.com/company/tonneson---co

Revenue estimate

Valuation estimate

Number of profiles

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Tonneson + Co