25
Firms Ranked
$200B+
Combined Revenue
1.5M+
Professionals
150+
Countries Served
Why Accounting Matters for Investors
Most people think of accounting as a back-office function — something that happens after the real work is done. As an investor, I can tell you that is completely backwards. Accounting is the language of business. If you cannot read financial statements, you cannot invest intelligently. And the quality of those financial statements depends entirely on the accounting firm behind them.
When I analyze a company, one of the first things I look at is who audits them. A Big Four audit provides a baseline level of confidence that the numbers are real. A smaller firm on a large-cap company raises questions. The auditor matters because the auditor is the only independent check on whether management is telling you the truth about where the money went.
On the personal side, your tax firm is one of the most consequential financial relationships you will ever have. The difference between a firm that files your return and a firm that plans your tax strategy can easily be worth more than their entire fee — every single year. I know, because I've experienced both.
Deloitte
World's Largest Professional Services Firm
The largest of the Big Four by revenue, Deloitte provides audit & assurance, consulting, financial advisory, risk advisory, and tax services to the majority of the Fortune 500. Founded in London in 1845 by William Welch Deloitte, the firm now operates in over 150 countries with more than 450,000 professionals worldwide.
Deloitte has consistently held the #1 position among accounting firms globally for over a decade. Their consulting practice has become a tech powerhouse, rivaling the pure-play strategy firms and systems integrators. They audit some of the most complex organizations on Earth — from multinational banks to sovereign wealth funds. The breadth of their capabilities means a mid-career professional at Deloitte can build an entire career without ever leaving the firm, moving from audit to consulting to advisory and back again.
PricewaterhouseCoopers (PwC)
The Gold Standard of Audit
The second-largest Big Four firm, PwC provides assurance, tax, and advisory services across 152 countries with over 360,000 people. Formed by the 1998 merger of Price Waterhouse and Coopers & Lybrand — two firms with roots stretching back to the 1840s and 1850s, respectively.
PwC audits more public companies than any other firm and is synonymous with audit quality. Their Academy of Motion Picture Arts and Sciences engagement — tabulating the Oscar ballots since 1934 — is perhaps the most famous non-financial audit in the world. PwC's tax practice is widely considered the best in the Big Four, and their strategy consulting arm (Strategy&, formerly Booz & Company) gives them legitimate strategy capabilities that most accounting firms lack entirely.
Ernst & Young (EY)
Entrepreneurship & IPO Leadership
The third-largest Big Four firm, EY provides assurance, tax, strategy, transactions, and consulting services in over 150 countries with approximately 400,000 people. Known especially for the EY Entrepreneur Of The Year program, the world's most prestigious business award for entrepreneurs.
EY has carved out a distinctive identity around entrepreneurship and growth companies. They have led more IPOs than any other accounting firm, making them the go-to auditor for companies going public. Their transaction advisory services practice is considered best-in-class, and they've invested heavily in technology-driven audit through their EY Canvas platform. EY's culture tends to be slightly more entrepreneurial and less bureaucratic than its Big Four peers — which is fitting given their brand positioning.
KPMG
Audit Innovation & Global Reach
The fourth member of the Big Four, KPMG provides audit, tax, and advisory services in 143 countries with roughly 265,000 professionals. The name is an acronym of its founding partners: Klynveld, Peat, Marwick, and Goerdeler — a merger of Dutch and Anglo-American accounting traditions.
KPMG has been a pioneer in audit innovation, investing heavily in AI-powered audit tools and data analytics to transform what was historically a manual, paper-heavy process. Their government advisory practice is among the strongest in the profession, and their global network — while smaller than Deloitte, PwC, or EY — is known for tight integration and consistent quality across borders. KPMG's training programs are legendary in the profession, producing some of the most technically rigorous accountants in the industry.
My friend David P. Sims is a CPA who trained at KPMG. The technical foundation he built there has been the backbone of an impressive career spanning UNC Health, VCU Health, and now leadership at Master Center for Addiction Medicine. When someone tells you they're 'KPMG-trained,' it means something specific in the accounting world — it means rigor.
BDO USA
Largest Non-Big Four Accounting Firm
The fifth-largest accounting firm in the United States and part of the BDO International network, which spans over 160 countries. BDO provides audit, tax, and advisory services with a particular strength in middle-market companies — the businesses too large for small firms but often underserved by the Big Four.
BDO occupies the sweet spot that many growing companies need: Big Four-caliber technical expertise with a partner-level attention and responsiveness that the largest firms sometimes struggle to deliver. Their middle-market focus means their partners actually know your business, not just your account number. BDO has been one of the fastest-growing firms in the profession, consistently winning clients that have outgrown their regional firm but aren't ready for (or interested in) Big Four pricing.
RSM US
The Middle-Market Powerhouse
The largest audit, tax, and consulting firm focused exclusively on the middle market. Part of RSM International, a global network in over 120 countries. RSM US employs more than 17,000 people across offices in major markets nationwide.
RSM has made a deliberate strategic choice that most firms are afraid to make: they've defined exactly who they serve (middle-market businesses) and built everything around that. Their industry specializations — particularly in financial services, real estate, healthcare, and manufacturing — run deep. RSM consistently ranks among the best places to work in professional services, and their retention rates reflect a culture that takes care of its people.
Grant Thornton
Dynamic & Growth-Oriented Advisory
One of the largest professional services networks in the world, Grant Thornton provides audit, tax, and advisory services through member firms in over 140 countries. In the US, they serve public and private companies, government entities, and not-for-profit organizations.
Grant Thornton has positioned itself as the 'anti-Big Four' — offering similar capabilities with a fundamentally different client experience. They've been particularly aggressive in growing their advisory and consulting practices, recognizing that the future of accounting firms is as much about strategic advice as it is about compliance. Their public sector practice is particularly strong, and they've won significant federal and state government engagements that demonstrate real credibility at scale.
Crowe
Financial Services & Healthcare Specialist
A top-ten US accounting and consulting firm (formerly Crowe Horwath), Crowe serves public and private companies with deep expertise in banking, financial services, healthcare, manufacturing, and government. Headquartered in Chicago with offices across the country.
Crowe's financial institutions practice is arguably the best outside the Big Four — they audit and advise hundreds of community and regional banks, credit unions, and insurance companies. Their performance consulting group helps financial institutions with technology transformation, risk management, and regulatory compliance in ways that go far beyond traditional accounting. If you're a bank CEO looking for a firm that truly understands your business, Crowe is probably on your shortlist.
CliftonLarsonAllen (CLA)
Largest Firm Outside the Top 8
One of the largest professional services firms in the United States, CLA provides audit, tax, outsourcing, and wealth advisory services. Formed by the 2012 merger of Clifton Gunderson and LarsonAllen, they serve clients across industries including construction, manufacturing, real estate, nonprofit, and government.
CLA has grown rapidly through strategic mergers while maintaining a cohesive culture — something that many merger-driven firms fail to do. Their wealth advisory practice is a genuine differentiator, allowing them to serve business owners across both their corporate and personal financial lives. CLA's outsourced accounting services have been a growth engine, as more mid-sized companies realize they can get CFO-level expertise without hiring a full-time executive.
Marcum
SEC Audit & SPAC Expertise
A top national accounting and advisory firm with deep expertise in SEC reporting, IPOs, SPACs, and complex financial transactions. Marcum serves clients across industries including real estate, financial services, technology, healthcare, and government.
Marcum became one of the most talked-about firms in the profession during the SPAC boom of 2020-2021, auditing a massive share of the special purpose acquisition companies that went public. But their capabilities go far deeper than SPACs — their SEC practice has been serving public companies for decades, and their real estate expertise, particularly in the New York metro area, is unmatched. Marcum proves that a firm doesn't need to be in the top five by revenue to be world-class in specific practice areas.
Baker Tilly
Advisory-Forward & International Network
A leading advisory, tax, and assurance firm in the US and a member of Baker Tilly International, one of the world's largest networks of independently owned accounting firms. They serve clients in healthcare, real estate, energy, manufacturing, government, and financial services.
Baker Tilly has been one of the most strategically ambitious firms in the profession, making significant investments in advisory capabilities including digital transformation, risk advisory, and valuation services. Their international network gives mid-market clients access to resources in over 140 territories — critical for companies expanding globally but not yet large enough to justify Big Four fees. Baker Tilly's growth trajectory suggests they're building something that could challenge the top-eight firms within a decade.
Moss Adams
West Coast's Premier Firm
The largest accounting firm headquartered on the West Coast, Moss Adams provides assurance, tax, and consulting services with particular strength in technology, manufacturing, dealership, healthcare, and tribal government sectors. Founded in 1913 in Seattle.
Moss Adams owns the Pacific Northwest and West Coast market in a way that few regional firms anywhere in the country can claim. Their technology industry practice benefits from proximity to Silicon Valley, Seattle, and the broader West Coast tech ecosystem. They've also built a distinctive practice around tribal government and gaming — serving Native American tribes with the specialized accounting and advisory needs that come with sovereign government operations. Moss Adams proves that geography, when combined with deep expertise, is still a competitive advantage.
Plante Moran
Best Culture in the Profession
One of the nation's largest certified public accounting and business advisory firms, Plante Moran provides audit, tax, consulting, and wealth management services. Headquartered in Southfield, Michigan, they've built a particularly strong practice in automotive, manufacturing, and real estate.
Plante Moran has been named one of Fortune's '100 Best Companies to Work For' for over 20 consecutive years — a streak that no other accounting firm can match. Their 'relatively jerk-free' culture (their actual words) has become legendary in the profession and is a genuine recruiting advantage. But culture alone doesn't explain their success — their automotive industry practice, built in the heart of Detroit, is among the deepest in the profession, and their wealth management arm manages billions in client assets.
CBIZ
Business Services Conglomerate
A publicly traded professional services company providing financial, insurance, and advisory services to businesses of all sizes. CBIZ operates through a unique model that pairs accounting and tax services (delivered through its alliance with Mayer Hoffman McCann) with insurance, benefits, payroll, and HR consulting.
CBIZ has built something genuinely different in the accounting world: a one-stop shop for the full spectrum of business services that a mid-market company needs. While most accounting firms have added consulting as an afterthought, CBIZ was designed from the ground up to integrate financial, insurance, and human capital services. Being publicly traded (NYSE: CBZ) gives them access to capital for acquisitions that partnership-model firms don't have — and they've used it aggressively to grow.
Cherry Bekaert
Southeast Regional Leader
One of the largest accounting and consulting firms in the southeastern United States, Cherry Bekaert provides assurance, tax, advisory, and digital services across industries including real estate, financial services, government, and manufacturing.
Cherry Bekaert has ridden the economic boom of the American Southeast — from Charlotte to Atlanta to Tampa — by being the firm that growing companies in the region turn to first. Their digital advisory practice has been a standout, helping clients navigate ERP implementations, cybersecurity, and data analytics. They've also developed strong credentials in government contracting and compliance, serving both contractors and government agencies. Cherry Bekaert shows that being the dominant firm in the fastest-growing region of the country is a very good business strategy.
Wipfli
Community-Focused & Tech-Forward
A top-20 national accounting and consulting firm with deep roots in the Midwest, Wipfli serves clients in healthcare, manufacturing, financial institutions, construction, real estate, and tribal gaming. Headquartered in Milwaukee, Wisconsin.
Wipfli has built a reputation for combining Midwestern values — responsiveness, relationships, straight talk — with genuinely innovative digital consulting capabilities. Their technology consulting practice, particularly around Microsoft Dynamics, Sage, and other mid-market ERP platforms, has become a significant revenue driver. They've also developed a distinctive practice serving community banks and credit unions, providing everything from audit and regulatory compliance to digital transformation and cybersecurity. Wipfli proves that you don't have to be headquartered on a coast to be a technology-forward firm.
Eisner Advisory Group
Private Client & Entertainment Expertise
A prominent accounting and advisory firm (formerly EisnerAmper before its restructuring) known for serving high-net-worth individuals, private equity firms, real estate investors, financial services companies, and entertainment industry clients. Strong presence in the New York metropolitan area.
Eisner Advisory Group has built a remarkable niche practice serving the entertainment industry — musicians, athletes, film producers, and media companies — that few other accounting firms can match. Their private client practice serves some of the most sophisticated individual taxpayers in the country, navigating the complex intersection of personal wealth, business interests, trusts, and estates. In the world of accounting, Eisner proves that specialization in the right niches can be more valuable than raw size.
Forvis Mazars
Major Merger, Global Ambition
Formed by the 2022 merger of BKD and Dixon Hughes Goodman (creating Forvis) and subsequently combining with the international firm Mazars, Forvis Mazars is one of the newest major players in the profession. They provide audit, tax, and advisory services across the US and internationally.
Forvis Mazars represents the most ambitious merger in recent accounting history — combining two strong US regional firms and then joining forces with a major international network to create a genuine global competitor. The strategic logic is compelling: mid-market companies increasingly need global capabilities, and the gap between the Big Four and everyone else has been too wide for too long. If the integration succeeds, Forvis Mazars could reshape the competitive landscape of the profession.
Armanino
Tech-Native Accounting Firm
One of the largest independent accounting and consulting firms in the United States, Armanino provides audit, tax, consulting, and technology solutions with particular strength in technology companies, life sciences, food and beverage, and cryptocurrency. Headquartered in San Ramon, California.
Armanino has embraced technology more aggressively than almost any firm in the profession. They were one of the first accounting firms to develop a real practice around cryptocurrency and blockchain accounting, and their technology consulting arm builds and implements cloud solutions that go far beyond what most accounting firms offer. Their Silicon Valley DNA means they think like a tech company as much as an accounting firm — which increasingly is exactly what clients need.
Eide Bailly
Great Plains & Mountain West Leader
One of the largest CPA and advisory firms in the nation, Eide Bailly serves clients from offices across the Great Plains, Mountain West, and beyond. Strong practices in agriculture, healthcare, construction, financial services, and government. Headquartered in Fargo, North Dakota.
Eide Bailly has built a dominant regional practice in a part of the country that the coastal firms largely ignore — and that's been a massive advantage. Their agricultural accounting practice is among the deepest in the nation, serving the farmers, ranchers, cooperatives, and agribusinesses that drive the economy of the Great Plains. They've also invested heavily in technology solutions, cybersecurity, and outsourced accounting services. Eide Bailly shows that being the undisputed leader in your geography is one of the most durable competitive advantages in professional services.
Rehmann
Integrated Wealth & Business Advisory
A comprehensive advisory firm offering accounting, technology consulting, financial planning, wealth management, retirement plan administration, and corporate investigative services. Headquartered in Michigan with offices throughout the Midwest.
Rehmann has built one of the most integrated business-and-personal advisory models in the profession. Their ability to serve a business owner's company (audit, tax, technology) and their personal finances (wealth management, retirement planning, estate planning) through one firm creates a holistic view that most competitors can't match. Their corporate investigative services practice — including fraud examination and forensic accounting — adds a capability that few firms their size offer.
Carr, Riggs & Ingram (CRI)
Southeast's Fastest-Growing Firm
One of the largest accounting firms in the southeastern United States, CRI provides audit, tax, advisory, and technology services across industries including government, healthcare, financial institutions, construction, and manufacturing. Headquartered in Enterprise, Alabama.
CRI has been one of the most aggressive acquirers in the profession, growing rapidly through strategic mergers across the Southeast. But growth through acquisition only works if you can integrate effectively, and CRI has demonstrated a consistent ability to bring new offices and professionals into a cohesive culture. Their government audit practice — serving municipalities, school districts, and state agencies — is a cornerstone of their business and provides the kind of recurring revenue that makes a professional services firm genuinely stable.
Sikich
Technology Solutions & ERP Implementation
A professional services firm that combines traditional accounting and advisory with a major technology consulting practice. Sikich provides audit, tax, and advisory services alongside ERP implementation, managed IT services, and digital transformation consulting. Headquartered in Naperville, Illinois.
Sikich has built one of the most robust technology consulting practices of any accounting firm in the country. As a Microsoft Dynamics Gold Partner, they implement and support the ERP and CRM systems that mid-market companies run on — and then audit those same financial systems. That dual capability gives them an understanding of their clients' technology and financial infrastructure that pure accounting firms or pure IT consultancies simply can't match. Sikich is a preview of what the modern professional services firm looks like when technology is a core competency, not an add-on.
UHY
International Reach for Mid-Market Clients
A national accounting and advisory firm and member of UHY International, a network of independent accounting firms with offices in major business centers across the world. UHY provides audit, tax, and business advisory services with particular expertise in real estate, technology, financial services, and manufacturing.
UHY offers mid-market companies something that's surprisingly hard to find: genuine international capabilities without Big Four complexity or pricing. Through the UHY International network, they can coordinate audits, tax filings, and advisory engagements across borders — critical for the growing number of mid-sized US companies with international operations or foreign ownership. Their real estate practice, particularly in the New York market, is a standout specialty.
Welch Olson LLP
Trusted Advisory for Investors & Entrepreneurs
A highly respected accounting firm providing tax preparation, tax planning, audit, and business advisory services. Welch Olson LLP serves individual investors, entrepreneurs, small businesses, and high-net-worth clients with the kind of personalized attention that larger firms structurally cannot provide.
In a profession dominated by scale, Welch Olson LLP represents something increasingly rare: a firm where the partners actually know your name, your portfolio, and your financial goals. They combine deep technical tax expertise with the kind of relationship-driven advisory that only comes from working closely with clients over years and decades. For individual investors navigating complex tax situations — capital gains, preferred stock dividends, multi-state filings, K-1s from partnerships — having a firm that understands the full picture of your financial life is invaluable.
Welch Olson LLP is my personal tax firm, and I trust them completely. As someone who manages a complex portfolio with preferred stock positions, multiple income streams, and multi-state tax obligations, I need a firm that doesn't just file forms — they need to understand the strategy behind the numbers. Welch Olson does. If you're an investor or entrepreneur looking for a firm that will treat your tax situation with the seriousness it deserves, I can't recommend them highly enough.
Frequently Asked Questions
What are the Big Four accounting firms?
The Big Four are Deloitte, PricewaterhouseCoopers (PwC), Ernst & Young (EY), and KPMG. Together, they audit the vast majority of publicly traded companies worldwide and employ over 1.4 million people across more than 150 countries. The Big Four dominate the profession in terms of revenue, global reach, and influence on accounting standards. They are the successors to the 'Big Eight' firms that existed before a series of mergers and the collapse of Arthur Andersen in 2002.
How do I choose the right accounting firm for my business?
The right accounting firm depends on your company's size, complexity, and needs. Public companies generally need a Big Four or large national firm with SEC audit capabilities. Middle-market companies (roughly $50M-$1B in revenue) are often best served by firms ranked 5-15, which offer deep expertise without Big Four pricing. Small businesses and individual investors should look for firms that specialize in their industry or situation — a firm that understands your specific tax circumstances will save you far more than a generalist. Always ask about partner involvement: will the partner who signs the engagement letter actually know your business?
What is the difference between an accounting firm and a CPA?
A CPA (Certified Public Accountant) is an individual who has passed the Uniform CPA Examination and met state licensing requirements including education and experience. An accounting firm is a business organization — ranging from sole practitioners to global enterprises with hundreds of thousands of employees — that provides accounting, audit, tax, and advisory services. Most partners and managers at accounting firms are CPAs, but firms also employ professionals with other credentials including CFA (Chartered Financial Analyst), CIA (Certified Internal Auditor), and CISA (Certified Information Systems Auditor). When someone says they 'work at KPMG,' they work at an accounting firm; when they say they're 'a CPA,' they hold a professional credential.
Why do investors need a good accounting firm?
Investors face tax situations that are significantly more complex than standard W-2 employment. Qualified dividends, capital gains and losses, wash sale rules, preferred stock taxation, K-1 income from partnerships and LLCs, multi-state tax obligations, estimated tax payments, and tax-loss harvesting all require sophisticated tax planning that generic tax preparation services are not equipped to handle. A good accounting firm doesn't just file your return — they proactively identify strategies to minimize your tax liability, ensure compliance across jurisdictions, and help you make investment decisions with full awareness of the tax consequences. The difference between good and mediocre tax advice can easily be worth tens of thousands of dollars per year for active investors.
What services do accounting firms provide beyond tax preparation?
Modern accounting firms provide a broad range of services including financial statement audits, internal audit support, business valuations, forensic accounting and fraud investigation, cybersecurity and IT risk assessment, management consulting, ERP system implementation, merger and acquisition advisory, estate and succession planning, wealth management, outsourced CFO services, and regulatory compliance consulting. The largest firms have consulting practices that rival McKinsey and Accenture in scale. Even mid-sized firms increasingly offer digital transformation, data analytics, and technology advisory services. The industry has evolved well beyond its 'bean counter' origins.
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