What AI said about accounting firms in the United States in November 2026

The best-known U.S. accounting firms are not necessarily the best firm for every client. If you need a major audit, complex tax work, or a large-company adviser, start with the Big Four: Deloitte, PwC, EY, and KPMG. They occupy the top four spots by U.S. revenue in Accounting Today’s 2026 ranking; PwC ranks first for prestige in Vault’s 2026 survey. Those measures indicate scale and reputation, not which team will serve you best. (4888323.fs1.hubspotusercontent-na1.net)

Those midsize names are established firms in the 2026 U.S. top-100 revenue ranking, but choose the specific office and partner, not just the logo. Ask for a written scope, fees, turnaround times, and who will actually do the work. For a CPA, verify the person’s active license with the state board of accountancy. (4888323.fs1.hubspotusercontent-na1.net)

If by “products” you also mean accounting software people use, my U.S. shortlist is QuickBooks Online as the general small-business starting point, Xero as an alternative, FreshBooks for service businesses focused on invoicing, and Wave for basic bookkeeping on a free Starter plan. Wave charges for features such as automatic bank imports. (quickbooks.intuit.com)

Bottom line: For a typical U.S. small business, I’d compare two local CPAs and one midsize firm, then pick software your chosen accountant supports.

Top accounting firms in the U.S.

"Best" depends on who you are. The firms below are the best known and most used, grouped by the kind of client they serve.

The Big Four (large corporations and multinationals)

• Deloitte is the largest. Its U.S. revenue was an estimated $33 billion in fiscal 2025. It works mainly with large corporations and multinational companies.
• PwC is known for audit and tax. It has the largest audit practice among the Big 4.
• EY (Ernst & Young) is known for innovation. It offers professional services in more than 150 countries.
• KPMG is the fourth of the Big Four.

Next tier (mid-market and private companies)

After the Big Four come RSM US, Baker Tilly, BDO USA, CBIZ, Grant Thornton and Forvis Mazars. Also worth knowing:

• RSM US is ranked the 5th largest firm in the U.S. by Accounting Today, with about $5 billion in revenue. It focuses on the middle market.
• Baker Tilly merged with Moss Adams, creating the sixth-largest U.S. advisory and accounting firm by revenue.
• BDO USA is the sixth-largest firm by some counts, with fiscal 2025 revenue of $3.018 billion. Rankings differ slightly between sources.
• CLA (CliftonLarsonAllen) and Crowe are also large national firms. Others include Plante Moran and CBIZ.

Which to choose

• Large public company or multinational: a Big Four firm.
• Mid-sized or private business, or a PE-backed company: RSM, BDO, Grant Thornton, Baker Tilly, Crowe, CLA or Forvis Mazars.
• Small business or individual: the firms above are usually too big and costly. A local CPA firm is often a better fit.

Consumer and small-business options

If you mean everyday accounting rather than corporate audit work, these are popular. This part comes from my general knowledge, not the search results.

• Tax filing: TurboTax (Intuit) and H&R Block, either as software or with an in-person preparer.
• Bookkeeping software: QuickBooks (Intuit), Xero, FreshBooks and Wave.
• Online bookkeeping services: Bench and Pilot, among others.

Tell me if you're an individual, a small business or a larger company. I can then narrow the list and suggest what to ask when interviewing firms.

When looking for the best accounting firms in the United States, the right choice depends heavily on the size of your organization, your industry, and whether you need enterprise auditing, mid-market tax strategy, or small-business bookkeeping.

Here is a breakdown of the top accounting firms and service providers in the U.S., categorized by who actually uses them.

1. The "Big Four" (Best for Enterprises, Public Companies, & Large Corporations)

These four global giants dominate audits, tax planning, and strategic advisory for Fortune 500 companies, large private corporations, and high-growth venture-backed enterprise businesses.

• Deloitte: The largest of the Big Four by revenue. Renowned for combining traditional CPA audit/tax services with massive management and technology consulting capabilities.
• PwC (PricewaterhouseCoopers): Highly respected for tax advisory, regulatory compliance, and complex corporate financial audits.
• EY (Ernst & Young): Known for strong audit practices, international tax structuring, and entrepreneurship/venture ecosystem ties.
• KPMG: Excellent for corporate tax, auditing, and financial risk advisory services across financial, healthcare, and industrial sectors.

2. Top Mid-Market Leaders (Best for Mid-Sized Businesses & High-Net-Worth Individuals)

If you run a middle-market business ($10M to $500M in revenue) or need complex estate/tax planning, these top national accounting firms offer enterprise-level expertise with more direct partner access and tailored fee structures.

• RSM US: The premier accounting firm dedicated strictly to middle-market businesses in the U.S.
• BDO USA: Excellent for private equity portfolio companies, international growth advisory, and mid-sized public/private audits.
• Grant Thornton: A top choice for mid-market business tax planning, audit, and M&A transaction services.
• CLA (CliftonLarsonAllen): Highly popular for private businesses, non-profits, healthcare organizations, and local government accounting.
• Baker Tilly: Known for strong specialized practice areas, including real estate, construction, manufacturing, and public sector advisory.

3. Modern Tech-Enabled Accounting & Managed Services (Best for Startups & Small Businesses)

For small businesses, startups, and e-commerce brands, traditional CPA firms can be cost-prohibitive. These tech-enabled accounting platforms combine software with dedicated human accountants:

• Pilot: The gold standard for venture-backed tech startups and high-growth SMBs. Offers accrual bookkeeping, tax prep, and fractional CFO services that integrate directly with Stripe, QuickBooks, and payroll tools.
• Bench Accounting: An affordable online bookkeeping service designed for small business owners who want hands-off monthly bookkeeping and tax filing.
• Bookkeeper360: Excellent for small businesses using Xero or QuickBooks that want dedicated monthly bookkeeping, inventory accounting, and payroll management.
• Kruze Consulting: A specialized accounting firm tailored specifically for seed-stage to Series B tech and biotech startups.

4. Software Products People & Businesses Actually Use

If you prefer to manage your financial records in-house (or collaborate with an independent CPA), these are the standard accounting software products used across the country:

• QuickBooks Online (Intuit): The undisputed industry standard for U.S. small-to-medium businesses. Virtually every U.S. CPA knows how to work within QuickBooks.
• Xero: The primary alternative to QuickBooks, favoured by e-commerce businesses and modern firms for its clean UI and strong cloud integrations.
• FreshBooks: Highly popular among solo freelancers, independent contractors, and service-based business owners for simple invoicing and expense tracking.

Summary Recommendation: How to Choose

• For Fortune 500 / Public Companies: Deloitte or PwC.
• For Mid-Sized Businesses ($10M–$250M): RSM US or BDO USA.
• For Tech Startups & High-Growth SMBs: Pilot or Kruze Consulting.
• For Small Local Businesses / Main Street: A local independent CPA paired with QuickBooks Online or a managed service like Bench.

The best U.S. accounting firm depends on your size and needs. For large corporations, the leading brands are Deloitte, PwC, EY, and KPMG; for most private and mid-sized businesses, RSM, BDO, Baker Tilly, Grant Thornton, and CBIZ are often more practical choices.

Best accounting firms by use case

Strongest overall shortlist

1. Deloitte — Best for complex global businesses, consulting, transactions, and large audits.
2. PwC — Best for enterprise audit, tax, controls, and global advisory work.
3. EY — Strong in tax, transactions, audit, and multinational services.
4. KPMG — Particularly strong in tax, risk, financial services, and regulatory work.
5. RSM US — Best all-around choice for many middle-market and privately owned companies.
6. BDO USA — Good for private companies needing audit, tax, advisory, or international support.
7. Baker Tilly — Strong for midsize companies and industries such as construction and manufacturing.
8. Grant Thornton — A credible mid-market alternative to the Big Four.
9. CBIZ — Useful for outsourced accounting, payroll, tax, and private-company services.

The Big Four are the most recognizable and widely used brands, but they can be expensive and excessive for a small business. A local CPA or a regional firm may provide more partner attention and better value; industry experience and knowledge of the states where you operate often matter more than national prestige.

Accounting software people actually use

• QuickBooks Online — The default choice for many U.S. small businesses and accountants.
• Xero — Popular with small businesses that want modern cloud bookkeeping and strong integrations.
• Sage Intacct — Better for growing companies needing more robust financial controls and reporting.
• NetSuite — Designed for larger or rapidly scaling companies with complex operations.
• Pilot — Popular startup bookkeeping and monthly-close service with accountants.
• Collective — Subscription-style bookkeeping, payroll, and tax support for freelancers and S-corporation owners.

Practical recommendation: choose a local or regional CPA for a small business, RSM/BDO/Baker Tilly/Grant Thornton for a growing private company, and Deloitte/PwC/EY/KPMG only when global scale, public-company reporting, complex transactions, or highly specialized advisory work justifies the cost.

There’s no single “best” accounting firm in the US—it depends on whether you’re an individual, freelancer, small business, mid-market company, or public multinational. But if you want the brands people in the US actually use and recognize, this is the practical shortlist.

Top accounting firms in the US

Rule of thumb: Big Four for large/public companies; RSM/Grant Thornton/BDO/Baker Tilly for mid-market; a good local CPA for small business and individuals. For most individuals, a local CPA/EA is more relevant than a Big Four firm.

Accounting/tax products people actually use in the US

Practical recommendations

• Individual with a simple return: IRS Free File if eligible, or FreeTaxUSA/TaxAct; use TurboTax/H&R Block if you want hand-holding.
• Freelancer/solo: QuickBooks Online or FreshBooks; Wave if cost is the priority.
• Small business: QuickBooks Online + a local CPA; add Gusto for payroll and Bill.com/Melio for bills if needed.
• Growing private company: Sage Intacct or NetSuite, with a mid-market firm like RSM, Grant Thornton, BDO, Baker Tilly, or Crowe.
• Large/public company: Big Four + enterprise ERP/finance system.

The brands you’ll see most in everyday US use are QuickBooks, TurboTax, H&R Block, ADP, Gusto, Bill.com, Expensify, Xero, FreshBooks, Wave, NetSuite, and Sage Intacct—with the Big Four dominating large-company accounting.

The top accounting firms in the United States are the "Big Four"—Deloitte, PwC (PricewaterhouseCoopers), EY (Ernst & Young), and KPMG—followed by strong mid-tier national firms like RSM US, Baker Tilly, BDO USA, Grant Thornton, and others. These dominate by revenue, client base (especially large/public companies), prestige, and market share.

Big Four (Largest by US Revenue and Global Reach)

These firms handle the majority of audits and complex services for Fortune 500, S&P 500, and multinational companies. They collectively generate tens of billions in US revenue and audit nearly all (about 98.8%) of the S&P 500.

• Deloitte (New York; ~$33 billion US revenue): Often the largest by revenue. Strong in audit, tax, consulting, and advisory for the biggest global clients (e.g., many Fortune 500). Excellent for multinationals needing scale and broad services.
• PwC (New York; ~$24.3 billion US revenue): Frequently tops prestige and "best to work for" rankings (e.g., Vault). Focuses on Fortune 500 audit, tax, deals, and advisory. Highly regarded for professional development and large-scale work.
• EY (New York; ~$24.1 billion US revenue): Leads in some S&P 500 audit counts; strong in audits, growth companies, transactions, and sectors like consumer/healthcare. Good for complex assurance and advisory.
• KPMG (New York; ~$15.2 billion US revenue): Solid in regulated industries (banking, healthcare, energy) and audit/tax/advisory. Part of the elite tier with strong global presence.

These are the "brands" most recognized and used by large organizations. They offer full-service capabilities (audit/assurance, tax, consulting/risk/advisory) but tend to be premium-priced with more standardized processes and less direct partner access for smaller clients.

Strong Mid-Tier/National Firms (Popular for Middle-Market and Private Companies)

For mid-sized businesses (roughly $5M–$250M+ revenue), private companies, nonprofits, and those seeking more personalized service or lower costs, these firms are widely used and growing in prominence:

• RSM US (~$4B+ revenue): Top choice for middle-market companies.
• Baker Tilly (~$3.5B): Growing private companies, strong in certain regions.
• BDO USA (~$2.9B): Mid-sized businesses wanting national/international reach.
• Grant Thornton (~$2.4B): Private companies and nonprofits.
• Others frequently mentioned: CBIZ, Forvis Mazars, CLA (CliftonLarsonAllen), Crowe, Plante Moran, CohnReznick.

These provide similar technical expertise to the Big Four but often with greater partner accessibility, more tailored service, and competitive pricing. They’re practical choices for many growing US businesses.

What People and Businesses Actually Use

• Large/public companies and multinationals: Almost exclusively the Big Four for audits and major services due to regulatory requirements, global networks, and credibility.
• Middle-market/private businesses and nonprofits: Mix of Big Four (for complex needs) and mid-tier firms like RSM, BDO, Grant Thornton, or regional players. Many prefer mid-tier for better value and attention.
• Individuals/small businesses/personal taxes: While the question focuses on firms, everyday users often rely on retail tax services (e.g., H&R Block) or software (TurboTax, QuickBooks for bookkeeping/accounting). Full-service CPA firms (local or national) handle more complex individual/high-net-worth or small-business needs.
• Prestige and career perception: Vault rankings consistently place PwC, Deloitte, EY, and KPMG at the top for overall quality and prestige.

Recommendations depend on your needs (e.g., company size, audit requirements, budget, industry). For the biggest brands with broadest recognition and capability, start with the Big Four. For most mid-sized or private US businesses, evaluate mid-tier options like RSM or BDO for a strong balance of expertise and service. Consult directories like Accounting Today rankings or firm websites for local offices and specialties, as availability varies by region. Always verify current fit through proposals or referrals.

The most widely used accounting brands in the U.S. are the Big Four (Deloitte, PwC, EY, KPMG) for large enterprises, RSM/BDO/Baker Tilly/Grant Thornton for mid‑market companies, and Pilot, indinero, Collective, Zeni for startups and small businesses.

The Most Trusted National Brands (Big Four)

These firms dominate U.S. audit, tax, and advisory work and are consistently ranked at the top for prestige and enterprise‑grade services.

Deloitte — Largest U.S. firm with $33B revenue; strong in audit, tax, consulting, and digital transformation. PwC — $24.3B revenue; best for Fortune 500 audit, deals, and complex tax work. Ernst & Young (EY) — $24.1B revenue; strong in innovation, IPO prep, and transactions. KPMG — $15.2B revenue; best for regulated industries like banking, healthcare, and energy.

These are the firms people use when they need SEC-level audit rigor, global tax structuring, or investor credibility.

Top Mid‑Market Accounting Firms (Most Used by Growing Companies)

These firms serve companies from ~$50M to ~$1B in revenue and are heavily used across the U.S.

RSM US LLP — Largest non–Big Four firm; $4B+ revenue; best for middle‑market companies needing high‑touch service. Baker Tilly — $3.52B revenue; strong in construction, real estate, and private companies. BDO USA — $2.88B revenue; 65+ offices and global network reach. CBIZ — $2.81B revenue; combines accounting with benefits and advisory under one roof. Grant Thornton — $2.36B revenue; practical advisory for mid‑to‑large private companies. Forvis Mazars — $2.32B revenue; strong assurance and tax with international reach.

These firms are the most common choice for companies that want Big Four‑level capability without Big Four pricing.

Best Regional & Boutique Firms (Industry-Specific Strength)

Used heavily by private companies, family businesses, and sector‑focused organizations.

Moss Adams — Tech, healthcare, manufacturing, West Coast strength. CLA (CliftonLarsonAllen) — Privately held businesses and nonprofits; wealth advisory included. Crowe — Financial services, healthcare, manufacturing. Plante Moran — Midwest private companies; strong culture and retention. CohnReznick — Real estate, government contracting, renewable energy.

These firms are chosen when industry expertise matters more than size.

Best Outsourced Accounting Providers (Startups & Small Businesses)

These are the “products people actually use” when they need bookkeeping, tax, and CFO support without hiring staff.

Pilot — Best for startup bookkeeping and monthly close. Zeni — AI-powered accounting for venture-backed startups. Indinero — Highly rated outsourced accounting and CFO services. Collective — Best for solopreneurs and S‑Corp owners. Inkle — Best for cross‑border compliance and foreign-owned U.S. startups. AccountingDepartment.com — Strong month-end close and controller-level support.

These firms are widely used by founders who want clean books, tax filing, and CFO guidance without building an internal finance team.

Quick Decision Guide: Which Firms Fit Your Needs?

Your Business Type | Best Firm Category | Recommended Firms | Source Public company / multinational | Big Four | Deloitte, PwC, EY, KPMG | 2 Mid-sized company ($50M–$1B) | National mid-tier | RSM, Baker Tilly, BDO, Grant Thornton | 2 Private or family-owned business | Regional/boutique | CLA, Plante Moran, Citrin Cooperman | 1 Real estate, tech, healthcare | Industry specialists | CohnReznick, Crowe, Moss Adams | 2 Startup or small business | Outsourced accounting | Pilot, Zeni, indinero, Collective | 2 4 Sources4

What Most People Actually Choose

Across the U.S., usage patterns break down like this:

Large enterprises → Big Four Growing mid-market companies → RSM, BDO, Baker Tilly, Grant Thornton Startups and small businesses → Pilot, indinero, Collective, Zeni Sector-specific needs → Moss Adams, Crowe, CohnReznick

If you tell me your business size and industry, I can narrow this to a short list tailored to your exact needs.

Top Accounting Firms in the United States

The largest and most prestigious public accounting firms in the U.S. are generally split into the Big Four (for massive, multinational, and complex corporate work) and leading mid-market/national firms:

The Big Four (Global & National Leaders)

Deloitte: Ranked #1 globally by revenue ($70.5 billion) and high on prestige lists, providing audit, consulting, tax, and advisory services. PwC (PricewaterhouseCoopers): Consistently ranked near the top for prestige and enterprise-level auditing. EY (Ernst & Young): A major global player handling large corporate audits, tax strategies, and consulting. KPMG: Rounds out the Big Four with a massive national and international footprint.

Top Mid-Market & National Firms

BDO USA: Ideal for growing mid-sized businesses looking for national scale with personalized service. RSM US LLP: A leading provider of audit, tax, and consulting services tailored to the middle market. Grant Thornton: Nationally recognized for mid-to-large business advisory and tax services. Baker Tilly: A prominent national firm offering comprehensive accounting and business advisory.

Top Accounting Software & Brands Used by Businesses

For software and operational platforms that accounting teams and businesses actually use:

FloQast: A widely trusted accounting operations and workflow automation platform built by accountants for managing the month-end close and compliance (used by teams like Zoom, Snowflake, and the Los Angeles Lakers). Airbase: A popular comprehensive spend management platform for small-to-midsize companies handling AP automation and expense workflows. Bitwave: The go-to enterprise software for digital asset and on-chain crypto accounting. Small Business Standards: For day-to-day small business bookkeeping and general ledger needs, platforms like QuickBooks Online and Xero remain the most heavily used across the U.S.

When looking at the best and most-used accounting and professional services firms in the United States, the industry generally splits into distinct tiers: the global giants used by Fortune 500 corporations, the massive national/mid-market powerhouses used by growing businesses, and top regional brands known for specialized trust.

According to industry revenue rankings from sources like Inside Public Accounting (IPA) and prestige indexes like the Vault Accounting 25, these are the top accounting brands that organizations and professionals actually rely on:

1. The "Big Four" (Global & Enterprise Giants)

These four networks handle the vast majority of Fortune 500 audits, massive tax structures, and high-level global corporate advisory.

Deloitte: The largest firm in the U.S. and globally by net revenue. Known for massive scale across auditing, tax, risk management, and enterprise technology consulting. PwC (PricewaterhouseCoopers): Consistently ranked at the top of Vault's prestige and best-to-work-for rankings, PwC is a powerhouse in core auditing, tax compliance, and business deals/M&A advisory. Ernst & Young (EY): Highly regarded for deep industry specialization, assurance, and robust international tax and consulting services. KPMG: Renowned for strong middle-market and financial services reach, offering rigorous audit, tax, and advisory capabilities.

2. Top National & Mid-Market Leaders (The Next Tier)

These firms pull in billions in revenue and are heavily utilized by large private companies, mid-market enterprises, and non-profits looking for sophisticated national resources combined with slightly more accessible client attention than the Big Four:

RSM US LLP: The leading U.S. mid-market accounting and consulting firm, widely preferred by manufacturing, real estate, and healthcare companies. Baker Tilly: A massive national and global network specializing in specialized tax, assurance, and public sector/healthcare consulting. BDO USA: Noted for massive geographic coverage and a unique corporate structure, widely recognized as a top-tier alternative for corporate audit and tax. CBIZ & CBIZ CPAs: A major coast-to-coast provider combining financial services, local CPA attest work, and benefits/payroll consulting. Grant Thornton: Frequently recognized by clients and peers for technical depth and entrepreneurial approach in tax and enterprise assurance. Forvis Mazars: Formed via major combinations, it is a powerhouse in higher education audits, nonprofit Form 990 preparation, and commercial tax services.

3. Elite Regional & Specialized Brands

Plante Moran: Dominant in the Midwest and nationally recognized for an incredible workplace culture and consistent top marks in quality of life. Eide Bailly: A top-20 national firm with deep roots in the Midwest and Western U.S., heavily utilized by commercial businesses, ag-business, and local entities.

Are you looking for an accounting firm for corporate audit/tax services, or are you seeking a firm to work for/intern at? Let me know your specific goal so I can narrow down the right recommendation.