The accounting industry in the USA includes firms of very different sizes. The Big Four handle a large share of audit, tax and advisory work for major companies, while firms such as RSM US, Baker Tilly and BDO USA have a strong presence in the middle market.
These firms do more than prepare financial statements. Their work covers audit, tax, consulting, financial advisory, risk management and other business services. Some have a large Fortune 500 client base, while others focus more closely on middle-market companies.
This article covers 10 of the largest accounting firms in the USA based on the net revenue figures provided in the source material. The list includes the Big Four along with several major firms outside that group. Revenue figures can vary by reporting period and source, so they should be read as approximate figures rather than exact current totals.
Quick Look at the Top 10 Accounting Firms in the USA
| Rank | Accounting Firm | Headquarters | Net Revenue | Main Work |
| 1 | Deloitte | New York, NY | ~$35.69 billion | Audit, tax, consulting and financial advisory |
| 2 | PwC | New York, NY | ~$25.57 billion | Assurance, tax and advisory |
| 3 | Ernst & Young (EY) | New York, NY | ~$24.74 billion | Assurance, tax, consulting and transactions |
| 4 | KPMG | New York, NY | ~$15.90 billion | Audit, tax, risk and financial advisory |
| 5 | RSM US | Chicago, IL | ~$4.20 billion | Accounting, tax and advisory for middle-market businesses |
| 6 | Baker Tilly | Chicago, IL | ~$3.67 billion | Audit, tax and advisory |
| 7 | BDO USA | Chicago, IL | ~$3.02 billion | Assurance, tax and advisory |
| 8 | CBIZ | Cleveland, OH / New York, NY | ~$2.81 billion | Professional and financial advisory services |
| 9 | Grant Thornton | Chicago, IL | ~$2.46 billion | Assurance, tax and business advisory |
| 10 | Forvis Mazars | Springfield, MO / New York, NY | ~$2.32 billion | Accounting and advisory services |
1. Deloitte
Net Revenue: ~$35.69 billion
Headquarters: New York, NY
Main Business: Audit, tax, consulting and financial advisory
Deloitte is the largest firm on this list by the revenue figures provided. It is also one of the four firms commonly grouped as the Big Four accounting firms.
Its work covers several areas of business. Audit and tax remain major parts of the firm, while consulting and financial advisory make up other important areas.
Deloitte works with large companies as well as organisations across different industries. Its size allows the firm to offer several types of professional services under one name.
The firm has one of the broadest service ranges among the accounting firms listed here. That is one reason it sits at the top of the US ranking by revenue in the source figures.
Unique Offerings
● Audit and assurance
● Tax services
● Consulting
● Financial advisory
● Services for large businesses and organisations
Official website: Deloitte
2. PwC
Net Revenue: ~$25.57 billion
Headquarters: New York, NY
Main Business: Assurance, tax and advisory services
PwC, short for PricewaterhouseCoopers, is another member of the Big Four. Its US business provides assurance, tax and advisory services to companies across different sectors.
The firm has a large corporate client base and is known for working with Fortune 500 companies. Its services cover both financial reporting and wider business matters.
Assurance work is a major part of the firm’s business. PwC also provides tax services and advisory work for companies dealing with financial and business decisions.
Its position near the top of the list reflects the size of its US operations. The firm has a much larger revenue figure than the mid-tier firms that follow the Big Four.
Unique Offerings
● Assurance services
● Tax services
● Business advisory
● Work with Fortune 500 companies
● Global professional services
Official website: PwC
3. Ernst & Young (EY)
Net Revenue: ~$24.74 billion
Headquarters: New York, NY
Main Business: Assurance, tax, consulting, strategy and transactions
Ernst & Young, better known as EY, is the third Big Four firm on this list. Its US operations cover assurance, tax, consulting and strategy and transactions.
The firm’s work goes beyond traditional accounting. Businesses can use EY for assurance and tax work as well as consulting and support related to major transactions.
Strategy and transactions are a notable part of its service offering. This gives the firm a role in areas that involve business changes, investments and other major financial decisions.
EY’s revenue figure places it just behind PwC among the firms listed here. Like the other Big Four firms, it operates across a wide range of business services.
Unique Offerings
● Assurance
● Tax services
● Consulting
● Strategy and transactions
● Business advisory services
Official website: EY
4. KPMG
Net Revenue: ~$15.90 billion
Headquarters: New York, NY
Main Business: Audit, tax, risk and financial advisory
KPMG is the fourth member of the Big Four. Its US operations include audit, tax, risk and financial advisory services.
The firm has a strong presence in regulated industries. Its work in these sectors includes financial and risk-related services alongside its accounting and tax work.
KPMG also works with businesses on financial matters and advisory projects. The range of services allows it to handle both traditional accounting work and broader business requirements.
With approximately $15.90 billion in net revenue, KPMG is the fourth-largest firm in this list. There is a clear gap between its revenue and that of the next firm, RSM US.
Unique Offerings
● Audit and assurance
● Tax services
● Risk advisory
● Financial advisory
● Services for regulated industries
Official website: KPMG
5. RSM US
Net Revenue: ~$4.20 billion
Headquarters: Chicago, IL
Main Business: Accounting, tax and advisory services
RSM US is the largest firm on this list outside the Big Four. It focuses mainly on middle-market businesses.
The firm’s services cover accounting, tax and advisory work. Its focus is different from the large global firms that dominate the first four positions.
Middle-market companies often need several professional services but may not have the same requirements as the largest multinational corporations. RSM US has built its business around this part of the market.
Its approximately $4.20 billion in net revenue puts it well ahead of the other mid-tier firms in this list.
Unique Offerings
● Middle-market accounting services
● Tax services
● Business advisory
● Financial services
● Focus on middle-market companies
Official website: RSM US
6. Baker Tilly
Net Revenue: ~$3.67 billion
Headquarters: Chicago, IL
Main Business: Audit, tax and advisory services
Baker Tilly provides audit, tax and advisory services in the US. The firm works with growing middle-market businesses as well as larger enterprises.
Its services cover several areas of financial and business work. Companies can use the firm for audit and tax requirements as well as advisory projects.
Baker Tilly’s position in the market puts it among the larger accounting firms outside the Big Four. Its revenue of about $3.67 billion places it sixth in the list.
The firm also offers specialised services for businesses with different financial and operational needs.
Unique Offerings
● Audit services
● Tax services
● Advisory services
● Middle-market business support
● Services for larger enterprises
Official website: Baker Tilly
7. BDO USA
Net Revenue: ~$3.02 billion
Headquarters: Chicago, IL
Main Business: Assurance, tax and advisory services
BDO USA is a major national accounting firm with offices across the country. Its work includes assurance, tax and advisory services.
The firm serves businesses that need support with financial reporting, tax matters and other professional services. Its national office network gives it a presence in several major US markets.
BDO USA is smaller than Baker Tilly and RSM US by the revenue figures used in this list, but it remains one of the larger accounting firms in the country.
Its approximately $3.02 billion in net revenue places it seventh among the firms covered here.
Unique Offerings
● Assurance services
● Tax services
● Business advisory
● National office network
● Services for businesses across different industries
Official website: BDO USA
8. CBIZ
Net Revenue: ~$2.81 billion
Headquarters: Cleveland, OH / New York, NY
Main Business: Professional services and financial advisory
CBIZ provides professional and financial advisory services to businesses and other organisations. It differs from the traditional accounting firms at the top of the list because its services extend across several professional areas.
The company also works closely with attest firms such as MHM. This allows related professional services to be provided alongside accounting and financial work.
CBIZ has revenue of approximately $2.81 billion based on the figures used for this list. That places it eighth among the 10 firms.
Its business model covers more than standard accounting work, with financial advisory forming an important part of its offering.
Unique Offerings
● Professional services
● Financial advisory
● Business services
● Work with attest firms
● Services for businesses and organisations
Official website: CBIZ
9. Grant Thornton
Net Revenue: ~$2.46 billion
Headquarters: Chicago, IL
Main Business: Assurance, tax and business advisory
Grant Thornton is one of the larger accounting firms in the USA outside the Big Four. It provides assurance, tax and business advisory services.
The firm is often seen as an alternative to the Big Four for companies looking for a large accounting and advisory provider. Its services cover both financial reporting and wider business needs.
Grant Thornton has approximately $2.46 billion in net revenue according to the figures used here. That puts it ninth in the list.
The firm focuses on providing accounting and advisory services while maintaining a more focused position than the four largest firms.
Unique Offerings
● Assurance services
● Tax services
● Business advisory
● Accounting services
● Alternative to the Big Four
Official website: Grant Thornton
10. Forvis Mazars
Net Revenue: ~$2.32 billion
Headquarters: Springfield, MO / New York, NY
Main Business: Accounting and advisory services
Forvis Mazars is the result of a major cross-border combination. The firm operates in the US while also offering accounting and business services through its wider international network.
Its work covers accounting and advisory requirements for businesses. The firm’s structure gives it both a US presence and an international reach.
With approximately $2.32 billion in net revenue, Forvis Mazars ranks tenth in this list. It is one of the newer names among the major accounting firms following its formation through the combination.
The firm provides another option for companies that need accounting and advisory services at both national and international levels.
Unique Offerings
● Accounting services
● Advisory services
● US operations
● International reach
● Cross-border professional services
Official website: Forvis Mazars
Why the Accounting Industry Is Important in the USA
The Big Four Have a Large Share of the Market
Deloitte, PwC, EY and KPMG occupy the first four positions in the list by the revenue figures provided. Their services cover audit, tax, consulting, risk and financial advisory work.
Their size also means that they can work with some of the largest companies and organisations in the country.
Middle-Market Firms Have a Different Role
RSM US, Baker Tilly and BDO USA are examples of large accounting firms that sit outside the Big Four. RSM US has a particularly strong focus on middle-market businesses.
These firms give companies another choice when they need audit, tax or advisory services without necessarily working with one of the four largest firms.
Accounting Firms Do More Than Audit
Traditional accounting remains an important part of the industry, but the services offered by these firms have become much broader.
Tax, consulting, risk management, financial advisory and business services now make up major parts of the work carried out by many large accounting firms.
The Industry Includes Different Types of Firms
The firms in this list are not identical. Deloitte, PwC, EY and KPMG operate at a very large scale. RSM US focuses strongly on the middle market, while CBIZ has a broader professional services model.
That difference matters when businesses choose an accounting firm. The right firm depends on the size of the business, the type of work required and whether services are needed only in the US or across several countries.
Conclusion
The US accounting industry is led by the Big Four, with Deloitte ranking first by the revenue figures used in this list. PwC, EY and KPMG follow, while RSM US, Baker Tilly and BDO USA make up the next group of large firms.
The remaining firms, including CBIZ, Grant Thornton and Forvis Mazars, also have sizeable operations and provide accounting, tax and advisory services. Together, these firms show how broad the US accounting market has become, from traditional audit work to financial and business advisory services.
FAQs
Which is the largest accounting firm in the USA?
Deloitte is the largest firm in this list based on the net revenue figures provided, at approximately $35.69 billion.
What are the Big Four accounting firms?
The Big Four are Deloitte, PwC, Ernst & Young (EY) and KPMG.
Which accounting firm focuses on middle-market businesses?
RSM US is particularly focused on middle-market businesses and is the largest non-Big Four firm in this list by the revenue figures provided.
Is PwC bigger than EY in the USA?
Based on the figures used in this list, PwC has approximately $25.57 billion in net revenue, compared with about $24.74 billion for EY.
What services do large accounting firms provide?
Large accounting firms provide services such as audit, tax, assurance, consulting, risk management, financial advisory and other business services.
Which accounting firms are based in Chicago?
RSM US, Baker Tilly, BDO USA and Grant Thornton are listed with Chicago, Illinois, as their headquarters.
Is Grant Thornton a Big Four firm?
No. Grant Thornton is a large accounting firm outside the Big Four. It provides assurance, tax and business advisory services.
What is Forvis Mazars?
Forvis Mazars is an accounting and advisory firm formed through a major cross-border combination. It has US operations and provides accounting and advisory services.
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