The consulting field guide
What are the Big 4
consulting firms?
Deloitte, PwC, EY and KPMG. Four global professional services networks spanning audit, tax and advisory—including consulting.
Free practice requires an account. This guide and the example below are open to everyone.
01 / Know the landscape
Four firms. A useful starting point.
The Big 4 are often discussed as consulting firms, but consulting is one part of a much broader business. Each network has local member firms and multiple service lines. The role and team matter as much as the name.
Deloitte
Audit and assurance, tax, strategy and transactions, technology and business transformation.
EY
Assurance, consulting, tax, and strategy and transactions through EY-Parthenon.
KPMG
Audit and assurance, tax and advisory, including technology, risk and business improvement.
Service summaries checked against each firm’s official website on October 3, 2026. The links above go to those sources.
02 / Understand the work
What do the Big 4 actually do?
Their portfolios combine financial reporting, tax, specialist advisory and business change. Names and organizational structures vary by firm and country.
- Audit & assurance
- Work on financial reporting and assurance over information and processes. This is distinct from preparing for a consulting case interview.
- Tax
- Tax compliance, planning and specialist advice. Qualifications and local rules can be central to the role.
- Advisory & consulting
- Work can include transactions, risk, strategy, operations and technology transformation. Read the specific practice’s description to understand its focus.
For consulting applicants
Put the research into practice.
Work on structuring a problem, explaining your reasoning and business math.
03 / Compare thoughtfully
How are the Big 4 different from MBB?
MBB means McKinsey, Boston Consulting Group and Bain. They are commonly associated with management and strategy consulting. The Big 4 combine consulting with large audit, assurance, tax and advisory portfolios.
This is a starting distinction, not a rule about every project or role. The Big 4 also offer strategy work; MBB firms also work on implementation and transformation. Compare the practice and job, not just the category.
Read the Big 4 vs MBB comparisonWhich differences matter when choosing?
A global league table cannot tell you what your local team will be like. Start with these questions:
- The work: What problems does this practice solve, and what would you do in your first year?
- The team: Which office, clients and colleagues would you work with?
- The path: What training, qualifications, feedback and progression does the role involve?
- The process: Which assessments and interviews does this exact vacancy require?
04 / Make your next move
Preparing to apply to the Big 4
Choose a service line and location before building a preparation plan. Audit, tax and consulting applications can call for different knowledge, qualifications and assessment formats.
- Read the actual vacancy. Check eligibility, deadlines, responsibilities and the local recruitment process.
- Match your evidence to the role. Prepare examples of problem solving, teamwork and communicating a recommendation.
- Prepare for the stated assessment. If the role includes case interviews, practice structure, business math and clear reasoning. Do not assume every Big 4 application uses cases.
For broader planning, see the consulting application deadlines guide and our case interview preparation guide. Confirm dates on the relevant employer’s listing.
Where Caselane fits
If you are preparing for consulting interviews, use Caselane to work on structured problem solving and business math, then practice explaining your approach. Start with the example on this page and continue into the practice platform when you are ready.
You can also explore ResumeLane for your CV and PeopleLane for networking. Access depends on your account; these tools are separate from the open guide.
The questions people ask
Big 4 FAQs
Who are the Big 4 consulting firms?
Deloitte, PwC, EY and KPMG. The Big 4 label refers to professional services networks whose work spans audit, tax and advisory, including consulting.
Is McKinsey a Big 4 firm?
No. McKinsey is usually grouped with Boston Consulting Group and Bain as MBB. Deloitte, PwC, EY and KPMG make up the Big 4.
Are the Big 4 only accounting firms?
No. Audit and tax are central to their businesses, but their service portfolios also include consulting, technology, risk, strategy and transactions.
What is the difference between advisory and consulting?
The labels vary by firm and country. Advisory can include transactions, risk and specialist work; consulting often includes business and technology transformation. Read the specific team's service description and job listing rather than relying on the label alone.
Do the Big 4 do strategy?
Yes. Their service portfolios include strategy and transactions alongside broader professional services. PwC lists strategy through Strategy&, and EY lists strategy and transactions through EY-Parthenon.
Which Big 4 firm should I apply to?
Compare the actual role, office, team, work and recruitment process. A consulting role and an audit role at the same firm can require very different preparation. Global brand or size alone is not enough to choose.
What does career progression look like?
Titles and paths vary by country and service line. Entry roles can lead to senior, manager and leadership positions. Check the local team's progression expectations, qualifications and responsibilities rather than treating one ladder as universal.
From understanding to doing
Make your thinking the advantage.
You know the four firms. If consulting is your next move, start building the skills to discuss a business problem clearly.
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