The most useful first step for a Big Four interview is to identify the work you are applying to do. Deloitte, PwC, EY and KPMG recruit across many teams. A strategy case, a technology scenario and a written business exercise can require different preparation even when the same firm name appears on the invitation.
Build your preparation around the role, level and task. Then strengthen the common skills: understanding the objective, organising evidence, working through numbers and explaining a decision.
I would spend ten minutes getting that map right before spending ten hours on cases chosen only because someone labelled them “Big Four”.
Turn the invitation into a practice brief
Record four things in plain language:
| Detail | Why it changes preparation |
|---|---|
| Country and team | Identifies the relevant recruiting guidance and type of client work. |
| Entry level or experienced role | Helps establish how much specialist knowledge and delivery judgment to prepare. |
| Task and output | Distinguishes a conversation, written note, presentation, group exercise or technical task. |
| Timing and permitted materials | Determines how you should rehearse. |
If the invitation says “case study” without explaining the output, ask whether you will discuss a scenario live, review a pack beforehand or produce something written. That is a focused process question the recruiter can answer without revealing the assessment.
Ask your recruiter which tasks, timing and permitted tools to expect when the missing detail affects your preparation.
Follow the relevant firm’s preparation route
Start with the official source, then use the corresponding guide for a worked rehearsal.
| Application | Official starting point | What to practise next |
|---|---|---|
| Deloitte consulting or a related scenario role | Case and scenario guidance | Connect a proposed change to a feasible business outcome in the Deloitte guide. |
| PwC Advisory or consulting | US Advisory case preparation | Explain the business value, assumptions and trade-offs behind your recommendation. |
| EY Consulting | US candidate interview guide | Trace a proposed change from user behaviour to business results. |
| KPMG consulting or advisory | KPMG India recruiting overview | Work through costs, constraints and the evidence needed to make a decision. |
The process varies by country and applicant group. For example, PwC UK's graduate Advisory and Consulting route includes a virtual assessment centre and a later business assessment. Prepare for the route attached to your application.
Rehearse what you must produce
Consider three illustrative invitations.
A live case discussion: practise hearing a prompt, clarifying the objective, proposing an approach and using information as it arrives. Ask your partner to change an assumption so you must update your view.
A short pack followed by a presentation: practise selecting the decisive exhibits and developing a recommendation before polishing the slides. Keep the calculation behind each claim available for questions.
A group business exercise: practise contributing evidence, comparing options and integrating other people’s information. Your task includes helping the group think clearly, not merely presenting your individual answer.
The same business problem can support all three rehearsals, but the performance task differs. For a written case, rehearse selecting evidence and delivering a short presentation. For a group case, practise moving the discussion forward while testing others’ reasoning constructively.
Quick Structuring Drill
A 12-shop bakery chain can fund one growth idea this year. You have five minutes to present your recommendation to the owners.
| Option | Extra weekly sales | Contribution margin | Extra weekly running cost |
|---|---|---|---|
| Delivery | £12,000 | 30% | £2,400 |
| Evening opening | £8,000 | 60% | £3,000 |
Which headline should open your recommendation to the owners?
Make your analysis specific to the client
Here is a simple original prompt: a council wants to reduce the time residents wait for a permit. A generic answer might recommend digitisation, staff training and improved communication.
A useful approach first locates the delay. Are applications waiting because information is missing, because specialist review capacity is limited or because completed decisions are released in batches?
Each cause suggests different work. A clearer form can reduce missing information. It cannot by itself create specialist capacity. Hiring more reviewers will not remove a delay caused by a weekly release schedule.
Explain the mechanism before recommending a solution. Then test the cost, feasibility and effect on service quality. This habit transfers across strategy, operations and technology cases.
Prepare experience at the right level
Keep examples of your own decisions, teamwork and learning ready. An early-career applicant can use university, volunteering, employment or personal projects. An experienced applicant should be able to explain the complexity of their work and the trade-offs they managed.
In both cases, move beyond “we delivered the project”. Explain what you personally noticed, chose and changed. If an outcome fell short, describe what you learned and what you did with that lesson.
Do not borrow a firm’s sample scenario as a personal story. Use it to understand the reasoning expected, then discuss experiences you actually lived through.
Quick Answer Repair Drill
You advised a food wholesaler to close one of its two depots to cut costs. The client has now shared peak-day volume data.
- Peak orders, both depots
- 10,000 per day
- Remaining depot capacity
- 7,000 orders per day
- Annual saving from closure
- £1.2 million
A colleague drafts: ‘The saving is unchanged, so close as planned.’ What is the main flaw?
Build the next week around your weakest task
Start with one representative attempt. Review where the work breaks down: defining the objective, setting up the equation, selecting evidence or explaining the recommendation.
Choose a short exercise that repairs that behaviour, then retest it in the actual format. If you can calculate accurately alone but lose the thread while speaking, another silent worksheet is unlikely to solve the whole problem.
Keep a practice log that records the observed difficulty, correction and fresh test. The purpose of firm research is to choose better practice. Once you have the right task, spend most of your time doing it.
Frequently asked questions
Working out which interview you face
Do Deloitte, PwC, EY and KPMG all use the same case interview?
You should not assume they do. Each firm recruits across many teams, so a strategy case, a technology scenario and a written business exercise can call for different preparation even under the same firm name. Identify the team, level and task first. Then strengthen common skills such as clarifying the objective and organising evidence.
What should I note from my interview invitation before I start practising?
Note, in plain language, the details that change your preparation. The country and team point to the relevant recruiting guidance and type of client work. Whether the role is entry level or experienced shapes how much specialist knowledge and delivery judgement to prepare. The task and output tell you whether to expect a conversation, written note, presentation, group exercise or something technical.
Where do I find out how a particular Big Four firm runs its case interviews?
Start with the firm’s official guidance, then use a matching guide for a worked rehearsal. For a Deloitte consulting or scenario role, start with its case and scenario guidance. Then practise linking a proposed change to a feasible business outcome. For PwC Advisory or consulting, the guide names PwC’s US Advisory case preparation as the official starting point.
Is a Strategy&, EY-Parthenon or Monitor Deloitte interview the same as one with the wider firm?
Not necessarily, so follow the instructions for the specific team named in the vacancy. The broader network name does not tell you the format. Even within one strategy or transactions brand, different roles may ask different questions. The actual work you would be doing is therefore the best guide to what to rehearse.
How should I prepare differently for a general strategy role compared with a specialist one?
For a general strategy role, practise working through unfamiliar commercial decisions. For a specialist role, such as valuation or data work, build your preparation around what that job involves. This matters because one strategy brand can contain both kinds of role, and rehearsing only broad business cases may leave gaps before a specialist task.
Rehearsing the task you will actually face
How do I practise for a live case discussion with an interviewer?
Rehearse the full sequence aloud. Hear the prompt, clarify the objective, propose an approach and use new information as it arrives. Ask a practice partner to change an assumption partway through so you get used to updating your view. That tests how well you adapt, which a pre-prepared answer cannot show.
What if I am given a short pack of materials and then asked to present?
Select the decisive exhibits and form a recommendation before you polish any slides. Keep the calculation behind each claim to hand so you can explain it if challenged. A polished deck built on the wrong evidence is harder to rescue than a plain one with a clear, supported answer.
How can I stop my case answers sounding generic?
Locate the cause of the problem before recommending fixes. Take a council that wants shorter waits for permits. Rather than proposing digitisation, training and better communication, ask whether applications stall because information is missing, specialist review capacity is limited or decisions are released in batches. Each cause points to different work. A clearer form only helps if missing information is the issue.
Experience questions and your practice plan
I am early in my career. What examples can I use in a Big Four interview?
Draw on university, volunteering, employment or personal projects. What matters is showing your own decisions, teamwork and learning rather than the group’s result. Instead of saying “we delivered the project”, explain what you personally noticed, what you chose to do and what changed because of it.
What should experienced applicants emphasise in their examples?
Be ready to explain the complexity of your work and the trade-offs you managed. A clear personal contribution is the foundation at any level. An experienced applicant should also show the judgement behind difficult choices and explain how those choices shaped what was delivered.
Should I talk about a project that did not go well?
Yes, if you can describe what you learned. An outcome that fell short can still be a strong example when you explain your own role clearly and show what you would now do differently. Avoid glossing over the result or blaming the team.
How should I plan my next week of case practice?
Build it around your weakest task. Make one representative attempt, then review where it breaks down: defining the objective, setting up the equation, selecting evidence or explaining the recommendation. Choose a short exercise that repairs that behaviour and retest it in the actual interview format. Keep a practice log so you can see whether the fix holds.
I calculate accurately on my own but lose the thread when I speak. What should I do?
Practise calculating aloud rather than doing more silent worksheets. Your weakness is combining maths with explanation, so another written drill is unlikely to solve the whole problem. Rehearse talking through each step, ideally with a partner, then retest in the same format your interview uses.