Author: Taylor Warfield, Former Bain Manager and interviewer

Last Updated: March 16, 2026

Written case interviews are a special type of consulting interview used by BCG, Bain, Deloitte, and PwC during final round interviews. You will receive 20 to 40 pages of data, work independently to analyze the information, create presentation slides, and then present your recommendation to the interviewer.

 

According to Glassdoor data from 2025, roughly 40% of final round candidates at BCG and Bain will face a written case. In my experience coaching over 30,000 candidates, it is one of the most underestimated parts of the consulting interview process.

 

This guide covers everything you need to know: the exact format at each firm, a 10-step process for solving written cases, time allocation plans, slide strategies, common mistakes, and preparation tips.

 

But first, a quick heads up:

 

McKinsey, BCG, Bain, and other top firms accept less than 1% of applicants every year. If you want to triple your chances of landing interviews and 8x your chances of passing them, watch my free 40-minute training.

 

What is a Written Case Interview?

 

A written case interview is a variant of the traditional case interview where you work independently rather than collaborating with the interviewer. You receive a packet of data, analyze it on your own, build presentation slides, and then present your findings.

 

At the start of the interview, you will be handed 20 to 40 pages of graphs and charts, tables, interview notes, and other text. The interviewer will leave the room.

 

You will then have 1 to 2 hours to read the material, create 3 to 5 slides, and prepare a recommendation. When time is up, the interviewer returns and you present your work for 20 to 40 minutes, including follow-up questions.

 

Written cases are always given during second or final round interviews. For firms that use them, you cannot receive an offer unless you pass.

 

Which Consulting Firms Use Written Case Interviews?

 

The four consulting firms most commonly associated with written case interviews are BCG, Bain, Deloitte, and PwC. Each firm has its own format. Knowing the differences will help you prepare for the specific version you will face.

 

What is the BCG Written Case Interview Format?

 

The BCG written case is the longest and most open-ended version. Here is the typical format:

 

• BCG provides approximately 40 PowerPoint slides describing the client situation, including charts, graphs, tables, and text from industry reports

 

• You receive 3 to 4 key questions from a simulated partner email asking you to investigate and answer specific business issues

 

• You have 2 hours to review the slides and create your presentation

 

• BCG provides blank slides, so you decide how many slides to make and how to design them

 

• You are allowed to use a calculator

 

• You then have approximately 40 minutes to present and discuss your recommendations with the interviewer

 

Based on Glassdoor reports from 2025, BCG uses written cases in their U.S., U.K., Russia, Sweden, Netherlands, and South Africa offices. Not every BCG office uses them, so ask your recruiter if you are unsure.

 

What is the Bain Written Case Interview Format?

 

The Bain written case is shorter and more structured than BCG's version. Here is what to expect:

 

• Bain provides 20 to 30 PowerPoint slides describing the client situation

 

• You have 55 to 60 minutes to review the material and prepare your slides

 

• Bain provides 4 to 6 pre-filled slide templates with titles, partially completed charts, or blank spaces you must fill in by hand

 

• You are NOT allowed to use a calculator

 

• You are NOT allowed to write on the information slides (only on the provided templates)

 

• You then have approximately 40 minutes to present and answer follow-up questions

 

According to Bain's own careers page, written cases are most common in their European, Asian, and Greater China offices. They are less common in North America. Bain uses written cases in final round interviews only.

 

Do Deloitte and PwC Use Written Case Interviews?

 

Yes. Both Deloitte and PwC (Strategy&) use written case interviews in certain offices. The formats vary more widely at these firms compared to BCG and Bain.

 

Some Deloitte offices provide a written case 2 to 3 days before the interview, giving you significantly more preparation time. Others follow a format similar to BCG with a timed, in-person session. Always confirm the specific format with your recruiter.

 

How Do Written Case Interviews Differ From Verbal Case Interviews?

 

Written case interviews and traditional verbal case interviews test similar skills, but the format is quite different. Having coached thousands of candidates through both types, I find that the biggest adjustment is shifting from a collaborative conversation to independent analysis. Here is a side-by-side comparison.

 

Dimension	Verbal Case Interview	Written Case Interview
Format	Collaborative conversation with interviewer	Work independently, then present
Duration	30 to 45 minutes total	1 to 2 hours prep + 40 minutes presentation
Data volume	Interviewer shares data one piece at a time	20 to 40 pages given all at once
Output	Verbal discussion and recommendation	Handwritten or typed slides and presentation
Feedback	Real-time hints and nudges from interviewer	No guidance until presentation
Primary skill tested	Structured thinking and verbal communication	Data synthesis, slide-making, and storytelling
Interview round	First and second round	Second or final round only

 

The biggest difference is that you are on your own during a written case. In a verbal case, the interviewer will redirect you if you go off track. In a written case, there is no safety net.

 

What Skills Do Written Case Interviews Assess?

 

Written case interviews test four core skills that directly mirror what consultants do every day. Understanding what interviewers are evaluating helps you focus your preparation.

 

1. Structured problem solving

 

Can you take a complex, ambiguous business problem and break it into clear, logical components? Interviewers want to see that you do not jump straight into the data. Instead, you should create a framework first and then use the data to answer each part of that framework.

 

2. Data analysis and interpretation

 

Can you sift through 20 to 40 pages of information and quickly identify what matters? According to a 2024 BCG recruiting survey, data interpretation is the number one reason candidates fail written cases. Most of the information in the packet is noise. Your job is to separate signal from noise.

 

3. Slide-making and written communication

 

Can you turn your analysis into slides that are clear, concise, and tell a compelling story? Each slide should have one key message communicated through a descriptive title. If you want a structured way to master these and other case skills quickly, my case interview course walks you through each one with practice cases and drills.

 

4. Presentation and defense

 

Can you present your work confidently and defend your recommendation under pressure? The interviewer will challenge your assumptions and push back on your conclusions. This is not a sign you are wrong. It is a test of whether you can articulate your reasoning clearly.

 

How Do You Solve a Written Case Interview in 10 Steps?

 

Follow this 10-step process to solve any written case interview efficiently. In my experience at Bain, this is the same approach that top-performing consultants use when preparing client presentations under tight deadlines.

 

Step 1: Read the instructions and understand the business problem

 

Before touching the data, read the case prompt at least twice. What is the primary question you are being asked to answer? Answering the wrong question is the fastest way to fail a written case. If you received a list of 3 to 4 key questions, note them down.

 

Step 2: Quickly scan the entire packet

 

Flip through all 20 to 40 pages in about 5 minutes. Do not read in detail. Your goal is to understand what types of data are available: market data, financial statements, customer survey results, competitor analysis, and so on. Note which slides look relevant to the key questions.

 

Step 3: Build a framework

 

Create a case interview framework just as you would in a verbal case. Select 3 to 4 broad areas that you need to investigate to answer the business question. If the case gave you specific questions, those questions may form most or all of your framework.

 

Step 4: Map data to your framework

 

Now that you know what questions to answer, match the available data to each framework area. Write the slide numbers next to each framework bucket so you know exactly where to find the information you need. This saves enormous time later.

 

Step 5: Analyze the most important areas first

 

Start with the highest-priority questions. Read the relevant slides in detail, perform calculations, and write a 1 to 2 sentence takeaway for each area. Having coached thousands of candidates, I have seen that roughly 80% of your answer will come from about 20% of the slides.

 

Step 6: Decide on a recommendation

 

Review your key takeaways and decide what recommendation they support. Not every data point will agree. Some findings may contradict your recommendation, and that is expected. Choose the recommendation that the strongest evidence supports and acknowledge trade-offs.

 

Step 7: Outline your presentation structure

 

Before writing any slides, decide on the structure. A proven format is:

 

• Slide 1: Recommendation and the 3 supporting reasons

 

• Slides 2 to 4: One slide per reason with the supporting data

 

• Slide 5: Risks, trade-offs, or next steps

 

This structure mirrors how real consulting presentations are delivered: recommendation first, evidence second.

 

Step 8: Fill in your slides

 

Write descriptive titles for each slide that communicate the key message. If the interviewer only reads your slide titles in order, they should understand your entire argument. Use charts, numbers, and evidence from the packet. Keep each slide focused on one message.

 

Step 9: Review for errors

 

Check your math. Double-check that your slide titles tell a coherent story from first to last. Look for any inconsistencies between your data and your recommendation. A single math error can undermine your credibility with the interviewer.

 

Step 10: Prepare for follow-up questions

 

Use any remaining time to think about what the interviewer might challenge. What assumptions did you make? What data did you not use? What would you investigate if you had more time? According to candidates who have been through written cases, roughly 50% of the presentation time is spent answering follow-up questions.

 

How Should You Allocate Your Time in a Written Case Interview?

 

Time management is one of the biggest challenges in written case interviews. Based on patterns I have seen from coaching candidates through hundreds of written cases, here are the recommended time splits for both the 1-hour and 2-hour formats.

 

Activity	55-60 Min (Bain)	2 Hours (BCG)
Read instructions and scan packet	5 minutes	10 minutes
Build framework and map data	5 minutes	10 minutes
Analyze data and take notes	25 minutes	50 minutes
Decide recommendation and outline slides	5 minutes	10 minutes
Fill in slides	15 minutes	30 minutes
Review and prepare for questions	5 minutes	10 minutes

 

A common mistake is spending too long reading and not leaving enough time for slides. Set a hard deadline for yourself: no matter what, start building your slides by the halfway point.

 

What Should Your Written Case Presentation Slides Look Like?

 

Your slides do not need to be beautiful. They need to be clear, structured, and easy to follow. Interviewers at BCG and Bain have told me that they would rather see a messy slide with a sharp insight than a polished slide with a weak point.

 

How Should You Write Slide Titles?

 

The slide title is the single most important element on each slide. A good title communicates the key message, not just the topic.

 

Weak Title	Strong Title
Market Analysis	The US market is growing at 12% annually, making it the top priority
Financial Overview	Entering Market X would generate $15M in profit within 3 years
Conclusion	We recommend entering Market X based on strong growth, low competition, and high margins

 

Test your titles by reading them in order. If someone could understand your entire argument just from the titles, you have done it right.

 

How Many Slides Should You Create?

 

For a 55-minute Bain case, aim for 3 to 5 slides. For a 2-hour BCG case, aim for 4 to 6 slides. Quality matters far more than quantity. Each slide should contain exactly one key message supported by evidence.

 

If you find yourself putting multiple charts or messages on a single slide, either split it into two slides or cut the less important information. Cluttered slides are one of the top reasons candidates score poorly on the written communication dimension.

 

What Are the Most Common Written Case Interview Mistakes?

 

After coaching over 30,000 candidates, I see the same written case mistakes appear again and again. Avoiding these will put you ahead of most other candidates.

 

Mistake 1: Solving the wrong problem

 

This is the number one reason candidates fail. They get absorbed in an interesting data point and forget the actual question. Always refer back to the original prompt before building your slides.

 

Mistake 2: Trying to use all the data

 

Written cases deliberately include more information than you need. In a typical 40-page BCG packet, roughly 50% of the slides are distractors. One of the key skills being tested is your ability to identify what is relevant and ignore what is not.

 

Mistake 3: Running out of time

 

Candidates spend too long reading and analyzing, then rush through slide creation. A common rule from former Bain interviewers: if you have not started your slides by the halfway mark, you are behind.

 

Mistake 4: Using generic slide titles

 

Titles like "Analysis" or "Summary" tell the interviewer nothing. Every title should be a complete sentence that states the insight. Roughly 70% of your score on slide quality comes from the strength of your titles.

 

Mistake 5: Making unsupported claims

 

Every statement in your slides should be backed by data from the packet. If you cannot point to a specific chart, table, or data point that supports your claim, do not include it. Interviewers will ask where your numbers came from.

 

Mistake 6: Forgetting next steps

 

Including a "next steps" slide takes only 1 to 2 minutes but demonstrates initiative and ownership. List 2 to 3 things you would investigate if you had more time. This is how real consultants end every client presentation.

 

How Do You Prepare for a Written Case Interview?

 

Written cases are harder to practice than verbal cases because there are fewer publicly available practice materials. However, there are several effective preparation strategies.

 

Practice with free cases from firm websites

 

BCG offers a practice written case called Chateau Boomerang on their careers website. Bain provides written case tips and example materials on their interview prep page. Deloitte has multiple practice cases including Footloose and Recreation Unlimited. Start with these official resources because they are the most realistic.

 

Summarize consulting reports into slides

 

Download 2 to 3 industry reports published by BCG or Bain (they are free on their websites). Set a timer for 60 minutes and summarize each report into 3 to 5 slides with descriptive titles. This exercise builds the exact muscles you need: fast reading, synthesis, and slide-making.

 

Practice mental math

 

Bain does not allow calculators, so you must be comfortable doing multiplication, division, and percentage calculations by hand. Aim to solve basic calculations in under 30 seconds. Practice 10 to 15 math problems per day in the weeks leading up to your interview.

 

Master verbal case interviews first

 

Written cases build on the same core skills as verbal cases: structured thinking, frameworks, data interpretation, and synthesis. If you are not yet comfortable with verbal cases, start there. If you want personalized feedback on your cases, my 1-on-1 coaching helps you improve roughly 5x faster than solo practice.

 

Practice under timed conditions

 

Always practice with a timer. Without time pressure, written cases are relatively straightforward. The challenge is completing everything to a high standard within 55 to 120 minutes. Do at least 3 to 5 timed practice runs before your real interview.

 

What Are the Best Written Case Interview Tips?

 

These 10 tips come from my experience as a Bain interviewer and from coaching thousands of candidates through written cases.

 

• Tip 1: Read the prompt at least twice before touching the data. Understanding the exact question is more important than reading every slide.

• Tip 2: Build your framework before reading the data in detail. This prevents you from getting lost in irrelevant information.

• Tip 3: Set time checkpoints. Know exactly when you should finish analyzing, start building slides, and begin reviewing. Stick to these deadlines.

• Tip 4: Answer the key questions first. If the case provides 3 to 4 specific questions, answer those before exploring anything else.

• Tip 5: Lead with your recommendation. Your first slide should state your recommendation and the 3 reasons that support it. This is how real consultants present to clients.

• Tip 6: Write action-oriented slide titles. Each title should be a complete sentence communicating the insight, not just a topic label.

• Tip 7: Keep one message per slide. Cluttered slides with multiple charts confuse the interviewer and dilute your argument.

• Tip 8: Support every claim with data. The interviewer will ask "where did this number come from?" for anything unsupported.

• Tip 9: Include a next steps slide. It takes 1 to 2 minutes and shows the initiative that interviewers are looking for.

• Tip 10: Practice your presentation out loud. If time allows, walk through your slides verbally before the interviewer returns. This helps you catch gaps in your logic and feel more confident.

 

Frequently Asked Questions

 

Can You Fail a Written Case Interview and Still Get an Offer?

 

No. At firms that use written case interviews, the written case counts as much as a verbal case interview. If you fail the written case, you will not receive an offer regardless of how well you performed on the other interviews.

 

Are Written Case Interviews Harder Than Verbal Case Interviews?

 

Most candidates find written cases harder because there is no real-time feedback from the interviewer. In a verbal case, the interviewer gives you hints if you go off track. In a written case, you are entirely on your own during the preparation phase. The upside is that you have more time and can work at your own pace.

 

Do All BCG and Bain Offices Use Written Case Interviews?

 

No. Written cases are more common in certain geographies. BCG uses them most frequently in the U.S., U.K., Russia, Sweden, Netherlands, and South Africa. Bain uses them primarily in Europe, Asia, and Greater China. If you are interviewing with either firm, ask your recruiter whether your final round will include a written case.

 

Can You Use a Calculator During a Written Case Interview?

 

It depends on the firm. BCG allows calculators during their written case. Bain does not allow calculators. If you are interviewing with Bain, make sure you practice mental math extensively before your interview.

 

How Many Slides Should You Create for a Written Case Interview?

 

For a 55-minute Bain case, aim for 3 to 5 slides. For a 2-hour BCG case, aim for 4 to 6 slides. The exact number depends on how many key questions you need to answer and how much data supports each point. Quality always matters more than quantity.

 

Where Can You Find Written Case Interview Practice Materials?

 

BCG offers the Chateau Boomerang practice written case on their careers website. Bain provides written case tips on their interview prep page. Deloitte has several practice cases on their website. You can also practice by summarizing BCG or Bain industry reports into 3 to 5 slides under timed conditions.

 

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