Author: Taylor Warfield, Former Bain Manager and interviewer

Last Updated: July 7, 2026

 

Written case interviews are a special type of consulting interview used by BCG, Bain, Deloitte, and PwC where you analyze 20 to 40 pages of data on your own, build 3 to 5 slides, and present your recommendation to the interviewer. This guide walks you through the exact format at each firm, a 10-step solving process, time allocation plans, slide strategies, common mistakes, and the most effective ways to prepare.

 

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Key Takeaways

 

A written case interview asks you to independently analyze a packet of 20 to 40 pages of data, build 3 to 5 presentation slides, and defend your recommendation in front of an interviewer.

 

• BCG gives you about 40 pages, 2 hours, blank slides, and a calculator

 

• Bain gives you 20 to 30 pages, roughly an hour, pre-filled slide templates, and no calculator

 

• Your slide titles matter more than anything else on your slides, so write each one as a complete sentence that states the insight

 

• Most of the packet is deliberately irrelevant, and finding the few slides that matter is the core skill being tested

 

• Start building your slides by the halfway point no matter what, since running out of time is the most common way to fail

 

What Changed in 2026?

 

Bain retired its dedicated written case page and folded interview guidance into a single hiring process hub, so format details now come mostly from recruiters and recent candidate reports. This update refreshes each firm's format against those current sources, removes outdated statistics, and adds new guidance on slide storylines, BCG's no-writing rule, and what to bring on interview day.

 

What Is a Written Case Interview?

 

A written case interview is a variant of the traditional case interview where you work independently instead of collaborating with the interviewer. You receive a packet of 20 to 40 pages of data, analyze it alone for 1 to 2 hours, create 3 to 5 presentation slides, and then present your recommendation.

 

At the start of the interview, you are handed a thick packet of graphs and charts, tables, interview notes, and text from industry reports. The interviewer then leaves the room and you work on your own.

 

When time is up, the interviewer returns and you present your work for 20 to 40 minutes, including follow-up questions. Expect the discussion to be interactive: the interviewer will push back on your conclusions the same way a client would.

 

 

Written cases appear during second or final round interviews, never the first round. For firms that use them, the written case counts as much as any other interview, so you cannot receive an offer unless you pass it.

 

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 runs its own version, and knowing the differences tells you exactly what to practice.

 

What is the BCG written case interview format?

 

The BCG written case is the longest and most open-ended version. If you are preparing for a BCG case interview final round, here is the typical format:

 

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

 

• The first page is a simulated email from a BCG partner asking you to answer 3 to 4 key questions about the client's business

 

• You have 2 hours to review the material and build your presentation, which is the same time limit BCG uses in the practice written case published on its careers site

 

• BCG provides blank slides, so you decide how many slides to create and how to design them, with 3 to 5 slides being the expectation

 

• You are allowed to use a calculator, but you are typically not allowed to write on the information documents since BCG reuses them across candidates

 

• You then have approximately 40 minutes to present and discuss your recommendation, split roughly evenly between presenting and answering questions

 

Based on candidate reports, BCG has used written cases most often in its US, UK, Netherlands, Sweden, 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. If you have a Bain case interview final round coming up, here is what to expect:

 

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

 

• You have 55 to 90 minutes to review the material and prepare your slides, with the exact time varying by office

 

• Bain provides 3 to 5 pre-filled slide templates with titles, partially completed charts, or blank spaces you fill in by hand

 

• You are NOT allowed to use a calculator, so every calculation happens on paper or in your head

 

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

 

• You then have 30 to 40 minutes to present and answer follow-up questions

 

The pre-filled templates mean you do not have to invent the overall storyline yourself. Your job is to find the data that supports each slide title and complete the analysis accurately.

 

Based on candidate reports, Bain has used written cases primarily in its European, Asian, and Greater China offices, and 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. The Deloitte case interview process in certain offices includes a written component, and the formats vary more widely than at BCG and Bain.

 

Some Deloitte offices provide the written case materials 2 to 3 days before the interview, giving you far more preparation time. Others run a timed, in-person session similar to BCG's format, and some final rounds also include a group case interview on top of the written exercise.

 

At PwC, the written case shows up most often in the Strategy& case interview process, where candidates receive a data pack and present their recommendation to the interviewer. Always confirm the specific format with your recruiter before final round.

 

How Do Written Case Interviews Differ From Verbal Case Interviews?

 

Written case interviews test similar skills to verbal cases, but the experience is completely different. Having interviewed candidates at Bain and coached hundreds more 1-on-1, I find the biggest adjustment is shifting from a collaborative conversation to fully independent analysis.

 

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 plus 20 to 40 minutes presenting
Data volume	Interviewer shares data one piece at a time	20 to 40 pages given all at once
Output	Verbal discussion and recommendation	Handwritten slides and a presentation
Feedback	Real-time hints and nudges from interviewer	No guidance until you present
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 redirects you if you go off track. In a written case, there is no safety net until you are standing in front of your finished slides.

 

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 evaluate tells you where to focus your preparation.

 

• Structured problem solving: can you break a complex, ambiguous business problem into clear, logical components before touching the data. Interviewers want to see a framework first and data second, never the reverse

 

• Data analysis and interpretation: can you sift through 20 to 40 pages and quickly identify what matters. Most of the packet is deliberately noise, and your job is to separate signal from that noise

 

• Slide-making and written communication: can you turn your analysis into slides that are clear, concise, and tell a story. Each slide should carry exactly one key message communicated through a descriptive title

 

• Presentation and defense: can you present confidently and defend your recommendation under pressure. Pushback from the interviewer is not a sign you are wrong, it is a test of how you handle challenge

 

These are the same skills tested in verbal cases, just packaged differently. If you want a fast, structured way to build them, my case interview course takes you through each one with practice cases and drills in as little as 7 days.

 

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 mirrors exactly how top-performing consultants prepare client presentations under tight deadlines.

 

1. Read the instructions and understand the business problem: read the case prompt at least twice before touching the data. Answering the wrong question is the fastest way to fail, so write down the 3 to 4 key questions if you received them
   
   
2. Quickly scan the entire packet: flip through all the pages in about 5 minutes without reading in detail. Your goal is to learn what types of data exist and which slides look relevant to the key questions
   
   
3. Build a framework: create a case interview framework just as you would in a verbal case. Select 3 to 4 broad areas you need to investigate, or use the key questions themselves as your framework
   
   
4. Map data to your framework: write the packet page numbers next to each framework bucket so you know exactly where to find the information you need. This one habit saves more time than anything else
   
   
5. Analyze the most important areas first: form a case interview hypothesis, then read the relevant pages in detail and write a 1 to 2 sentence takeaway for each area. Roughly 80% of your answer will come from about 20% of the pages
   
   
6. Decide on a recommendation: review your takeaways and choose the recommendation the strongest evidence supports. Some data points will contradict it, and that is expected, so acknowledge the trade-offs
   
   
7. Outline your presentation structure: put your recommendation and its 3 supporting reasons on slide 1, one reason with its data on each of slides 2 to 4, and risks or next steps on slide 5. Recommendation first, evidence second
   
   
8. Fill in your slides: write a descriptive title on each slide that states the key message, then support it with charts, numbers, and evidence from the packet. Keep each slide focused on one message
   
   
9. Review for errors: check your math and confirm your slide titles tell a coherent story from first to last. A single math error can undermine your credibility with the interviewer
   
   
10. Prepare for follow-up questions: use any remaining time to anticipate what the interviewer will challenge. Think through your assumptions, the data you did not use, and what you would investigate with more time

 

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

 

Time management is the single biggest challenge in written case interviews. From coaching candidates through both the 1-hour and 2-hour formats, here are the time splits I recommend.

 

Activity	55 to 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

 

The most common failure pattern is spending too long reading and leaving no 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, and in my experience interviewers would rather see a messy slide with a sharp insight than a polished slide with a weak point.

 

Bring your own supplies on interview day where allowed. A ruler for clean chart lines and 2 to 3 highlighters for marking key data make handwritten slides noticeably faster to produce and easier to read.

 

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 12% annually, making it the top priority
Financial Overview	Entering the US would generate $15M in profit within 3 years
Conclusion	We recommend entering the US based on strong growth, low competition, and high margins

 

Test your titles by reading them in order, because together they should tell the complete story. Here is an illustrative example of a 5-slide storyline where every number is a made-up placeholder:

 

1. We recommend entering the US market, which would add $15M in annual profit within 3 years
   
   
2. The US market is growing 12% per year while the client's domestic market is flat
   
   
3. The client's premium brands already outsell the top 3 competitors in comparable markets
   
   
4. Entry requires a $5M upfront investment and breaks even early in year 2
   
   
5. Next steps: validate distribution partners and test pricing in a 3-month pilot

 

If the interviewer could understand your entire argument from the titles alone, you have done it right. This is exactly how real consulting decks are written.

 

How many slides should you create?

 

For a Bain written case, complete the 3 to 5 pre-filled templates you are given. For a BCG written case, aim for 3 to 5 slides, which is the number BCG's own practice written case asks for.

 

Quality matters far more than quantity, and each slide should contain exactly one key message supported by evidence. If you find yourself putting multiple messages on a single slide, either split it in two or cut the weaker point.

 

What Are the Most Common Written Case Interview Mistakes?

 

Having coached hundreds of candidates 1-on-1 and reviewed countless practice slides, I see the same written case mistakes appear again and again. Avoiding these puts 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 drift away from the actual question. Always check your slides against the original prompt before finalizing anything.

 

Mistake #2: Trying to use all the data

 

Written cases deliberately include more information than you need, and a large share of the pages are distractors. One of the key skills being tested is your ability to ignore what does not matter.

 

Mistake #3: Running out of time

 

Candidates spend too long reading and analyzing, then rush through slide creation. 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. In my experience reviewing candidate slides, the strength of your titles drives more of your score on written communication than any other element. Every title should be a complete sentence that states the insight.

 

Mistake #5: Making unsupported claims

 

Every statement on your slides should trace back to a specific chart, table, or data point in the packet. Interviewers will ask "where did this number come from?" for anything unsupported. If you cannot point to the source, cut the claim.

 

Mistake #6: Forgetting risks and next steps

 

Adding a short risks and next steps slide takes only 1 to 2 minutes but demonstrates initiative and ownership. List 2 to 3 things you would investigate with more time. This is how real consultants end every client presentation, and very few candidates do it.

 

How Do You Prepare for a Written Case Interview?

 

Written cases are harder to practice than verbal cases because there are fewer publicly available materials. The good news is that five preparation strategies cover everything you need.

 

Practice with free official cases from firm websites

 

BCG publishes a full practice written case on its case interview preparation page, complete with a 2-hour time limit and sample candidate answers. Bain shares practice cases and interview guidance on its hiring process pages, and Deloitte offers multiple free cases through the prep tools on its case interview tips page. 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, which 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 handle multiplication, division, and percentage calculations by hand. Build your case interview mental math speed until basic calculations take you under 30 seconds. Practice 10 to 15 math problems per day in the weeks before 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. Work through plenty of case interview examples before layering on written case practice. If you want expert feedback on your written case slides and presentation delivery, my 1-on-1 coaching gives you a former Bain interviewer's perspective on exactly where you are losing points.

 

Practice under timed conditions

 

Always practice with a timer, because without time pressure written cases are relatively straightforward. The real challenge is completing everything to a high standard within 55 to 120 minutes. You can also use MBA consulting casebooks as raw material by giving yourself 90 minutes to turn a full case into slides, and you should do at least 3 to 5 timed runs before the real interview.

 

What Are the Best Written Case Interview Tips?

 

These 10 tips come from my time as a Bain interviewer and from coaching hundreds of candidates through written cases 1-on-1.

 

Tip #1: Read the prompt at least twice before touching the data

 

Understanding the exact question is more important than reading every page. Everything you do afterward depends on getting this right.

 

Tip #2: Build your framework before reading the data in detail

 

A framework gives every page you read a purpose. Without one, you will absorb 40 pages of information with no way to organize it.

 

Tip #3: Set time checkpoints and stick to them

 

Know exactly when you should finish analyzing, start building slides, and begin reviewing. Treat each checkpoint as a hard deadline, not a suggestion.

 

Tip #4: Answer the key questions first

 

If the case provides 3 to 4 specific questions, answer those before exploring anything else. Extra insight only counts after the core questions are nailed.

 

Tip #5: Lead with your recommendation

 

Your first slide should state your recommendation and the reasons that support it. This is how real consultants present to clients, because senior audiences want the answer before the analysis.

 

Tip #6: Write action-oriented slide titles

 

Each title should be a complete sentence communicating the insight, not a topic label. "Revenue fell 8% due to share loss in the largest segment" beats "Revenue Analysis" every time.

 

Tip #7: Keep one message per slide

 

Cluttered slides with multiple charts confuse the interviewer and dilute your argument. When in doubt, cut.

 

Tip #8: Support every claim with data

 

The interviewer will probe anything that looks unsupported. Note the packet page number next to each claim so you can answer instantly when challenged.

 

Tip #9: Include a risks and next steps slide

 

It takes 1 to 2 minutes and signals the ownership mindset interviewers want to see. Naming the risks makes your recommendation stronger, not weaker.

 

Tip #10: Practice your presentation out loud

 

If time allows, walk through your slides verbally before the interviewer returns. Speaking your argument out loud catches gaps in logic that reading silently misses.

 

Master these tips and the written case interview shifts from the scariest part of your final round to a genuine advantage over other candidates. The single most important action you can take today is to complete one full practice case under real timed conditions.

 

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 in your 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 nudges you back on track if you drift. In a written case, you are entirely on your own during the preparation phase. The upside is that you can work at your own pace.

 

Do all BCG and Bain offices use written case interviews?

 

No. Based on candidate reports, BCG has used written cases most often in offices in the US, UK, Netherlands, Sweden, and South Africa, while Bain has used them primarily in Europe, Asia, and Greater China. Ask your recruiter whether your final round will include one.

 

Can you use a calculator during a written case interview?

 

It depends on the firm. BCG allows calculators during its written case. Bain does not allow calculators, so you must be comfortable doing multiplication, division, and percentage calculations by hand. If you are interviewing with Bain, practice mental math extensively before your interview.

 

How many slides should you create for a written case interview?

 

For a 55-minute Bain case, complete the 3 to 5 pre-filled slides you are given. For a 2-hour BCG case, aim for 3 to 5 slides, which is the number BCG asks for in its own practice written case. Quality always matters more than quantity.

 

Where can you find written case interview practice materials?

 

BCG publishes a practice written case on its careers site, Bain shares interview prep resources on its hiring process pages, and Deloitte offers free practice cases through its case interview prep tool. You can also practice by summarizing BCG or Bain industry reports into 3 to 5 slides under timed conditions.

 

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