The BCG Online Case (Casey): format, rules and how to prepare in 2026

What is the BCG Online Case, and is it the same thing as Casey?

Candidates use "BCG online case" for every digital step BCG sends them, which muddles the search results. The one people mean when they say Casey is a chatbot-led business case: a written situation, then questions that arrive one at a time, then a short video answer. BCG's own 2025 candidate guide calls it the Online Case Assessment and describes it as "conducted by our chatbot", taken from home on a personal computer. Coaching sites also call it the Online Case Experience, a phrase that turns up in the guide's glossary too.

We read that guide on 29 September 2026. It is dated 2025, it is distributed by BCG's assessment vendor, HireQuotient, and it sits on the vendor's file storage rather than on careers.bcg.com. Some coaching sites attribute it to BCG's Mexico office, so treat every figure below as what BCG's own document said for at least one office in 2025. BCG's public interview-process page, which we also read, lists a skills interview, a case interview and a team interview and says nothing detailed about the online steps.

Which BCG online test will you be sent?

The name in your invitation is the only reliable guide. BCG does not run one identical screen everywhere, and the pages we could open show at least two different designs before you meet an interviewer. Click through the four below; the first two are the ones most candidates end up comparing.

Coaching sites also report regional mixes, for example a short numerical test for UK applicants and a logical-reasoning test in the Nordics. We list them only as reports, because none of the BCG pages we opened confirm them, and because a test that changes every year is best confirmed by the person who emails you the link.

What does a Casey session look like, minute by minute?

Everything in the timeline below is from BCG's 2025 candidate guide unless it says otherwise. The design choice that shapes behaviour most is the last line of the middle step: the clock keeps running whether you are reading, calculating or typing, and the interface will not let you return to anything you have submitted.

Thirty-five minutes across 8 to 10 questions averages between 3.5 and 4.4 minutes each (35 divided by 10, and 35 divided by 8), but the average is not what you will experience. A structuring question can take ninety seconds and a two-step calculation on an exhibit can take five, so the useful habit is to know within the first thirty seconds of a question which kind it is and how long you are allowed to spend on it. Plan to block an hour, because the guide's own figure of about 40 minutes leaves nothing for a slow start or a reboot.

Coaching sites put the quantitative share of the questions well above half; one puts it near 70 percent. We could not verify a figure and would not plan around one. What is safe to say is that arithmetic on an exhibit is the biggest single thing in the session, which is why the next question is worth attempting before you read on.

The second thing to read before you start is the guide's glossary, which is the closest thing to a rulebook for the arithmetic. It says that unless a question states otherwise, profit means operating profit (gross profit less operating expenses), cost of goods sold is treated as variable, and operating expenses are treated as fixed. Our quiz followed those defaults: the €1.5m is fixed and the cost of goods and shipping vary with orders. The glossary also defines market share, substitutes, complements and expected profit, with a worked example (a 60 percent chance of making $100,000 and a 40 percent chance of losing $50,000 gives an expected profit of $40,000). If those definitions are not automatic, the case maths guide covers them.

Can you use a calculator, Excel or outside help on Casey?

A calculator, yes, by BCG's own document. The 2025 guide says a webcam-enabled laptop and a calculator are both required for the test, and tells you not to take it on a mobile phone. That is the strongest primary statement we found, and it is more permissive than the cognitive test BCG Switzerland and Germany describe, where tools are ruled out. Coaching sites agree that a calculator is normally fine for Casey, and an earlier version of this page was too vague on the point.

The guide does not say whether a calculator app on your phone counts, and it does not say anything about spreadsheets. We would use a physical calculator on the desk, in view of the camera, and ask the recruiter if you want to do anything else. A Glassdoor forum post whose title we could see, but not its replies, says a consultant told the poster that switching to an Excel tab has not been allowed "since this year". That is second-hand and unconfirmed. It is also the direction BCG's own proctoring line points, which lists window switching as something the system watches for.

Outside help follows from the same reasoning. The guide names multiple faces in the video, tab switching, copy-paste and window switching as the behaviours the recording is there to detect, so a second person in the room and a chat assistant in another window both appear on that list. We found no BCG statement about AI tools for this test in particular, and the rules change fast enough that we will not guess. Our position is plain: do not use outside help. The screen exists to find out whether you can do the job, and an offer won on a borrowed answer gets tested hard in the live rounds.

Does BCG detect tab switching, and what happens if it does?

What BCG says is short. The guide's proctoring note reads, in substance, that the system records your video (only after taking your consent) to detect and protect against errors and to prevent fraud and suspicious activities like multiple faces in the video, tab switching, copy-paste and window switching. It does not say what counts as a flag, who reviews one, or what follows.

What candidates and coaches report is more reassuring and less reliable. In a PrepLounge thread started on 1 February 2026, a candidate asked whether tab switching is detected and whether recruiters can see the contents of other tabs. Replies from coaches on the platform, an ex-Bain and an ex-BCG coach among them, said the platform logs switches with timestamps, that a single quick switch away and back does not trigger the kind of severe flag that leads to automatic rejection, that recruiters do not see what was in the other tab, and that suspicious behaviour would raise questions before it ended a candidacy. No BCG representative replied in the thread, and coaches are not the people who configure the platform.

Our reading, and it is only a reading: assume everything is logged, assume a human sees a flag that trips a threshold, and do not plan around the leniency. If you are playing it straight, the realistic risk is the accidental flag, so shut down everything that can pull focus. Quit chat apps, turn off notifications, close every tab except the assessment, and pause anything that syncs. If something does trip it by accident, tell your recruiter afterwards in a sentence. A short note from you reads better than an unexplained line in a dashboard, though that is judgement, not a BCG rule.

How is Casey scored, and what is the pass mark?

Two things are in BCG's guide, and the rest is not. The guide says you will not learn your score, as with a live case, and it says scoring varies by question type and each question may carry a different weight. That is a change from what we could say in an earlier version of this page, which treated weighting as unknowable: we now know BCG says questions are not worth the same.

Everything else is unpublished, including partial credit on numeric answers, whether wrong answers cost you anything, who or what marks the video, and the pass mark. Coaching sites say no negative marking has been reported, so answer every question, which you must do anyway because you cannot skip. Some sites quote a share of candidates who advance, usually somewhere in the 20 to 30 percent range. That is unofficial and unsourced, and we would ignore it, because a funnel number cannot tell you which question to spend an extra minute on.

What the weighting does tell you is that the questions with the most steps are probably worth more, which is an argument for spending your slack minutes there rather than perfecting the four-line answer at the start. Treat that as a working assumption, not knowledge. For what BCG-style marking looks like in a live case, how case interviews are scored publishes ours.

How do you handle the recorded video recommendation?

The video is the one part of Casey that behaves like a live case, because you are speaking to a person you cannot see. BCG's guide gives you one minute to read the question and prepare, then recording starts on its own for one minute, and you get one attempt. Sixty seconds at a comfortable pace is about 150 words, so the recommendation has no room for a warm-up. We split the minute 10 seconds for the answer, 20 for each of two reasons, and 10 for a risk and a next step (10, 20, 20 and 10 make 60).

Try it before reading ours. The case below is invented by us for practice and is not a real Casey question. It uses the same online store as the break-even quiz, so the arithmetic is already half done.

Here is what that sounds like at speed. It runs to about 150 words, which is what one minute holds, and it is deliberately unpolished.

Notice that every number spoken came from something established earlier, that the risk is one sentence and that the close is a decision rule, not a summary. Deliver it looking at the camera lens rather than your own preview, and use the preparation minute to write three or four words per point on paper, not sentences. This is the skill our rubric calls synthesis, and the anchors below are the ones we mark against in live cases. Casey is not scored on our rubric, so read them as a target for the habit, not a promise about your grade.

Is Casey different from a live case, and does live practice help?

It tests overlapping skills through a harder-to-forgive mechanism. In a live case, thinking aloud earns credit: the interviewer hears the false start, hears the correction and can nudge you back if you misread the question. In the chatbot, only the final answer exists. There is no clarifying question to ask, no hint between questions and no interviewer's face to read, so a structure held in your head is invisible and a number typed without units may be marked as wrong.

Some candidates find that easier because the pressure is a countdown instead of a person. Candidates who think best by talking often find it harder, because only the destination is recorded, not the route. Neither group is right about the format; they are describing themselves. We would still argue that the underlying habits carry across, which is why the same three things fix most Casey mistakes: read the question before touching the answer box, commit to a conclusion in the first sentence, and put units on every number.

We do not simulate Casey. We have no copy of BCG's interface, its exhibits or its marking, and anyone offering a faithful simulation is guessing at the same things we are. What we run is the live case that comes after it, which is where most of the hiring decision sits, so it is a sensible thing to keep practising in parallel.

All our coaches are AI personas built by ex-MBB interviewers, and they are not a substitute for a human partner who can tell you your delivery is dull. The BCG case interview covers the live rounds, and interviewer-led versus candidate-led cases explains why the chatbot, which sets the order and the questions, behaves like the interviewer-led kind.

How should you prepare in the last two weeks, and where can you practise for free?

Start with BCG's own material, since it is free and it is the format you will face. The 2025 guide says the practice case in your invitation email is meant to get you comfortable with the chatbot interface, and that it does not stand in for the real test. Beyond that, BCG's case interview preparation page points to a case library for self-study and to OneDay@BCG, a free job simulation. Coaching sites sell their own Casey-style simulators, and their quality varies; try a free sample before paying.

The written questions are where people under-prepare, because they feel small. A short structuring answer is a real test of whether you can commit to a view with a reason, so try one before you read ours.

Check that last figure, since it is the kind of arithmetic a fill-in question tests. If contribution falls from €12 to €10, break-even moves from 125,000 to 150,000, which is 25,000 more (1,500,000 divided by 10 is 150,000). A €2 slip on €12 is a sixth of the margin, and it moves break-even by a fifth, which is why unit costs deserve suspicion.

What should the day itself look like?

Most preventable losses on Casey are logistical. BCG's guide asks for a webcam laptop and a calculator, a stable connection with at least 512 kbps upload, and no mobile phone. It prefers Chrome, recommends disabling any VPN and ad blockers, and suggests an incognito window. It says the test must be taken in one sitting because the timer keeps running even if you are logged out.

Interruptions are the part you can rehearse in your head. The guide is specific: if the session is interrupted, you can log back in with the same invitation email and password and land at the same place, but the time has kept running. Try the scenario before you check the answer.

If the fault is on BCG's side, for example the video service refusing to start, the guide says a slightly unstable connection can make it take up to 30 seconds to connect, and suggests closing other apps that use the camera, rebooting, changing browser or trying another computer. Message your recruiter as soon as the session is over, with the time and what you saw.

What comes after Casey?

For client-facing roles, BCG's public interview-process page lists a skills interview, a case interview and a team interview after the application. Coaching sites report a live round of about two case interviews of roughly 45 minutes each and a final round with partners, but BCG's Germany and Austria page shows the sequence differs by office, with two case interviews in a second round and short conversations alongside. Ask your recruiter what your office does, and the consulting recruiting timeline sets it in context.

Use the time between Casey and the first live round for what Casey cannot test: structuring out loud, leading a conversation, and answering the fit questions. The BCG case interview guide covers the firm's live format, and preparing for a case interview gives the sequence we would follow. If you are also applying elsewhere, the online steps at McKinsey Solve and Bain's assessment are different animals, and the preparation does not transfer.