Author: Taylor Warfield, Former Bain Manager and interviewer

Last Updated: September 6, 2026

 

The EY-Parthenon first round interview is typically one or two back-to-back case interviews of 25 to 45 minutes each, run by consultants or managers, where you solve a business problem with heavy math and very little hand-holding. This article covers exactly what happens in each first round format, what interviewers score you on, a full worked case example, and the prep plan that gets candidates into the final round.

 

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Key Takeaways

 

Passing the EY-Parthenon first round comes down to solving one or two candidate-led cases quickly and accurately, because most first round formats spend little or no time on your background.

 

• First round is usually one or two case interviews of 25 to 45 minutes each with consultants or managers

 

• EY's UK Strategy route runs two 25-minute cases back to back with no biographical questions at all

 

• Profitability, market entry, market sizing, and private equity diligence cases dominate the first round

 

• Case data often arrives as a printed or on-screen slide packet instead of verbal exhibits

 

• Glassdoor rates the interview 3.3 out of 5 in difficulty, with about 31 days from application to offer in 2026

 

• Speed and accuracy on math separate the candidates who advance from the ones who do not

 

What Is the EY-Parthenon First Round Interview?

 

The EY-Parthenon first round interview is the firm's first live evaluation of your problem solving, held after your application and online assessment clear. It consists of one or two candidate-led case interviews with consultants or managers, each running 25 to 45 minutes. You receive a business prompt, build your own structure, work through the quantitative analysis, and deliver a recommendation.

 

The phrase "first round" causes real confusion at this firm, and getting it wrong costs candidates their prep time. Some candidates count the 30-minute recruiter screen as round one, which makes the case round sound like round two. EY's own materials treat the case stage as the first round of interviews, and that is the definition used throughout this article.

 

Where EY-Parthenon differs from most Big Four interviews is difficulty. The firm sits inside EY but hires against strategy consulting standards, so the EY-Parthenon case interview looks far more like a Bain or BCG case than a generic advisory interview. Candidates who prepare for a standard Big Four conversation get cut in round one.

 

How Many Interview Rounds Does EY-Parthenon Have?

 

EY-Parthenon runs two to three interview rounds depending on your track, region, and level. The table below maps the full sequence so you know exactly where the first round sits.

 

Stage	What happens	Who runs it	Typical length
Application	Resume, cover letter, and short written motivation questions	Recruiting team	N/A
Online assessment	Numerical reasoning, rank order and written tasks, plus recorded video answers	Automated	45 to 60 min
Recruiter screen	Resume walkthrough, motivation, and logistics. Skipped in some offices and tracks	HR recruiter	30 min
First round	One or two candidate-led cases, sometimes with a short fit opener	Consultants and managers	25 to 45 min each
Final round	Two longer cases plus a senior leadership interview, often with a group or written case	Directors and partners	3 to 4 hours

 

Two tracks publish their first round format openly. EY states on its UK early careers page that Strategy candidates face two 25-minute case interviews led by consultants, conducted back to back, with no biographical questions whatsoever. Operational Diligence and Software Strategy Group candidates go through a first interview stage that EY describes as mainly case study based, followed by a final round with a partner.

 

The US process is looser. EY's US Consultant Program page says candidates should expect a mix of behavioral and case-based interviews with multiple EY-Parthenon professionals, without publishing a fixed round structure. US Strategy recruiting currently runs through nine offices: Atlanta, Boston, Chicago, Dallas, Houston, Los Angeles, New York, San Francisco, and Tysons.

 

Before any of this, your application has to survive a resume screen that eliminates most candidates. A strong EY-Parthenon resume does more for your odds than any amount of case practice, because case practice only matters once somebody invites you in.

 

Glassdoor's 2026 breakdown of how 727 EY-Parthenon candidates landed their interview is worth knowing: 46% applied online, 34% came through campus recruiting, and 12% used an employee referral. If your school is on EY-Parthenon's target list, campus events are the single best use of your time. If it is not, an EY-Parthenon referral is the channel most candidates never bother to work.

 

What Happens in an EY-Parthenon First Round Case Interview?

 

You get a prompt, you drive the analysis, and the interviewer answers the questions you ask. EY-Parthenon uses a candidate-led format, which means nobody hands you the next step. If you stop talking, the silence sits there, and that silence is part of the evaluation.

 

The candidate-led structure is the single biggest adjustment for people coming from McKinsey-style prep. In an interviewee-led case interview, you choose which branch of your structure to investigate, when to ask for data, and when the analysis is finished. Waiting to be prompted reads as passivity.

 

How long is each first round case interview?

 

Twenty-five to forty-five minutes, and the shorter end is more common than candidates expect. The UK Strategy round uses two 25-minute cases with roughly 5 to 10 minutes between them. A candidate who interviewed at EY's Canary Wharf office in November 2025 described exactly that setup: one case with a manager, a short break, then a second case with someone a level more senior.

 

Twenty-five minutes is not much time. You have to clarify the objective, structure, analyze, and recommend inside a window that leaves no room for a slow start. Budget roughly 3 minutes to structure, 15 to analyze, and 3 to synthesize.

 

What case types show up most in the first round?

 

Private equity flavored cases dominate, because commercial due diligence is the core of what EY-Parthenon sells. A PE fund is looking at a target, and you have to judge whether the market and the business support the investment thesis. The table below covers what actually appears.

 

Case type	What you are asked to do	How often it appears in round one
Commercial due diligence	Judge whether a PE fund should acquire a target based on market growth and competitive position	Very common
Profitability	Diagnose why margins are falling and quantify the fix	Very common
Market entry	Decide whether a client should enter a new geography, segment, or product line	Common
Market sizing	Estimate the size of a market from the ground up, usually inside a larger case	Common as a sub-question
Sector-specific	Work through a live industry topic drawn from an interviewer's real engagement	Occasional

 

The sector-specific cases catch people off guard. That same London candidate got a case on data center infrastructure for a private equity investor and a second on hydrogen transportation economics, both drawn from engagements the interviewers had actually run. Real deals become real cases at this firm.

 

Boston summer associate candidates in the 2025 cycle reported a single profitability case in round one, with the harder material saved for the super day. That pattern is common in US campus recruiting: one clean case to filter, then a much longer final round.

 

Expect a market sizing question buried inside a larger case rather than as a standalone prompt. The estimate is rarely the point. Interviewers want to see whether your assumptions are defensible and whether you can carry a number through to a decision.

 

How is the case information given to you?

 

Often as a slide packet rather than verbally, which changes how you should prepare. Candidates describe receiving a printed deck or an on-screen document containing all the exhibits, then working through questions that reference specific pages. One Software Strategy Group candidate in London was handed a docket with short calculation questions followed by case questions built on the same data.

 

This format rewards a specific skill: reading a dense exhibit fast and pulling out the one number that matters. Practicing with case interview graphs and charts is more useful here than practicing verbal cases, because the bottleneck is interpretation speed, not listening. Get comfortable scanning a table, naming the trend in one sentence, and moving on.

 

Does the EY-Parthenon First Round Include Behavioral Questions?

 

Sometimes, and the answer depends entirely on your track. EY explicitly states that its UK Strategy first round includes no biographical questions, so candidates spend the full 50 minutes on cases. US and experienced hire candidates far more often report 5 to 10 minutes of fit questions before the case starts.

 

When fit questions do appear in round one, they are short and predictable. "Tell me about yourself," "why consulting," and "why EY-Parthenon" cover the large majority of what gets asked at this stage. The serious behavioral evaluation is saved for the partner interview in the final round.

 

Do not treat the brevity as permission to wing it. A weak answer to why EY-Parthenon signals that you applied to every strategy firm without thinking, and that impression colors how an interviewer reads the rest of your performance. Preparing for the EY-Parthenon behavioral interview takes a few hours and protects the case work you spent weeks on.

 

If you want structured answers to the fit questions fast, my fit interview course covers 98% of consulting behavioral questions in a few hours.

 

What Do EY-Parthenon Interviewers Look For in the First Round?

 

Five things, and they are scored independently. Having interviewed and recruited candidates at Bain, I can tell you that first round scorecards are blunt instruments. An interviewer with 25 minutes is not building a nuanced portrait of you, they are checking boxes.

 

• Structure: the ability to break a problem into buckets that are genuinely distinct and cover the whole question

 

• Quantitative accuracy: getting the arithmetic right the first time, out loud, without a calculator

 

• Business judgment: knowing which number actually drives the decision and which one is a distraction

 

• Communication: stating your answer first and your reasoning second, in language a client would follow

 

• Coachability: taking a hint or a correction and adjusting instead of defending a wrong path

 

Quantitative accuracy is where most rejections happen. EY-Parthenon cases lean harder on math than the average strategy case because diligence work is fundamentally about numbers: growth rates, margins, multiples, and payback periods. Drilling case interview mental math until you can multiply three-digit numbers cleanly under pressure is the highest-return prep you can do.

 

Structure matters, but not the way most candidates think. Interviewers are not looking for an elegant tree, they are checking whether your buckets actually let you answer the question. A messy structure that drives to the right insight beats a beautiful one that goes nowhere.

 

What Does an EY-Parthenon First Round Case Look Like?

 

Here's an example built in the commercial due diligence style that dominates round one. All figures are illustrative.

 

Interviewer: Our client is a private equity fund considering a $600 million acquisition of a US chain of 200 veterinary clinics. Their thesis requires growing revenue by 50% over five years. Is that achievable?

 

You: Before I structure this, I'd like to confirm two things. First, is the 50% target on revenue rather than EBITDA? Second, is the fund open to acquiring new clinics, or is the thesis built on organic growth only?

 

Interviewer: Revenue, and both levers are available. The chain currently generates $2.5 million of revenue per clinic at a 12% EBITDA margin.

 

Start by sizing the base and the target. At 200 clinics and $2.5 million each, current revenue is $500 million, and the 50% target means reaching $750 million. That is $250 million of new revenue to find.

 

Check the price while you're there. A 12% margin on $500 million gives $60 million of EBITDA, so a $600 million purchase price implies a 10x multiple. Naming that unprompted signals commercial instinct.

 

Now split the $250 million across the two levers. If same-clinic revenue grows 3% annually, five years of compounding gives roughly 16% cumulative growth, or about $80 million on the existing base. That leaves $170 million to come from new clinics.

 

At $2.5 million per clinic, $170 million requires 68 new locations, or roughly 14 per year. On a 200-clinic base, that is about 7% annual footprint expansion.

 

Recommendation: the target is achievable but demanding. It needs 3% same-clinic growth every year plus 14 new clinic openings annually for five straight years. I'd want to verify two things before committing: whether the chain has historically opened at that pace, and whether the local markets can absorb 68 new clinics without cannibalizing existing ones.

 

Notice what that answer does. It commits to a position, quantifies both levers, and names the specific risks that would change the conclusion. That is the shape of a strong first round close.

 

How Do You Prepare for the EY-Parthenon First Round?

 

Four weeks is enough if you use it well. The sequence below front-loads math and structure, then shifts to full timed cases in the EY-Parthenon format.

 

1. Week 1, build the fundamentals: learn how to structure a case, then drill mental math for 20 minutes daily until three-digit multiplication and percentage changes are automatic
   
   
2. Week 2, master the core case types: work through 8 to 10 cases covering profitability, market entry, and market sizing, focusing on getting the math right rather than finishing fast
   
   
3. Week 3, go private equity heavy: practice commercial due diligence cases, learn to read dense exhibits quickly, and get comfortable with growth rates, EBITDA multiples, and payback periods
   
   
4. Week 4, simulate the real thing: run two 25-minute cases back to back with a partner, under time, using printed exhibits instead of verbal data

 

Week 4 is the step candidates skip, and it costs them. Solving one relaxed 45-minute case is a different exercise from solving two 25-minute cases with a 5-minute gap. Running mock case interviews in the exact format you'll face is what turns competence into performance.

 

UK Strategy candidates get an advantage worth using. EY matches interview candidates with a mentor from the business who shares a preparation pack containing example case studies and tips for the interview. Ask that mentor what the cases actually look like, because they have seen them.

 

If you're short on time, my case interview course compresses this into a system that gets you to a top 10% candidate level in about 7 days.

 

What Are the Best EY-Parthenon First Round Interview Tips?

 

These are the adjustments that matter specifically at EY-Parthenon, not generic case advice.

 

Tip #1: Prepare for a 25-minute clock, not a 45-minute one

 

Most case practice runs long, which trains a pace that will sink you here. Set a 25-minute timer for every practice case in your final week and force yourself to synthesize before it goes off.

 

Tip #2: Learn the private equity vocabulary before you walk in

 

You should be able to define EBITDA, an entry multiple, and a payback period without hesitating. These terms appear constantly in diligence cases, and fumbling one signals that you have not researched what this firm actually does.

 

Tip #3: Ask for the exhibit packet upfront

 

If the interviewer mentions a deck or a document, ask whether you can look through it before you start structuring. Knowing what data exists shapes a much better structure than guessing.

 

Tip #4: Say your assumptions out loud, every time

 

Silent math is unscoreable math. When you assume 3% growth or a 12% margin, say the number and say why, so the interviewer can follow your logic even if your arithmetic slips.

 

Tip #5: Answer first, then explain

 

Consultants are trained to lead with the conclusion, and interviewers score you on whether you already work that way. Open every synthesis with your recommendation, then give the two or three reasons behind it.

 

Tip #6: Reset completely between the two cases

 

The 5 to 10 minute gap between back-to-back cases exists for a reason. Interviewers do not compare notes mid-round, so a shaky first case does not doom the second unless you carry the anxiety into it.

 

Tip #7: Have two sharp questions ready

 

Even a case-only round usually ends with a minute for you to ask something. The best questions to ask at the end of a consulting interview are specific to that interviewer's work, not to the firm's website.

 

What Mistakes Get Candidates Rejected in the First Round?

 

One of the biggest mistakes candidates make is preparing for a Big Four interview instead of a strategy interview. EY-Parthenon sits under the EY brand, so people assume the bar matches EY Consulting. The cases are considerably harder, and that assumption ends the process in round one.

 

The second common failure is arithmetic. A candidate who computes 12% of $500 million as $6 million instead of $60 million has usually lost the interview, no matter how good the structure was, because diligence work runs on getting numbers right.

 

Third is waiting to be led. Candidates trained on interviewer-led cases pause after each answer and expect the next question. In a candidate-led format that reads as an inability to drive work independently, which is the exact trait the role requires.

 

Fourth is building a structure that ignores the prompt. A memorized case interview framework applied to a case it does not fit is worse than a rough structure built for the actual question. Interviewers notice immediately when your buckets were written before you heard the problem.

 

What Happens After Your EY-Parthenon First Round Interview?

 

You usually hear back within one to two weeks. Glassdoor data from 2026 puts the average full EY-Parthenon process at about 31 days from application to offer, with Associate roles averaging 23 days across 79 submitted interviews and intern roles averaging 43 days across 21. EY's US careers page states that offer decisions are typically communicated within a week of your interviews.

 

Pass, and you move to a much longer final round interview. Expect two longer cases plus a senior leadership conversation, and in many offices a group case or a written case with a data packet. US super days frequently run three back-to-back interviews across three to four hours.

 

Get rejected and you still have something valuable available. EY offers unsuccessful candidates at both the first and final round the option of tailored feedback from one of their interviewers. One London candidate reported a 20-minute call that laid out specific improvement areas, which is far more useful than the generic rejection most firms send.

 

A short thank you email to each interviewer within 24 hours costs you nothing and keeps you visible while decisions are being made. Keep it to three sentences and reference something specific from the case discussion.

 

One planning note before you apply: EY's UK guidance limits candidates to one programme application within a six-month period, and asks rejected graduate and undergraduate applicants to wait six months before reapplying. Choosing the wrong track costs you half a year.

 

The EY-Parthenon first round interview rewards one thing above all others: solving a quantitative business problem quickly, out loud, without being led. If you do only one thing before your interview, run two timed 25-minute commercial due diligence cases back to back and see whether you can still deliver a clean recommendation at the end of the second one.

 

Frequently Asked Questions

 

How long is the EY-Parthenon first round interview?

 

Each first round case interview runs 25 to 45 minutes. EY's UK early careers page states that the Strategy route uses two 25-minute cases held back to back, so the full round takes about an hour. In the US, candidates more often report a single 45 to 60 minute interview that pairs a short fit conversation with a case.

 

Does the EY-Parthenon first round include behavioral questions?

 

It depends on the track. EY states that its UK Strategy first round includes no biographical questions at all, so you spend the entire time on the case. US candidates more commonly report 5 to 10 minutes of fit questions such as why consulting and why EY-Parthenon before the case begins.

 

How hard is the EY-Parthenon first round case interview?

 

Glassdoor rates the overall EY-Parthenon interview 3.3 out of 5 for difficulty based on 2026 data. The cases are quantitatively heavier than most Big Four interviews because so much of the work is commercial due diligence for private equity buyers. Expect growth rates, margins, and market sizing under real time pressure.

 

How long does it take to hear back after the EY-Parthenon first round?

 

Most candidates hear back within one to two weeks. Glassdoor data from 2026 puts the average full process at about 31 days from application to offer, and EY's US Consultant Program page says offer decisions are typically communicated within a week of your interviews. Campus timelines tend to move faster than experienced hire timelines.

 

Can you use a calculator in the EY-Parthenon first round?

 

Assume no calculator unless your recruiter tells you otherwise. EY's UK application tips ask candidates to bring a calculator and notepad to the EY Experience Day, but that is a separate assessment stage from the EY-Parthenon case rounds. Candidates consistently report doing first round case math by hand with pen and paper.

 

What happens if you fail the EY-Parthenon first round interview?

 

EY offers rejected candidates the option of tailored feedback from one of their interviewers, at both the first and final round stages. Take it, because you get specific detail on what went wrong. EY's UK early careers guidance also asks candidates to wait six months before submitting another graduate or undergraduate application.

 

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