How to Prepare for Investment Banking Interviews

Key takeaways

IB interviews test four pillars: technical, behavioural, commercial awareness, and firm-specific — strength in one does not compensate for weakness in another
Start preparing 8-12 weeks before with 1-2 hours daily; split time 40% technical, 25% behavioural, 20% commercial, 15% firm research
Practise out loud — reading answers in your head is not the same as delivering them under pressure
Depth beats breadth: know core concepts cold rather than studying everything superficially

The Four Pillars of IB Interview Prep

Every IB interview tests four areas. You need to pass all of them — being strong in one does not compensate for weakness in another.

Pillar	What It Tests	Example Questions
Technical	Hard skills — accounting, valuation, M&A, LBO, DCF	"Walk me through a DCF," "What happens when depreciation increases by £10M?"
Behavioural	Fit — personality, stories, motivation	"Tell me about yourself," "Why IB?", "Tell me about a failure"
Commercial awareness	Genuine interest in finance	"What is happening in the markets?", "Tell me about a recent deal"
Firm-specific	Whether you have done your homework	"Why this firm?", "Which of our deals interests you?"

The Preparation Timeline

8-12 Weeks Before: Start with the foundations. Work through the three financial statements until you can explain how they link without hesitation. Understand the DCF process end-to-end. Learn the EV-to-equity bridge. These are non-negotiable — they come up in every interview.

4-8 Weeks Before: Move to application. Build a paper LBO from memory. Practise walking through a deal. Prepare your STAR stories for behavioural questions. Start tracking weekly market news and deals.

1-4 Weeks Before: Polish and stress-test. Do mock interviews with friends or mentors. Practise under time pressure. Research your target firms: recent deals, team structure, culture. Prepare specific questions for each interviewer.

Final Week: Do not cram new material. Review your strongest technical answers. Rehearse your "tell me about yourself" out loud. Get proper sleep. Prepare your outfit and logistics.

How to Structure Daily Study

Aim for 1-2 hours per day during the 8-12 week period. Split your time:

40% Technical: Work through questions, build models, practise mental math
25% Behavioural: Write and rehearse STAR stories, practise "why IB" answer
20% Commercial awareness: Read FT/WSJ, track 2-3 deals per week
15% Firm research: Understand your target firms' recent deals, culture, and structure

The Mistakes That Cost Offers

Common mistake Over-indexing on technicals. Many candidates spend 100% of their time on accounting and valuation, then fail the behavioural round because they have not prepared their stories.

Over-indexing on technicals: Many candidates spend 100% of their time on accounting and valuation, then fail the behavioural round because they have not prepared their stories.

Studying too broadly: You do not need to know everything. You need to know the core concepts cold. Depth beats breadth in interviews.

Not practising out loud: Reading answers in your head is not the same as saying them. Your first answer to "walk me through a DCF" should not be in the actual interview.

Insider tip "What is happening in the markets?" is asked in almost every interview. Track 2-3 deals per week and read the FT or WSJ daily. If you cannot answer this question confidently, you look like you are not genuinely interested in finance.

Ignoring commercial awareness: "What is happening in the markets?" is asked in almost every interview. If you cannot answer it confidently, you look like you are not genuinely interested in finance.

Take Your Preparation Further

Download our free Interview Day Checklist for the complete preparation timeline. For everything you need in one package, see the Complete IB Prep Bundle — interview guide, behavioural prep, networking strategy, and cover letter templates.

Ready for personalised feedback? Book a 1-on-1 mentoring session with an experienced IB/PE professional.

How to Prepare for Investment Banking Interviews: A Complete Guide