Common LBO Interview Mistakes and How to Avoid Them
Almost nobody fails an LBO question by not knowing what an LBO is. They fail on the same eight or nine specific slips — in the sources and uses, in the cash flow line, in the exit math. Here's where the answer actually breaks, and what to say instead.
You can recite the definition of a leveraged buyout perfectly and still lose the question.
That's the frustrating part. The mechanics are not hard — a sponsor buys a company with debt and equity, the company pays the debt down with its own cash flow, the sponsor sells a few years later. Every candidate has that. What separates answers is whether the details underneath it hold up when the interviewer pushes on one.
Below are the mistakes that actually show up, grouped by where in the deal they happen. If you only fix the exit-math ones, you'll still be ahead of most people in the room.
Setting up the deal
Mistake 1: treating the purchase price as the only use of cash
A sources and uses table has to balance, and candidates routinely build one that can't. The uses side is not just “buy the equity.” It also includes repaying the target's existing debt, which usually comes due at a change of control, plus transaction and financing fees.
Sources are the new debt raised, the sponsor's equity check, sometimes cash already sitting on the target's balance sheet, and sometimes rollover equity from management or the existing owner. The sponsor's check is the plug — whatever the uses total that the debt and the other sources don't cover.
Say the plug out loud. It signals you understand the table is an identity, not a list.
Mistake 2: confusing what you bought with what you paid
“We buy the company at 10x EBITDA” is an enterprise value. The equity purchase price is that number less the debt you're assuming or retiring, plus cash. Candidates mix these two up constantly, then either double-count the existing debt (once in the entry multiple, again as a use) or leave it out entirely.
Pick one convention and be explicit about it. The cleanest version: enterprise value is the price of the business, existing debt gets repaid out of the proceeds, and the equity holders receive the rest.
Mistake 3: “a good LBO candidate is a fast-growing company”
Growth is nice. It is not the constraint.
The constraint is that debt has to get serviced on a schedule regardless of how the year goes. What makes a company financeable is predictable cash flow, modest maintenance capex, room under its current leverage, and something a lender can look at as collateral. A high-growth business that burns cash to fund that growth is a bad LBO candidate and a perfectly good venture or growth-equity one.
The middle years
Mistake 4: using unlevered free cash flow to pay down debt
This is the single most common technical error, and it comes from muscle memory: a DCF uses unlevered free cash flow discounted at WACC, because it values the business before financing. An LBO is the opposite exercise. Financing is the entire point.
What actually pays down the debt is the cash left after interest. Roughly: EBITDA, less cash interest, less cash taxes, less capex, less the increase in net working capital. If you say “unlevered free cash flow sweeps to the debt,” you've just told the interviewer the interest expense doesn't exist.
Mistake 5: taxing the wrong line
Under time pressure people compute taxes as EBITDA times the tax rate. Both subtractions that belong there are missing.
Taxes are levied on earnings before taxes, which is EBITDA less depreciation and amortization less interest. D&A shields income even though it isn't cash, and interest shields it too, assuming the interest is deductible. Getting this wrong overstates the tax bill and understates every year of debt paydown, which quietly compounds into a wrong IRR at the end.
Then add the D&A back on the cash flow line, since you only subtracted it to get to the right tax number.
Mistake 6: describing one undifferentiated pile of debt
Real structures are layered, and a candidate who says “the debt” the whole way through sounds like they've read about an LBO rather than seen one.
You don't need to price a credit agreement. You need to know that senior secured debt sits ahead of subordinated debt, that it's cheaper because it's ahead, that a term loan typically amortizes on a schedule while high-yield notes usually don't, and that a revolver exists to cover working capital swings rather than to fund the purchase. Excess cash flow sweeps to the most senior tranche first. That's what a debt schedule is doing.
Mistake 7: thinking a cash sweep and a cash build are different outcomes
Worth understanding because it's a favorite follow-up. If the company uses its free cash flow to repay debt, gross debt falls. If it just lets the cash pile up on the balance sheet, gross debt stays put but cash rises. Either way net debt falls by about the same amount, and equity value at exit is driven by net debt.
The difference is interest. Repaying the debt stops the interest clock on that balance; holding cash doesn't. So sweeping generates a bit more cash flow over the hold, but the first-order return effect is the same in both cases. Candidates who claim debt paydown creates value in some way that accumulating cash doesn't haven't thought it through.
Exit and returns
Mistake 8: assuming multiple expansion
Exiting at 12x after entering at 10x makes any deal look good. It also makes the analysis worthless, because you've assumed the answer.
The convention is to exit at the entry multiple, or below it. Multiple expansion is a real source of return, but it's the one the sponsor controls least — it depends on what the market will pay years from now. Underwrite the deal on the two levers you can actually influence, EBITDA growth and debt paydown, and treat any expansion as upside rather than as the base case. If an interviewer hands you a higher exit multiple, take it and note that you're taking it.
Mistake 9: forgetting the debt that's still there
The exit multiple applied to exit-year EBITDA gives you an enterprise value. That is not what the sponsor receives.
Equity proceeds are exit enterprise value less the net debt remaining at exit. Skip that subtraction and your MOIC is wildly too high. It sounds too basic to get wrong, and it gets wrong constantly, because by that point in a paper LBO the candidate has been doing arithmetic out loud for four minutes and is racing to a number.
Mistake 10: quoting a MOIC with no hold period
“We get 2.5x” is half an answer. Over three years that's an excellent outcome; over eight it's mediocre. MOIC measures how much came back, IRR measures how fast — and time is exactly what a fund with a finite life cares about.
Keep a few conversions in your head so you can sanity-check an IRR without a calculator: 2x in three years is about 26%, 2x in five years is about 15%, and 3x in five years is roughly 25%. If your stated IRR is far from the nearest of those, you've made an arithmetic error somewhere upstream. The full comparison, including where each metric misleads, is in the NPV vs. IRR guide.
Mistake 11: “more debt always improves returns”
More debt shrinks the equity check, so the same dollar of exit value spreads over a smaller base. Returns rise. That part is right.
The condition attached to it usually goes missing: that only holds while the return the business generates exceeds the after-tax cost of the debt funding it. Push past that and leverage works in reverse. It also raises the odds of tripping a covenant or missing a payment in a bad year, at which point the equity can go to zero regardless of what the model said. And in practice the ceiling isn't chosen by the sponsor at all — lenders decide how much debt the EBITDA supports.
A paper LBO you can run in your head
Interviewers often skip the discussion and just hand you numbers. Here's the whole shape of it, with arithmetic clean enough to do out loud.
- Entry. EBITDA of $100 at a 10x multiple gives a $1,000 enterprise value. Fund it with $600 of debt and a $400 equity check, ignoring fees for the moment.
- The hold. Over five years EBITDA grows to $130, and cumulative free cash flow after interest, taxes, capex, and working capital repays $250 of the debt. Net debt at exit is $350.
- Exit. Hold the multiple flat at 10x: exit enterprise value is 10 × $130 = $1,300. Subtract the $350 of remaining net debt. Equity proceeds are $950.
- Returns. $950 back on $400 in is roughly 2.4x MOIC. Over five years that's about a 19% IRR — comfortably between the 15% you'd get from 2x and the 25% from 3x, which is how you check it without a calculator.
Then say where the money came from, because that's the part interviewers are listening for: EBITDA grew, which lifted enterprise value at a constant multiple, and debt came down, which converted more of that enterprise value into equity. No multiple expansion anywhere in it.
If you want it slightly more realistic, take fees off the top — they raise the uses total, which raises the sponsor's check, which lowers the MOIC on the same exit. Say that you're excluding them rather than silently excluding them.
The delivery mistakes
Two more, and they aren't technical.
The first is narrating the model instead of the deal. A walkthrough that begins with tab structure and circular references has answered a question nobody asked. Start with what the sponsor is doing and why, then go to mechanics.
The second is refusing to make an assumption. Handed an incomplete prompt, plenty of candidates stall waiting for the missing input. State one instead — pick a tax rate, pick a hold period, say what you picked — and keep moving. Being wrong about an assumption you named is a much smaller problem than freezing, and interviewers will correct you if the number matters. The full LBO mechanics are worth having cold so you have something to fall back to when a prompt is deliberately thin.
How these get tested
None of this requires a faster calculator. It requires knowing which line the number goes on.
Run a few paper LBOs against a clock until the sources and uses, the cash flow line, and the exit subtraction happen without you thinking about them. The judgment questions are much easier to answer when the arithmetic isn't taking up the room.