How HR due diligence sizes people risk in M&A — pensions, key-person exposure, change-of-control triggers and hidden comp — and exactly where it feeds your FDD.
A buyer once shook hands on a services business at nine times EBITDA, then discovered in the fortnight before signing that seventeen senior consultants had change-of-control clauses entitling them to a full year's salary if the company changed owner. That single, un-modelled clause represented roughly £3m of day-one cash — more than the entire first-year synergy case. Nobody had lied. The information simply sat in an HR workstream that the deal team treated as a compliance box rather than a source of hard numbers. People risk is financial risk, and the analysts who understand where the two meet are the ones senior reviewers trust with the tricky files.
HR due diligence assesses the employment side of a target: contracts, compensation structures, pension and benefit arrangements, organisational design, key-employee retention risk, industrial-relations exposure, and employment-law compliance across every jurisdiction the business operates in. On a purely domestic deal it can be tightly scoped. On cross-border transactions it expands quickly, because employment protection, severance entitlement, and collective-bargaining obligations vary enormously by country — a target operating across five markets effectively needs five parallel legal reviews, each with its own rules on how expensive it is to let someone go.
It is usually run by employment lawyers and HR specialists, not by the finance team. That separation is precisely why it becomes a blind spot. As an FDD analyst you will not draft the HR report, but you inherit several of its conclusions directly into your numbers — and if you never read it, you will miss them. The professional habit is to treat HR DD as an adjacent evidence base, the same way you already lean on legal and tax colleagues within a coordinated financial due diligence process.
Four HR findings routinely land on the FDD desk, and each one changes a number you are responsible for.
The mental model that separates a good analyst from a great one: HR due diligence does not run parallel to FDD, it runs into it. Every material people finding eventually becomes an EBITDA adjustment, a net debt item, or a contingent cost — and someone has to catch the handoff.
HR DD is usually where key-person risk gets formally assessed: how dependent is the business on a small number of individuals — the founder, a rainmaking salesperson, a lead engineer — and what happens to revenue and delivery if they walk after completion. This is not a soft, HR-only concern. It reaches straight into earnings quality.
Revenue built on a founder's personal client relationships is structurally lower quality than revenue institutionalised across a team, contracts, and a brand — a distinction that belongs in your revenue quality analysis even though the underlying finding originated in HR DD. Where a single individual also happens to own the relationship with the target's biggest account, key-person risk and customer concentration compound: lose the person and you may lose the customer. A buyer typically manages this with retention packages, earn-outs, or handcuff arrangements written into the SPA — but the cost and structure of that fix depend on HR DD sizing the exposure honestly in the first place.
Numbers make the point better than adjectives. Take a mid-market target with headline EBITDA of £12.0m. Read purely off the P&L, it looks clean. Once you fold in the HR findings, the picture the buyer actually inherits shifts in two directions — a recurring earnings effect and a one-off cash effect.
| Item | Source | Type | Impact |
|---|---|---|---|
| Reported EBITDA | Management accounts | Baseline | £12.0m |
| Founder salary below market (add-back reverses on hire of a real MD) | HR remuneration benchmark | Recurring EBITDA | −£0.4m |
| Bonus accrual never formalised but consistently paid | HR / payroll review | Recurring EBITDA | −£0.3m |
| Normalised EBITDA | £11.3m | ||
| Change-of-control severance (17 senior staff) | HR contract review | Day-one cash / net debt | −£3.0m |
| DB pension deficit (funding shortfall) | HR + actuarial | Debt-like item | −£2.2m |
| Retention pool to hold two key persons for 24 months | HR retention design | Deal cost | −£0.9m |
The recurring finds knock £0.7m off maintainable earnings — at nine times, roughly £6.3m of enterprise value. The one-off items add £6.1m of debt-like and deal costs that hit the buyer's cash at or shortly after close. None of it was fraud, none of it was hidden in a locked drawer; all of it lived in the HR workstream and had to be carried across into the financial view before the equity cheque could be sized correctly.
There is a subtler point hiding in that table. The recurring and one-off effects are not independent of each other. A retention pool exists because of key-person risk; a change-of-control payout is large because the business chose to reward loyalty with generous contracts rather than higher base pay. Read the people cost as a system and you often find that the same underlying feature — a founder-centric, informally-run organisation — is generating exposure on several lines at once. That is why a buyer who treats HR as a standalone appendix tends to under-price the aggregate: each item looks tolerable in isolation, but they share a root cause and they all fall due around the same completion date.
The point for an analyst is discipline, not alarmism. Every one of these figures is estimable with the right evidence, and a buyer who has them in hand can fund them, negotiate them down, or restructure them into the deal. The failure mode is not that people costs are large — it is that they arrive as a surprise, after the price is agreed, when there is no room left to react.
The people workstream gets materially harder in two situations. The first is genuinely cross-border operations, where severance economics and consultation obligations differ by country: making twenty roles redundant might cost a fortnight's pay in one jurisdiction and the better part of a year's pay, plus a mandatory works-council process, in another. Any synergy case built on headcount reduction has to be haircut for these local realities before it is credible — a discipline that sits at the heart of honest synergies modelling.
The second is a carve-out, where the target has never existed as a standalone employer. Employees may sit on the seller's payroll, share the seller's pension scheme, or depend on a central HR function that does not transfer. Reconstructing a clean standalone people cost — new benefit arrangements, a standalone HR team, transitional service arrangements — is one of the least glamorous and most error-prone parts of a carve-out due diligence. Underestimate it and the standalone cost base you present is fiction.
Carve-outs also expose employees who are shared across the retained and divested businesses. A regional sales director who spends 40% of their time on the target and 60% elsewhere cannot be neatly cleaved in two. The buyer has to decide whether to hire a full replacement, share the person under a transitional arrangement, or absorb a capability gap — and each choice carries a different cost that HR DD should quantify rather than leave as a hopeful assumption. These allocation questions rarely make headlines, but they are exactly the sort of detail that turns an apparently clean standalone P&L into an optimistic one, and they belong in the same conversation as the wider standalone-cost debate.
You do not need to become an employment lawyer. You need three habits. First, ask early whether HR DD is in scope and who is running it, so you are not reconciling numbers in the final 48 hours. Second, request the findings that touch money specifically: the remuneration benchmark, the pension position, any change-of-control or enhanced-severance clauses, and the key-person assessment. Third, reconcile deliberately — every material HR finding should be traceable to a line in your EBITDA bridge, your net debt schedule, or a clearly flagged contingent cost, so that nothing falls between two reports. That reconciliation discipline is exactly what a clean FDD report structure is built to enforce, and it is where cross-workstream awareness quietly becomes visible to a reviewer.
Interviewers use HR due diligence to test whether you think in silos or in systems. A common prompt: "You're on an FDD engagement. Why should you care what the HR due diligence team finds?"
"Because HR findings turn into my numbers. Three of them matter most. First, remuneration: if HR benchmarks the founder's pay as below market for the role a buyer actually has to fill, that's a direct input to my management-remuneration add-back in the EBITDA bridge — I can't book that adjustment credibly without their benchmark. Second, debt-like items: a defined-benefit pension deficit and any change-of-control severance clauses are real claims on the buyer's cash, so they belong in my net debt build, not in a separate HR appendix nobody reconciles. Third, earnings quality: if the business depends on one or two key people — especially if one of them owns the biggest customer relationship — that's a revenue-quality and concentration issue as much as an HR one, and it usually drives retention structures in the SPA. So I'd read the HR report early, pull the findings that touch money, and make sure every one of them is traceable to a line in my bridge, my net debt, or a flagged contingent cost. Working in isolation from HR is how a buyer gets surprised at completion."
That answer works because it refuses to treat HR as someone else's problem — it names the exact numbers that change and shows you know where the handoffs live.
A business is, in the end, the people who show up to run it — and the contracts, promises and pensions that bind them are as real as any loan on the balance sheet. The analyst who reads the HR report, pulls out the numbers that bite, and threads them cleanly into the EBITDA bridge and the net debt build is the one who stops a buyer walking into a £3m surprise on the morning of completion. People risk is not the soft part of the deal. Priced properly, it is often the sharpest.
The Transaction Services Interview Programme (€119.99, one-time) includes a dedicated people-risk module — how to translate HR findings into EBITDA add-backs, net-debt items and contingent costs, with a worked change-of-control example and ready interview answers. Enrol today.
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