HR Due Diligence: 20 Questions to Ask

The data room had 847 documents. Fourteen folders. One was labeled “HR” and contained a headcount file, an org chart from last quarter, and a benefits summary that someone had clearly exported from the broker’s portal ten minutes before upload.

Three months after close, the acquirer discovered that 40% of the target’s US workforce was classified as exempt when they should have been non-exempt. The back-pay exposure was $4.2M. It was not in the data room. It was not in the reps and warranties. It was not in the purchase price adjustment. It was in a spreadsheet on a regional HR manager’s desktop, labeled “audit findings - do not share.”

HR due diligence is where deals go to hide their problems. Not because anyone is lying. Because the people who know where the problems are don’t get asked the right questions, and the people asking the questions don’t know what to look for.

These are the 20 questions I ask on every deal. Not all of them have answers in the data room. Some of them only have answers in conversations with the CHRO, the payroll manager, and the person who actually runs the HRIS.

Compensation and benefits (Questions 1-5)

These five questions surface the cost surprises that show up in Year 1. Comp and benefits are where the gap between “what the data room says” and “what the combined entity will actually cost” is widest.

1. What is the total loaded cost per employee by country, and how was it calculated?

Loaded cost is base salary plus benefits plus employer taxes plus any variable comp. The data room usually has base salary. The rest is scattered across broker reports, tax filings, and the finance team’s model. If nobody can produce the loaded cost on demand, the synergy model is built on base salary, which means it’s wrong by 25-40%.

Ask for the calculation methodology. Some companies include office space allocation. Some don’t. Some include contractor spend in headcount. Some don’t. The definition matters more than the number.

2. How many employees are on off-cycle comp structures?

Sign-on bonuses with clawback provisions. Retention agreements from a prior deal. Deferred comp. Guaranteed bonuses. These don’t show up in the standard comp file. They show up as surprises when you try to restructure and discover that terminating someone triggers a $200K payout.

Ask for a complete list of any compensation arrangement that isn’t standard base + bonus. In one deal, we found 23 employees on guaranteed bonuses that the acquiring company’s comp philosophy explicitly prohibited. Harmonizing cost $1.8M.

3. What is the benefits renewal date, and what did the last renewal look like?

Benefits renewals are the silent budget buster. A target company running on a December plan year with a renewal that hasn’t been negotiated yet is handing you an unknown liability. If the last renewal was a 12% increase, build that into Year 1 costs.

Also: are employees on the parent’s benefits plan (common in carve-outs), or do they have standalone plans? If parent-plan, TSA exit timing determines when you need your own. That clock starts at close.

4. What percentage of the workforce is exempt vs. non-exempt, and when was the last FLSA audit?

Misclassification is the single largest employment liability in US-based deals. The Department of Labor’s updated salary threshold (effective 2024) reclassified millions of workers. If the target hasn’t audited since the threshold change, you’re inheriting the exposure.

Ask when the last classification review was done. By whom. Whether it was legal counsel or an internal exercise. And whether there are any open complaints, investigations, or settlement discussions related to wage and hour.

5. What does the variable comp structure look like, and what are the payout triggers?

Commission plans, bonus pools, profit-sharing, equity vesting schedules. These create integration complexity because combining two different incentive structures is never “pick one.” The sales team on a quarterly commission plan won’t quietly switch to an annual bonus. The engineers with unvested stock options need a conversion ratio. Every plan has change-in-control provisions that may accelerate vesting or guarantee payouts at close.

Map every variable comp plan. Count the participants. Calculate the worst-case payout at close. This is the number the deal team needs before signing.

Retention and talent risk (Questions 6-10)

These questions identify who you can’t afford to lose, who’s already looking, and how much it costs to keep them.

6. Who are the top 40 roles by business impact, and what is their flight risk?

Not the top 40 by title. The top 40 by what happens if they leave. The regional sales director who owns $50M in customer relationships. The plant manager who’s the only person who knows how the legacy ERP interfaces work. The country HR director who has the works council’s trust.

McKinsey’s research says about 40 transformation-critical roles create 80% of total value. Identify them before close. Assess flight risk. Build individual retention plans. Generic retention bonuses waste money on people who were never leaving and underspend on people who are.

7. What does the voluntary turnover look like by function and tenure?

The headline turnover number is noise. What matters is turnover by function (is engineering at 25% while sales is at 8%?) and by tenure (are people leaving in Year 1, which suggests onboarding problems, or in Year 3-5, which suggests career ceiling problems?).

Ask for the last three years of turnover data, segmented. A function with accelerating turnover is a function where the integration announcement will trigger a wave.

8. Are there any pending or recent labor disputes, union negotiations, or works council proceedings?

This is a deal-breaker question that gets asked in legal due diligence but often doesn’t make it to the HR integration team. Active grievances. Pending arbitrations. Upcoming collective bargaining. Works council consultation requirements that affect the integration timeline.

In one EU deal, the works council had a pending consultation right on any organizational change affecting more than 10 employees. The integration plan called for restructuring 200. Nobody told the integration team until Week 4, by which point the timeline was already published.

9. What is the notice period distribution across the workforce?

In the US, this is simple: usually two weeks or at-will. Outside the US, notice periods range from one month (common) to six months (senior roles in Germany, UK) to twelve months (some C-suite contracts). This directly affects your integration timeline.

If you’re planning Day 90 synergy exits and 30% of the affected population has six-month notice periods, your synergy capture is delayed by three months. Your financial model needs to account for this.

10. What does the employer brand look like on Glassdoor, Blind, and LinkedIn?

Not a traditional due diligence question. But if the target’s Glassdoor rating is 2.8 with reviews mentioning “management doesn’t listen” and “no career growth,” you’re acquiring a retention problem that no bonus will fix. The comments also tell you what the real culture is, which is more useful than whatever the culture deck says.

Check LinkedIn for recent departures. Are senior people leaving? Are they going to competitors? This is free intelligence that most deal teams don’t look at.

Compliance and legal exposure (Questions 11-15)

These questions surface the liabilities that don’t appear on the balance sheet but can cost millions in Year 1.

11. What jurisdictions does the company employ in, and does it have legal entities in all of them?

This sounds basic. It is not. Companies routinely employ people in jurisdictions where they don’t have legal entities, using PEOs, EORs, or informal arrangements. Post-close, these arrangements may need to change. Entity formation in countries like Brazil, India, and China takes 3-4 months. Carve-outs are especially exposed here.

Count the countries. Count the entities. Find the gaps. Each gap is a project with a timeline.

12. What is the status of I-9 / right-to-work compliance?

Immigration and work authorization compliance is binary: you’re compliant or you’re not. Post-acquisition, the acquiring company inherits liability for the target’s I-9 compliance. An ICE audit in Year 1 is not theoretical. It happens. The fine is $252-$2,507 per violation for first offense, and the reputational cost is worse.

Ask whether I-9s have been audited in the last 24 months. By whom. What was found.

13. Are there any open EEOC charges, DOL investigations, or state-level employment complaints?

These should appear in the disclosure schedules. They often don’t, either because they’re considered immaterial or because local counsel hasn’t escalated them. Ask for a complete list. Include state-level complaints, which are often more numerous than federal.

14. What does the contractor workforce look like, and has it been audited for misclassification?

Contractor misclassification is the second-largest employment liability behind FLSA issues. If 15% of the target’s “workforce” is actually contractors, and some of those contractors look like employees (same hours, same badge, same manager, same desk), you’re inheriting the reclassification risk.

California’s ABC test, the EU’s updated directive, and the IRS’s evolving guidance all make this worse every year. Ask how many contractors there are, how long the average engagement has been, and whether legal has ever reviewed the classification.

15. What are the data privacy obligations for employee data across all jurisdictions?

GDPR, state privacy laws, country-specific employment data rules. Employee data is more sensitive than customer data in many jurisdictions. Cross-border data transfer restrictions affect where you can run payroll, who can access HR systems, and whether you can consolidate HRIS platforms.

In one deal, the target stored employee health data on a US-hosted platform with no data processing agreement. The GDPR exposure was not quantified until Week 6 of integration. The remediation cost was $400K.

Culture and organization (Questions 16-18)

These questions are harder to quantify and easier to skip. They’re also where most integration failures originate.

16. How does the organization actually make decisions, and who has informal authority?

The org chart shows reporting lines. It doesn’t show who actually gets things done. In every organization, there are people whose formal title understates their influence. The EA who controls the CEO’s calendar. The senior individual contributor who mentors half the engineering team. The country manager who’s been there 20 years and whose opinion carries more weight than the regional VP’s.

Interview 5-10 people at different levels. Ask who they go to when they need something done. The answers will not match the org chart.

17. What does the performance management cycle look like, and how does it handle underperformers?

This reveals cultural compatibility more than any values assessment. A company that does stack ranking and a company that does continuous coaching are not going to harmonize on Day 1. The performance cycle also affects integration timing: try to avoid launching a restructuring during the annual review period.

Ask what percentage of the workforce received the lowest performance rating in the last cycle. If it’s 0%, the system isn’t working. If it’s 15%, you have a culture that’s willing to have hard conversations.

18. What is the current state of the HRIS, and what does the data quality look like?

Clean data is the prerequisite for everything else. Workforce planning, synergy modeling, org design, comp analysis. All of it depends on data quality. If the HRIS has 58 different values for “country” across 46 actual countries, your first three months of integration will be spent cleaning data instead of making decisions.

Ask for a data quality report. Row counts by field. Null rates. The number of distinct values in fields that should be standardized (country, department, job level). If nobody can produce this, assume the data is bad.

Systems and operations (Questions 19-20)

19. What HR technology stack is in use, and what are the contract renewal dates?

HRIS, ATS, LMS, payroll, benefits admin, time and attendance. Map the full stack. Note contract renewal dates, because a contract renewing in 3 months is either a migration opportunity or a forced renewal at list price while you’re mid-integration.

Also: are any of these systems shared with the parent (in carve-outs)? If so, TSA exit timing for each system determines your technology roadmap.

20. What does the HR team itself look like?

How many HR FTEs per 1,000 employees? What’s the HR team’s turnover rate? Who are the single points of failure? If the global HRIS admin is one person with no backup, that’s a risk that deserves its own line item.

The HR team is the team that will execute the integration. If it’s understaffed, undertrained, or about to lose its best people, the integration is understaffed by definition.

The short version

HR due diligence is not a checkbox exercise. It’s the difference between a purchase price that reflects reality and one that doesn’t. Every question on this list has surfaced a material finding in at least one deal I’ve worked on. Most of the findings were fixable. All of them were cheaper to find before close than after.

The data room is a starting point. The real answers come from conversations with the people who do the work, not the people who approved the upload.

Want to see how these findings connect to post-close execution? Tour the platform or read about how HR integration actually works once the deal closes.

Related Reading

• HR Integration in M&A: The Missing Playbook
• M&A Retention Bonuses: The ROI Math Nobody Shows You
• Carve-Out Readiness: What to Build Before Day 1
• 100-Day M&A Integration Plan
• TSA Exit: Why Yours Will Take 18 Months