Introduction 

When it comes to mergers and acquisitions (M&A), financial and legal assessments tend to take centre stage. But overlooking HR due diligence is one of the fastest ways to invite risk, disrupt culture, and compromise the success of the deal. 

Your people are your most valuable asset – and also your greatest variable.

At ThinkGlobal HR, we’ve seen firsthand how early, thorough HR due diligence not only identifies red flags, but unlocks value. It provides a roadmap for smoother integration, improved retention, and aligned strategy. If you’re not engaging HR from day one, you’re already behind.

Quick Tips

• Involve HR leaders during the pre-deal stage, not after the fact

• Assess employment contracts, benefits, and liabilities country by country

• Map workforce structures, talent risks, and compliance gaps

• Align compensation and equity schemes early to prevent retention issues

• Document culture, leadership behaviours, and organisational design

Why HR Due Diligence Matters Early 

Many businesses make the mistake of treating HR due diligence as an administrative task post-signature. But workforce issues are often the very factors that derail integrations. According to Globalization Partners’ M&A checklist, ignoring employment law compliance, benefits parity, and cultural alignment can result in fines, flight risks, or reputational damage.

By involving HR early, you:

• Understand total workforce costs (including bonuses, pensions, and accrued leave)

• Evaluate legal compliance with local labour laws

• Identify collective bargaining agreements or trade union considerations

• Assess risks around classification, immigration, or contract misalignment

One client we supported was expanding through acquisition into three new markets. HR due diligence revealed significant risk tied to misclassified contractors in two of them. We supported a shift to compliant models before integration, avoiding regulatory action and protecting brand trust.

Culture and Talent Mapping – Not Just Numbers 

HR due diligence is about more than headcount and payroll. It’s about understanding how people work, what drives them, and where friction may arise post-merger. Rizing identifies this as one of the four key HR roles across M&A phases: surfacing insights that shape integration.

Key areas to assess include:

• Leadership alignment and management style

• Performance and productivity norms

• Retention vulnerabilities among top performers

• Internal mobility, succession plans, and DEI benchmarks

In one case, cultural assessments flagged that one company’s “high-performance” bonus structure clashed with the acquired team’s collaborative norms. We worked with leaders to design a harmonised reward framework that maintained motivation without creating resentment.

The Hidden Liabilities You Can’t Afford to Miss 

HR is also where unseen liabilities often reside. These may include:

• Non-compliant employment agreements or undocumented benefits

• Discrimination or harassment claims under investigation

• Uneven global HRIS or payroll systems leading to inconsistent records

If missed, these can stall integrations or lead to costly legal consequences. That’s why we recommend using a structured HR due diligence checklist and working with global HR specialists who understand local regulations.

ThinkGlobal HR regularly partners with legal counsel and finance leads to provide a 360-degree view of people-related risks – from equity plan audits to statutory benefits mapping across jurisdictions.

Final Thoughts 

HR due diligence isn’t just a checklist. It’s a strategic pillar of any successful M&A. When done thoroughly and early, it lays the foundation for smooth transitions, high-performing teams, and a truly unified organisation.

What’s next for your global people strategy?

Let ThinkGlobal HR support your next M&A journey. Book a pre-deal or integration readiness audit with our expert team. We’ll help you identify risks, unlock talent opportunities, and build the people infrastructure your merger needs to succeed.