HR Due Diligence Checklist and Process for HR Departments

HR due diligence is the process of reviewing people, policies and workforce data to understand the risks and obligations that sit within an organisation. It gives HR teams a structured way to assess compliance, pay practices, contracts, culture, employee relations issues and any potential liabilities connected to the workforce.

Businesses typically carry out HR due diligence during mergers and acquisitions, organisational restructures, large TUPE (Transfer of Undertakings (Protection of Employment)) transfers, rapid expansion or when running internal compliance reviews. The aim is to build a clear, accurate picture of how the workforce is organised and whether current practices meet legal and regulatory expectations.

The process is especially important for large employers with multiple sites and complex staffing models. These environments often contain varied contracts, legacy policies and inconsistent record keeping, which can all increase the risk of hidden issues.

Large employers face a higher level of risk during mergers, restructures or compliance reviews.

Businesses with more than 500 employees often hold large volumes of HR data across multiple systems or sites, which can create gaps in visibility. These gaps can lead to hidden employment liabilities, outdated contracts, inconsistent policies, inaccurate payroll records or unresolved employee relations issues that may affect the outcome of a deal or transformation project.

Operational resilience is also a factor. Employers that operate across several regions manage varied shift patterns, contract types and local policies. Without a structured approach to HR due diligence, it becomes harder to understand how these differences affect risk, cost or future workforce planning.

Effective HR due diligence enables senior leaders to make informed decisions during M&A activity or major change programmes. It provides a clear picture of the workforce, highlights areas that need immediate attention and supports smoother integration or restructuring.

UK Regulations that affect due diligence

Regulators expect employers to show clear, documented compliance with employment status rules, redundancy requirements and TUPE obligations. Government guidance on employment status and worker rights explains that status must be assessed based on the actual working relationship. It also notes that employers should keep records that show how they reached their decision, since an individual’s rights follow directly from their status.

Statutory guidance under the Employment Rights Act 1996, together with government advice on redundancy, sets out the need for proper consultation, fair selection criteria and evidence of how decisions were made. Collective redundancy processes require employers to follow defined consultation steps and maintain accurate records.

Guidance on the Transfer of Undertakings (Protection of Employment) Regulations 2006 outlines specific duties for information sharing, employee liability data and consultation. These steps must take place within set timeframes and be supported by documentation.

Taken together, this framework shows that during organisational change, compliance cannot be assumed. It must be clear, well evidenced and capable of being defended if reviewed.

The HR due diligence process usually follows a clear sequence. Most reviews involve discovery, analysis, risk identification and a set of recommendations for leadership.

Pre‑due diligence preparation

Before any data gathering begins, the HR team should:

• Confirm the business objectives and the scope of the review
• Agree on the data, documents and systems that will be required
• Identify the stakeholders who need to be involved and any dependencies
• Set timelines, reporting expectations and internal communication protocols

This preparation step helps avoid delays once the review is underway.

Data and document gathering

HR teams then collect the core documents and records needed for assessment. This stage often includes:

• Standard employee records
• Employment contracts, handbooks and HR policies
• Pay and benefits data
• Organisational charts
• HRIS and payroll software exports
• Training records
• Absence, turnover and disciplinary information
• Collective bargaining agreements or works council materials if applicable

The aim at this point is to build a complete dataset so gaps can be identified early. An integrated HR system can reduce gaps in the dataset by pulling records, documents and workforce information into one place. Platforms such as PeopleXD Evo help teams collect consistent HR and payroll data, which makes the discovery stage more reliable and easier to manage.

Compliance review

The compliance element focuses on whether the organisation meets statutory requirements. This may include:

• Employment law compliance checks
• Right to work checking processes, including guidance from gov.uk on acceptable documents and follow‑up requirements
• Working time regulations
• Gender pay reporting obligations
• Health and safety governance
• Any existing or pending legal claims

This stage helps highlight areas where documentation or processes fall short of regulatory expectations. Maintaining accurate, up to date records is central to meeting statutory requirements. Using a system like PeopleXD Evo can support this by providing a single source of employment documentation, right to work evidence and audit‑ready compliance data.

Workforce analysis

A structured workforce review provides insight into the current capability and future needs of the organisation. HR teams often examine:

• Skills distribution and critical roles
• Workforce demographics
• Attrition rates and patterns
• Headcount planning and forecasting
• Pay benchmarking
• Culture indicators and engagement data

This analysis helps identify operational implications that may influence a transaction or change programme.

Risk analysis and reporting

The final stage brings the findings together in a clear, structured report. This typically covers:

• Key people‑related risks
• Areas of financial exposure
• Contractual or policy inconsistencies
• Cultural or behavioural issues that may affect integration
• Operational inefficiencies that could impact service delivery

The report should end with actionable recommendations so leaders can make informed decisions about the deal or programme. Clear reporting depends on reliable workforce data and the ability to surface risks quickly. PeopleXD Evo offers integrated analytics that help HR teams review trends, identify issues and present findings in a structured way during due diligence.

Mergers and acquisitions introduce a set of people‑related risks that go beyond a standard compliance review. HR teams need to examine how the workforce will be affected, whether there are legal obligations to meet and how easily the two organisations can operate together after completion. HR due diligence during mergers and acquisitions present a very real concern for HR professionals at the moment, as Personnel Today found in their research:

• 65% of HR professionals say they are not fully prepared to manage HR due diligence during potential M&A transactions
• 54% of companies expect M&A activity to increase, increasing pressure on HR due-diligence processes (workforce liabilities, contracts, pensions, compliance).

TUPE and employee protection

Where TUPE applies, the organisation taking responsibility for employees must protect their existing rights. This includes contractual terms, continuity of employment and information and consultation duties. HR teams should confirm which employees are in scope, whether the transfer qualifies under TUPE and what information needs to be provided to employee representatives. Clear documentation is important because these duties have strict timelines.

Cross‑border employment considerations

If the transaction involves employees in different jurisdictions, HR teams need to review local employment laws that may differ from UK standards. This can include rules on working time, dismissal, collective consultation or mandatory benefits. It can also require a review of how payroll, tax and social security arrangements will operate after the deal.

Culture compatibility and integration planning

Cultural alignment influences how well teams adapt after a merger. HR teams can review leadership behaviour, communication styles, decision‑making practices and employee feedback to understand whether the two organisations hold compatible expectations. Early visibility of potential cultural friction helps shape integration plans and informs which areas may need targeted support.

Leadership capability, morale and attrition risk

M&A activity can create uncertainty for employees. HR teams can assess leadership capability, communication effectiveness, workforce morale and current attrition patterns to anticipate how people may respond to the transaction. Early insight into these factors helps plan retention measures, onboarding support or leadership development activity.

Multi‑site operational considerations

Large organisations often operate with varied contracts, pay structures and local policies. During due diligence, HR teams can map these differences and determine where harmonisation will be required. This may include reviewing shift patterns, pay allowances, local policies or site‑specific agreements. Understanding these variations helps predict the scale of operational change needed after completion.

1. Inaccurate employment documentation - Missing contracts, unclear terms or inconsistent records that create uncertainty about rights and obligations.
2. Legacy payroll errors - Historic issues with holiday pay, allowances or overtime calculations that may need correction.
3. Misclassified workers - Incorrect employment status decisions that conflict with gov.uk guidance and affect tax, rights and liabilities.
4. High turnover hotspots - Localised attrition patterns that point to workload issues, leadership problems or culture concerns.
5. Culture conflicts - Differences in expected behaviours or leadership styles that may affect integration or future performance.
6. Pay equity gaps - Discrepancies in pay, including issues highlighted through gender pay reporting or internal benchmarking.
7. Outdated HR systems - Data quality problems or limited reporting capability that reduce visibility of key workforce information.
8. Regulatory non‑compliance - Gaps in right to work checks, working time rules, redundancy processes or TUPE documentation.

A unified HR system can help reduce many of these risks by bringing contracts, workforce records and payroll data into one place. PeopleXD Evo provides a structured way to manage documentation, improve data accuracy and support consistent reporting, which helps HR teams address compliance gaps and spot emerging issues earlier in the due diligence process.

Oli Quayle, AI Evangelist at The Access Group, sums up why outdated and disparate HR systems are no longer useful in large organsiations:

“I’m spending too much time on the tech, not enough time with my people. Frankenstack was a great intention—it was the right thing to do to get the depth—but you’re not leveraging that depth if you’re spending all your time servicing the integration between those two points. The promise didn’t quite live up. You think, ‘I’ll take product A and product B and integrate them and of course this will flow from here to here.’ But what’s happening now is customers are saying, ‘I’m spending too much time on the tech, not enough time with my people.’”

Mastering the Employee Lifecycle | Do the Best Work of Your Life Ep. 1

This checklist is designed for large employers preparing for mergers, acquisitions or significant structural change. It covers the core areas HR teams typically review to understand risks, obligations and operational impact.

Employee data and documentation

• Contracts
• Job descriptions
• Employment status
• Working patterns
• Right‑to‑work evidence
• Background check records
• Training and certification documentation

Pay, compensation and benefits

• Base salaries
• Bonus schemes
• Commission structures
• Pensions and auto‑enrolment
• Allowances
• Overtime rules
• Pay discrepancies
• Gender pay gap reporting (see the Government’s GPG guidance on reporting obligations)

HR policies and procedures

• Handbook review
• HR policies across all sites
• Grievance, disciplinary, performance, redundancy and absence processes
• Data protection practices
• Policy update cycles

Employee relations

• Active grievances
• Tribunal claims
• Disciplinary cases
• Union or works council agreements
• Records of strikes or industrial action

Organisational structure and workforce planning

• Org charts
• Role clarity
• Succession planning
• Critical skills and shortages
• Future workforce projections

Culture and engagement

• Engagement survey results
• Turnover statistics
• Values alignment
• DEI metrics
• Internal communications channels

HR systems and technology

• HRIS capabilities
• Payroll accuracy
• ATS and onboarding tools
• Data quality issues
• Integrations and reporting limitations

Large organisations often benefit from a single HR platform that integrates payroll software, analytics and workforce management in one place. A unified system such as PeopleXD Evo can help reduce data inconsistencies and provide the level of visibility required during due diligence. Celine, Dublin Port’s HR Manager, detailed how our unified HR software was able to analyse trends and help Dublin Port tackle them:

“One of the key challenges Dublin Port faced was analysing absenteeism trends. With the consultants in PeopleXD we are working towards establishing the necessary tools to track and analyse this data accurately. The insightful reports and easy-to-interpret data enabled the port to make informed decisions and address absenteeism issues effectively.”

HR due diligence is essential for large organisations because it provides a clear view of people‑related risks and gives leaders reliable information during mergers, acquisitions and other major changes. A structured approach helps identify issues early and protects the organisation from financial, legal and operational exposure.

Strong record keeping, reliable workforce data and consistent policies all contribute to a smoother due diligence process. These foundations reduce uncertainty, improve compliance and give leadership teams confidence that decisions are based on accurate information.

HR leaders can use this as a prompt to review whether their current systems, processes and documentation are ready for scrutiny. An audit‑ready function not only supports due diligence but also strengthens HR’s wider role in governance and risk management.

Organisations that use unified HR software with strong analytics, like PeopleXD Evo, often find it easier to maintain the level of visibility expected during mergers and large‑scale change.