How-to guide: How to investigate workplace harassment complaints (UK)

Introduction

This guide will assist in-house counsel, private practice lawyers and human resource departments working in England, Wales and Scotland (GB) to deal with complaints of harassment in the workplace. The guide provides information about the relevant laws as well as practical guidance on how to carry out an investigation into a harassment complaint. This guide does not cover the law in Northern Ireland.

This guide covers:

The legal context in Great Britain
Investigating harassment complaints – initial considerations
Receipt of an allegation of harassment
Commencing an investigation
Investigation interviews
Analysis and findings
Remedial action
Post-investigation assessment of the workplace
Risks of getting it wrong

This guide can be used in conjunction with How-to guides: Overview of workplace discrimination and harassment law and How to comply with the employers’ duty to take reasonable steps to prevent sexual harassment in the workplace and Quick view: Protected characteristics under the Equality Act 2010.

Employers should be aware that the Employment Rights Bill 2024, introduced on 10 October 2024, aims to significantly enhance worker protections in the UK. Key provisions include granting day-one rights for unfair dismissal, paternity, parental, and bereavement leave, changes to sick pay and flexible working rights, protections against zero-hours contracts and restrictions on the use of ‘fire and rehire’ practices. New legislation will be introduced throughout 2025 and 2026. Further information can be found at UK Parliament: Employment rights bill and Employment Rights Bill: factsheets.

Section 1 – The legal context in Great Britain

There is no specific law against bullying in GB, and the legal context for harassment is largely framed by the Equality Act 2010 (EqA 2010). The EqA makes it unlawful to harass someone where conduct relates to a protected characteristic (see How-to guide: Overview of workplace discrimination and harassment law).

1.1 Harassment under the Equality Act 2010

Harassment, as defined by section 26, EqA 2010, is unwanted conduct related to a relevant protected characteristic, which has the purpose or effect of violating an individual’s dignity or creating an intimidating, hostile, degrading, humiliating or offensive environment for that individual. Section 26, EqA 2010 also defines harassment of a sexual nature, but for the purposes of this guide, the distinction is not relevant.

1.2 Harassment under the Protection from Harassment Act 1997

The Protection from Harassment Act 1997 (PHA) provides broader protection, not limited to the workplace or to protected characteristics. As well as exposing an employer to a claim in the civil courts, the PHA also makes it a criminal offence to cause harassment, alarm or distress.

1.3 Employer liability

If an employee resigns as a result of being bullied or harassed, they may present a claim of constructive dismissal to the employment tribunal. Constructive dismissal occurs when an employee establishes that they resigned in response to a fundamental breach of contract by the employer. This includes a breach of implied terms, such as the implied duty of trust and confidence between the employer and employee.

Employers can be held vicariously liable for the acts of their employees, which means that an employer can be taken to an employment tribunal based on a breach of the EqA 2010 if an employee or a group of employees harass a colleague.

It is therefore essential that employers ensure that they have robust policies in place for dealing with harassment, that employees are well informed about their rights and obligations in the workplace, and that any allegations of harassment (whether or not they relate to protected characteristics) are taken seriously by employers and are thoroughly investigated.

Since October 2024, employers have a positive obligation to prevent sexual harassment in the workplace. See How-to guide: How to comply with the employers’ duty to take reasonable steps to prevent sexual harassment in the workplace for further details.

Section 2 – Investigating harassment complaints – initial considerations

2.1 The purpose of investigating harassment complaints

The purpose of investigating allegations of harassment is to establish the facts of what occurred and to determine whether any misconduct has taken place. An investigation provides a structured process by which the employer can respond to accusations fairly, objectively and consistently.

There are multiple key reasons why a good investigation is important and these are listed below.

Employee well-being – the primary purpose of investigating harassment complaints is to ensure a safe, respectful, and inclusive workplace for all employees. Harassment can have serious negative impacts on the mental, emotional and physical health of employees, both on an individual basis and upon the wider workforce, particularly where there are allegations of a culture of harassment within a workplace.
Legal obligations – from a legal perspective, employers should investigate complaints to ensure compliance with anti-harassment and anti-discrimination laws, and in order to successfully defend claims of constructive dismissal from an employee who resigns after raising allegations of workplace harassment. Failure to conduct a proper investigation may result in legal consequences, including penalties and damages for the employer.
Reputation – prompt and thorough investigations can protect the employer’s reputation, both internally and externally. In this way the employer demonstrates their commitment to taking harassment seriously.
Conflict resolution – investigations can help to resolve conflicts, restore workplace harmony and ensure that any inappropriate behaviour is addressed and stopped.
Prevention – investigations also play a crucial role in preventing future harassment by identifying gaps in policies or training and highlighting areas for improvement in the organisation’s culture and practices.

2.2 Confidentiality

Confidentiality is a critical aspect of handling harassment allegations. Respecting the privacy of all parties involved ensures a safe environment for individuals to come forward with their concerns and protects the integrity of the investigation. It is important for employers to balance confidentiality with the need to disclose relevant information to those involved in the investigation, such as the investigation team, management and legal advisors. The individual accused of harassment, as well as relevant witnesses, will also likely need to be provided with certain information in order to have an opportunity to give their version of events. Employers should always keep in mind the principle of disclosing information on a need-to-know basis.

There are a number of reasons listed below why confidentiality is important.

Trust and safety – employers should emphasise to all employees and parties involved that their concerns will be treated with the utmost confidentiality. This assurance builds trust in the reporting process, encouraging individuals to come forward without fear of retaliation or breach of privacy.
Protecting complainants – many complainants are hesitant to report harassment due to concerns about their reputation or potential retaliation. By maintaining confidentiality, the employer can show a commitment to protecting the complainant’s privacy, helping them feel safer in reporting the incident.
Protecting the accused from false or incorrect allegations – if allegations made against an individual are investigated and proved to be unfounded, maintaining confidentiality can reduce the impact on the wrongly accused individual.
Protecting witnesses – witnesses to harassment incidents may also be reluctant to come forward if they fear negative consequences. Confidentiality allows witnesses to share crucial information without fear of undue pressure or intimidation.
Ensuring impartiality – confidentiality helps prevent bias or undue influence on the investigation process. When information is kept private, the investigation can proceed objectively, focusing on the facts rather than external pressures.
Legal compliance – respecting the confidentiality of the parties involved is essential for complying with data protection laws and human rights legislation. It demonstrates the organisation’s commitment to upholding employees’ rights to privacy.
Avoiding rumours and speculation – if an investigation becomes public knowledge prematurely, it can lead to rumours and speculation, potentially damaging the reputations of all parties involved. Confidentiality helps prevent the spread of unfounded information.
Maintaining workplace harmony – during an investigation into allegations of harassment emotions can run high, and confidentiality helps to prevent tensions from escalating and preserves workplace harmony until the matter is resolved.
Professionalism and ethics – confidentiality is a fundamental ethical principle in handling sensitive information. Upholding confidentiality demonstrates the organisation’s commitment to professionalism and shows respect for its employees.

Section 3 – Receipt of an allegation of harassment

Upon receipt of a complaint of harassment in the workplace there are a number of steps that an employer should follow.

3.1 Action upon receipt of the complaint

When an allegation of harassment is received, it is crucial for employers to take immediate action to properly document and record the complaint. This step establishes a clear starting point for an investigation and ensures that crucial information is preserved accurately. Employers should ensure they do the following:

Establish a point of contact – an employee is likely to direct a complaint of harassment to a specific individual (or a number of individuals) employed by the employer, such as a manager or HR representative. The employer representative who receives the complaint should establish the correct point of contact to progress the complaint. The point of contact might be flagged in a workplace policy or, if not, should be identified by the employer’s HR or legal team.
Provide acknowledgment and support – as soon as a complaint is received, employers should acknowledge receipt of the allegation to the complainant. Employers should provide assurance that the matter will be taken seriously, treated confidentially, and that the complainant will be protected from any form of retaliation for reporting the issue.
Initiate documenting – employers should document the complaint confidentially in writing or any other electronic format suitable for record-keeping. Employers should ensure that the documentation includes the following details:
- the name of the complainant and their contact information;
- date and time of the complaint’s receipt;
- detailed description of the alleged harassment incident(s), including the time, date, location, and any witnesses present, if available;
- the identities of the individuals involved, including the alleged harasser(s) and any potential witnesses;
- the nature and impact of the alleged harassment on the complainant; and
- any evidence or supporting materials provided by the complainant.
Preserve evidence – if the complainant provides any physical evidence, such as written messages, emails or photographs ensure that these items are securely preserved. This may include making copies of electronic evidence and ensuring its integrity.

3.2 Preliminary evaluation of the complaint

Employers should carefully review the allegation to gain a clear understanding of its nature, severity and context. The goal of the preliminary evaluation is to ensure that the employer understands the essence of the complaint before proceeding with an investigation. Employers should make sure that they take the following steps.

Identify key parties – this involves determining the identities of the individuals directly involved in the alleged incident, including the complainant (the person making the complaint) and the alleged harasser(s). Additionally, the employer should identify any potential witnesses who may have relevant information.
Assess the allegation’s details – based on the information available, the employer should consider whether the complaint is specific, coherent, and supported by any evidence or witness statements.
Identify the nature of harassment – the employer should ascertain the type of harassment alleged, such as verbal, physical, or cyber harassment, and determine if it aligns with any protected characteristics.
Identify what policies are potentially within the scope of the complaint – such as policies relating to harassment; whistleblowing, equality and diversity; and grievance.

3.3 Preliminary action

Based on the above, the employer should determine if any immediate action is required, such as separating the involved parties temporarily, providing support to the complainant, or safeguarding any potential evidence.

Section 4 – Commencing an investigation

4.1 Form the investigation team

Conducting a harassment investigation requires a skilled and impartial team to ensure fairness, accuracy and professionalism throughout the process. Generally, the choice is between an in-house team or an independent external investigator. If an employer lacks the internal resources or expertise to handle complex or high-profile cases, engaging an external investigator can be an effective solution, as it allows the organisation to tap into specialised knowledge without the need for permanent staffing.

4.1.1 In-house team

In-house human resources (HR) professionals are often well versed in handling workplace issues, including harassment complaints, and can either carry out the investigation or provide support to another internally appointed investigator. HR are familiar with company policies, procedures, and the organisational culture, which can aid in gathering relevant information and conducting interviews.

However, a balance must be struck to ensure an internal investigator had no direct involvement in the events that led to the harassment complaint, in order to maintain objectivity and impartiality during the investigation.

Employers should ensure that the in-house team members have received proper training on harassment investigations, including legal requirements, interview techniques and documentation procedures.

4.1.2 External investigator

An external investigator brings an independent perspective to the investigation, avoiding any potential bias or conflict of interest that could arise with an organisation’s internal investigation. This is especially crucial for serious or sensitive allegations involving high-ranking employees or complicated situations. An external investigator is less likely to have pre-existing relationships within the organisation, which ensures a higher level of confidentiality and impartiality in handling sensitive information. Using an external investigator can also avoid in-house staff from spending time away from their day-to-day duties dealing with an investigation.

Employers should look for an external investigator with experience in conducting harassment investigations and a strong understanding of the legal framework surrounding workplace harassment. External investigators are often HR consultants or lawyers.

4.2 Planning the investigation process

Once an investigator has been appointed, they should produce a roadmap for the process, to ensure that the investigation is thorough, organised and focused on gathering the necessary evidence. A roadmap should always be subject to adjustment if new information comes to light during the process. This ensures that the investigation remains comprehensive and thorough.

Planning the investigation process should include the steps described below.

Defining the scope – this should be defined with clearly identified specific allegations, incidents, and individuals involved. The investigator should determine the timeframe in which the alleged harassment occurred and any relevant locations.
Identifying the key questions – the investigator should formulate the key questions that the investigation will aim to answer.
Identifying and gathering the information needed to answer the key questions and substantiate the allegations – this may include documentary evidence such as emails and text messages, witness evidence, policies within scope and other forms of evidence such as CCTV footage or photographs.
Identifying and prioritising the individuals who need to be interviewed as part of the investigation.
Outlining the approach and structure of the interviews – the investigator should plan how to maintain confidentiality and ensure a comfortable and safe environment for interviewees to share their experiences.
If the investigation involves an internal team, divide responsibilities among team members based on their expertise and availability. For external investigators, the employer should ensure they are fully briefed on the scope and objectives of the investigation.

The policies within scope of the investigation may provide a timeline for the investigation by setting deadlines for completing the various steps of the investigation and for when the final report should be due. The investigator must ensure that the investigation plan aligns with the organisation’s policies and any applicable laws.

Section 5 – Investigation interviews

Interviews as part of a harassment investigation should be conducted with the utmost care to ensure fairness, impartiality and sensitivity to the emotions of those involved. Investigators should conduct each interview with a neutral and objective mindset and should avoid displaying bias or favouritism towards any party. The focus should be on gathering factual information. The following guidance will be helpful to follow during the interview process.

Plan interview logistics – interviews should be scheduled at a time and location convenient for the interviewees. Investigators should consider whether to conduct interviews in-person, via video call, or over the phone, and should respect any requests for breaks, or adjustments to accommodate individual needs. To avoid any potential interference or intimidation, investigators must conduct interviews with each party separately. A note-taker – usually a HR representative – will often be present during the interviews.
Interviewing the complainant:
- Actively listen – allow the complainant to share their account of the alleged harassment without interruption. Actively listen to their story, taking note of relevant details and emotions expressed.
- Ask open-ended questions – encourage the complainant to provide specific details by asking open-ended questions. This approach allows them to share their perspective freely.
- Be empathetic – show empathy and understanding towards the complainant’s experience, validating their emotions and concerns.
Interviewing the alleged harasser:
- Remain impartial – approach the interview with an open mind, without presuming guilt or innocence. Treat the alleged harasser with respect and ensure they have an opportunity to respond to the allegations.
- Seek an explanation – allow the alleged harasser to provide their side of the story and explain their perspective on the events in question.
- Avoid accusations – refrain from making accusations during the interview, as the purpose is to gather information and not to confront the individual.
Interviewing witnesses:
- Gather relevant information – seek witness statements to corroborate or refute the allegations. Encourage witnesses to share any information they have that relates to the incident(s) in question.
In all interviews avoid leading questions – investigators should ask open-ended questions to allow witnesses to provide their own account without being influenced by suggestive phrasing.
Document details – witness statements should be recorded accurately by a note-taker or the investigator, including names, contact information, and specific details. It is crucial to take detailed notes during each interview to accurately record the information provided. The date, time and location of the interviews should be noted, as well as the names and roles of those involved. Interviewees should be asked to read and sign the interview notes to confirm their accuracy.
Follow-up interviews – if necessary, investigators should conduct follow-up interviews to clarify any discrepancies or obtain additional information.

Employers should be prepared to provide emotional support to interviewees who may experience distress during the interviews. Employers should offer resources for counselling or assistance if needed.

Section 6 – Analysis and findings

Once the investigation is complete the employer should analyse the information to reach well-informed conclusions. This will include the steps listed below.

Organise and review – the investigator should gather all the information, statements and evidence collected during the investigation and organise the data in a systematic manner to facilitate a comprehensive review.
Verify credibility – the investigator should assess the credibility of each piece of evidence and the individuals providing it. The reliability of the witnesses should be considered, taking into account the consistency of their statements and the corroborating evidence, if any.
Consider context – this involves examining the evidence within the context of the workplace environment and any relevant policies, procedures, or cultural factors that may have influenced the situation.
Identify key issues – pinpointing the critical issues arising from the evidence that need further scrutiny is an important step. The focus should be on the key elements of the allegations and whether they are substantiated or not.
Weighing evidence – the strength of the evidence must be weighed for each side of the case in order to determine whether the evidence supports the complainant’s allegations or not.
Identify patterns – the investigator should look for any patterns or recurring themes in the evidence that may shed light on the overall situation or behaviour patterns of the individuals involved.
Address discrepancies – any discrepancies or inconsistencies in the evidence should be examined and attempts should be made to resolve them through further investigation or clarification.
Consult legal and HR experts – seek advice from legal counsel and HR professionals, if needed, to ensure the evaluation complies with relevant laws, company policies and best practices.
Formulate findings – based on an evaluation of the evidence, the investigator should determine whether the allegations are substantiated, partially substantiated, or not substantiated.
The investigator must thoroughly document the analysis process, including the rationale for findings and any challenges faced during the evaluation.
Prepare the investigation report – the investigator should compile the findings, analysis and any recommendations into a comprehensive investigation report. The report should be clear, concise, and supported by the evidence collected during the investigation.

Employers should ensure that they follow any applicable workplace policies that impact upon the scope of the investigator’s role. For example, a grievance policy might limit the role of the investigator to a fact-finding exercise only, with the grievance outcome decision being made and communicated by a different employer representative, based on the information compiled during the investigation.

Section 7 – Remedial action

Once the investigation has concluded, and if the evidence supports the harassment allegation, it is crucial to take prompt and decisive action to address the misconduct and prevent its recurrence. Where it has been established that harassment has taken place, it is highly likely that disciplinary action will follow; however, a disciplinary process must still be adhered to (see Checklist: Carrying out a disciplinary process).

Employers should ensure the following:

Any proposed action aligns with the organisation’s anti-harassment policy, disciplinary policy, code of conduct and any other relevant policies, as well as any applicable laws. Seek legal or HR guidance if needed.
The safety and well-being of all employees is taken into account when deciding on disciplinary measures. The employer’s actions should aim to create a safe and respectful workplace for everyone and may include suspension of the harasser during the disciplinary process.
Disciplinary measures are applied consistently to avoid any perception of favouritism or discrimination.
The reasons behind any disciplinary measures are clearly documented.
The outcome of the investigation and any anticipated disciplinary process are communicated to both the complainant and the alleged harasser.
Any disciplinary actions are implemented promptly and effectively.
The situation is monitored to ensure harassment has ceased.

Section 8 – Post-investigation assessment of the workplace

After completing a harassment investigation, the employer should conduct a thorough review of its existing policies and training programmes to ensure that they effectively address and prevent workplace harassment. Key parts of this learning exercise are listed below.

Review the findings of the investigation to identify any patterns or recurring issues related to harassment, paying attention to specific areas where the policies or training may have fallen short in preventing or addressing harassment.
Assess whether the organisation’s existing policies on harassment, discrimination, and workplace conduct adequately cover the types of incidents and behaviours uncovered during the investigation.
Based on the investigation’s findings, revise policy language to be more explicit, inclusive and comprehensive. Ensure that the policies clearly define harassment, outline reporting procedures, and provide information on available resources and support.
Evaluate the effectiveness of the existing reporting mechanisms for harassment complaints. Employers may consider implementing anonymous reporting options and ensuring that employees are aware of their rights and protections when reporting incidents.
Review and, if necessary, update the disciplinary measures outlined in the policies to ensure they align with the seriousness of harassment offences. Clearly communicate the potential consequences for engaging in harassment.
Evaluate the content and effectiveness of the organisation’s harassment prevention training programmes. Ensure that training addresses specific scenarios and behaviours highlighted in the investigation. Enhance training to promote a culture of respect and inclusion. See also the information on preventing sexual harassment in How-to guide: How to comply with the employers’ duty to take reasonable steps to prevent sexual harassment in the workplace.
Consider employee training on bystander intervention, empowering employees to recognize and address harassment when they witness it.
Assess the impact of making harassment prevention training mandatory for all employees and consider the frequency of training sessions to reinforce awareness and understanding of the policies.
Provide specialised training for supervisors and managers on recognising and responding to harassment complaints, and ensure they understand their responsibility to prevent and address harassment in their teams.
Implement mechanisms to monitor policy compliance and ensure that employees and management are adhering to the revised policies.
Schedule periodic reviews of policies and training to ensure they remain relevant and effective. Stay up to date with legal developments and industry best practices.

Employers should clearly communicate any updates or changes to policies and training programmes to all employees.

Section 9 – Risks of getting it wrong

Getting a harassment investigation wrong can expose an organisation to a wide range of risks, both financial and non-financial.

9.1 Financial risks

An employer that does not carry out an adequate investigation into allegations of harassment in the workplace faces the following financial risks:

Legal costs – if the investigation is flawed or biased, the organisation may face legal challenges from both the complainant and the alleged harasser. Legal proceedings can be costly in terms of legal fees, court expenses, and potential settlement amounts.
Compensation and damages – in cases of successful discrimination or personal injury claims, the organisation may be required to pay compensation and damages to the affected parties. These costs can be significant and impact the financial stability of the organisation.
Loss of business – negative publicity resulting from mishandling a harassment investigation can lead to a loss of business and potential damage to client relationships.
Increased insurance premiums – if the organisation’s insurance policies cover harassment claims, a poorly managed investigation may result in increased insurance premiums.

9.2 Non-financial risks:

In addition to the financial risks outlined above, employers may also face the following issues:

Reputational damage – mishandling a harassment investigation can tarnish the organisation’s reputation, leading to a loss of trust from employees, customers, business partners and the public.
Employee morale – a poorly handled investigation can negatively impact employee morale and trust in the organisation’s leadership. Employees may perceive a lack of commitment to their well-being and may become disengaged, leading to reduced productivity and increased staff turnover.
Negative culture – an ineffective investigation may perpetuate a culture of harassment and intolerance within the organisation, as employees may feel discouraged from reporting future incidents.
Loss of talent – highly skilled and valuable employees may choose to leave the organisation if they perceive that harassment issues are not taken seriously, leading to a loss of valuable talent.
Investor perception – investors may view an organisation with a history of mishandling harassment investigations as a higher risk, leading to a potential decrease in share value and investor confidence.

9.3 Constructive dismissal

Mishandling a harassment investigation may lead to a hostile work environment, causing the complainant to resign due to the organisation’s failure to address their concerns adequately. This could result in a claim of constructive dismissal, where the employee argues they were effectively forced to resign.

9.4 Discrimination claims:

If the investigation is perceived as biased or unfair, the complainant may claim discrimination based on factors such as gender, race, or other protected characteristics. This could result in a separate discrimination claim, compounding the organisation’s legal and financial risks.

9.5 Personal injury claims:

In cases where harassment has caused emotional distress, anxiety, or other psychological harm, or where there was a physical injury as a result of the actions of the harasser, the complainant may pursue a personal injury claim against the organisation, seeking compensation for the damages suffered.

Additional resources

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