When Does a Workplace Complaint Require a Formal Investigation?
An employee says their manager is bullying them. Two coworkers give very different accounts of an argument. Someone reports inappropriate messages but asks you not to do anything.
What should an employer do next?
Every workplace complaint needs an appropriate response. Some concerns can be addressed through a documented review, clearer expectations or management support. Others require a structured investigation to establish what happened before decisions are made.
The important question is whether the information you have triggers an obligation to investigate, and what process will fairly address it.
In this article
What is a formal workplace investigation?
A formal workplace investigation is a structured process for examining allegations and making findings based on the available evidence.
It usually includes defining the allegations, interviewing the people involved, reviewing relevant records, giving the person named in the complaint an opportunity to respond, and documenting findings.
Its purpose is to establish facts. It is different from mediation, which helps people work toward an agreement, or coaching, which helps someone improve their behaviour.
A formal investigation does not automatically require an external investigator. A suitable internal investigator may be able to conduct it. Equally, hiring someone externally does not remove the need for a fair, well-defined process.
When is an employer required to investigate?
Canadian employers need to consider the requirements that apply to their workplace, including occupational health and safety legislation, human rights obligations, workplace policies and any collective agreement.
For example:
Alberta: Employers must investigate incidents of workplace harassment or violence and prepare an investigation report.
Ontario: Employers must ensure an investigation appropriate in the circumstances is conducted into workplace harassment incidents and complaints. A verbal or informal report can trigger that obligation.
British Columbia: Employers must have and follow procedures for responding to bullying and harassment reports, including how investigations will be conducted.
Federally regulated workplaces: A separate harassment and violence resolution process applies. Employers should follow that process rather than assume provincial procedures apply.
These obligations do not mean every concern requires the same number of interviews or the same length of report. They do mean an employer cannot dismiss a potential harassment issue simply because the employee did not complete a complaint form.
The seriousness and complexity of the allegations affect the scope of the investigation. They do not, by themselves, determine whether an investigation obligation exists.
Signs a complaint needs a structured investigation
The following circumstances are strong reasons to move beyond a routine management conversation.
The allegations involve serious misconduct
Complaints involving sexual harassment, discriminatory conduct, threats, violence, retaliation or other serious misconduct need careful assessment and will often require a structured investigation.
The investigation should determine what happened and whether the conduct breached the relevant policy. Avoid deciding the outcome before the evidence has been gathered.
A single incident can be serious enough to warrant this process. You do not need to wait for a pattern to develop.
Important facts are disputed
One employee says a supervisor threatened them. The supervisor denies it. There may be messages, witnesses or previous incidents that help establish what occurred.
A quick conversation with the supervisor is unlikely to resolve that dispute fairly.
Different accounts are a reason to examine the evidence, rather than a reason to close the complaint. The absence of an eyewitness also does not automatically mean an allegation cannot be substantiated.
The concern may affect more than one employee
Several employees describe similar conduct. A complaint suggests a pattern involving a manager, department or work location. Previous concerns were addressed informally, but the behaviour appears to have continued.
A structured investigation can help determine whether the allegations are connected and whether the scope needs to include additional incidents.
Keep that scope defined. An investigation should not become an unrestricted search for everything anyone dislikes about a person.
The outcome could have significant consequences
If the findings could lead to serious discipline, termination or significant changes to someone’s role, a careful fact-finding process is especially important.
The employer needs a sound basis for decisions. Both the employee raising the concern and the person responding to it need a fair opportunity to provide relevant information.
The complaint involves leadership or a conflict of interest
A complaint about the owner, executive director, senior leader or HR professional may be difficult to investigate internally.
Consider who would appoint the investigator, who controls their work and who would receive the findings. If those relationships compromise impartiality, external support may be the appropriate choice.
When might a more limited response be appropriate?
Some complaints concern unclear expectations, routine disagreements or administrative errors.
For example, an employee may question an incorrectly recorded vacation balance. Two colleagues may disagree about responsibility for a task. Someone may be unhappy with a reasonable scheduling decision.
After clarifying the concern and checking for underlying allegations, the appropriate response may involve reviewing records, explaining a decision, correcting an error or setting clearer expectations.
For harassment allegations, a focused investigation may sometimes be sufficient where the facts are straightforward. It still needs to satisfy the applicable requirements and be documented.
The important distinction is between a proportionate investigation and no investigation at all.
Before choosing an informal response, ask:
Have we clarified the alleged behaviour, checked the relevant policy and requirements, and documented why this response is appropriate? If the concern involves harassment, discrimination, retaliation or disputed misconduct, a conversation alone may not be enough.
Is it workplace conflict, performance management or harassment?
The employee’s label is a starting point. You need to understand the behaviour behind it.
An employee who says “my manager is bullying me” might be describing reasonable feedback about missed deadlines. They might also be describing repeated public humiliation, threats or discriminatory comments.
Ask for specifics:
What was said or done?
When and where did it happen?
Who was involved or present?
Are there relevant messages or documents?
Has it happened before?
Reasonable management actions are generally distinguished from harassment, but the way those actions are carried out matters.
A manager can have a legitimate performance concern and still handle it inappropriately. A performance issue does not automatically invalidate a complaint about the manager’s behaviour.
What if the employee asks you not to investigate?
An employee may want the behaviour to stop without participating in a formal process. They may worry about retaliation, relationships or career consequences.
Listen to those concerns. Explain the next steps and discuss available support. However, avoid promising that the employer will take no action.
Depending on the allegations and applicable requirements, you may need to proceed even if the employee does not request an investigation or later withdraws their complaint.
Also avoid promising absolute confidentiality. Information may need to be shared to investigate fairly, protect employees or take corrective action. Explain who may need information and why.
Anonymous complaints should also be assessed. They may contain specific, verifiable information, although anonymity can limit the conclusions an investigator is able to reach.
Can mediation replace a workplace investigation?
Mediation can help resolve some workplace conflicts, especially when people want to improve their working relationship.
It does not establish whether an allegation is substantiated, and it should not be used to bypass an investigation obligation.
Before recommending mediation, consider the alleged conduct, any power imbalance, whether participation would be voluntary and what the applicable process requires.
In some situations, mediation or relationship repair may be useful after an investigation. In federally regulated workplaces, resolution options operate within a specific legislative process.
What should employers do when a complaint arrives?
1. Address immediate safety concerns
Assess whether anyone is at risk. Consider temporary arrangements or support while the matter is reviewed. If there is an immediate threat, use the appropriate emergency response.
Interim measures should protect people and the integrity of the process without assuming the allegations have been proven.
2. Record the concern and preserve relevant information
Document what was reported, when it was received and who received it.
Preserve relevant emails, messages, schedules and other records before they are deleted or overwritten. Handle collection in accordance with privacy obligations and the investigation’s scope.
3. Assess the required process
Review the applicable requirements, workplace policies and any collective agreement.
Clarify the allegations enough to decide how they should be investigated. Avoid trying to settle credibility through a few informal conversations before the process has been established.
4. Choose an appropriate investigator
Consider experience, impartiality, availability and any conflicts of interest.
The investigator needs the skills to assess evidence and conduct fair interviews. They should not be someone involved in the events or someone whose relationship with the people involved compromises objectivity.
5. Explain the process and monitor for retaliation
Tell the people involved what to expect, how confidentiality will be handled and who to contact with concerns.
Make the expectations around retaliation clear. Monitor for changes such as exclusion, pressure on witnesses or punitive treatment connected to participation.
6. Close the loop
Once the investigation is complete, communicate the outcome as required and take appropriate action.
In Ontario, the affected worker and the responding employee must receive written results and information about corrective action. This does not mean providing everyone with the full investigation report.
Follow-up may also include policy changes, training, management support or monitoring.
When should you use an external workplace investigator?
External support is worth considering when:
The complaint involves an owner, senior leader or someone in HR.
No internal person can investigate impartially.
The allegations are complex or particularly sensitive.
Your team lacks investigation experience or capacity.
Previous responses have not adequately addressed the concerns.
An external investigator can provide independent fact-finding. The employer still needs to manage safety, communication and decisions arising from the findings.
Not sure whether your complaint needs a formal investigation?
You do not need to know whether misconduct occurred before seeking advice. That is what a properly scoped investigation is designed to determine.
A&A Consulting helps employers assess workplace complaints and determine the appropriate next steps. We also conduct workplace investigations into allegations such as harassment, bullying and other workplace misconduct.
If you have received a complaint and are unsure how to proceed, let’s talk about the situation and the support you need.
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Up to date as of October 13, 2026. This article is not intended to replace legal or professional advice. Please check with a professional (even if it's not us) before proceeding - investigations and their outcomes can have serious legal ramifications.
