Belgium Private Investigations Act: 2026 Compliance Guide

Why does the 16 December 2026 deadline matter?

The Act is not a new regime taking effect in 2026. The Law of 18 May 2024 regulating private investigations entered into force on 16 December 2024, replacing the 1991 law governing private detectives. Its rules on investigation methods, interviews, documentation, data processing, reporting and confidentiality already apply.

But employers were given additional time to meet one crucial requirement. Article 65 requires the authority to investigate an employee, and the procedures governing that investigation, to be set out explicitly and transparently in internal policy. Under the transition period provided by Article 180, employers have until 16 December 2026 to put those rules in place.  

Until then, an employee investigation may proceed without the Article 65 regulations, provided the Act’s other applicable requirements are met. After the deadline, their absence could affect the legal validity of the investigation itself.

Article 101 requires a judge to examine whether investigation findings were obtained in accordance with the Act and lists Article 65 among the provisions prescribed on pain of nullity. Not every procedural error will invalidate an investigation, but an employer that has not established the required internal framework could be left with credible findings it cannot safely rely on in disciplinary action or legal proceedings.

Could the Belgium Private Investigations Act apply to your investigation?

If your organisation investigates suspected employee misconduct, you should assess the Act’s application before evidence is collected, not once the investigation is already underway.

The key question is whether someone has been instructed to gather information about particular people, organisations or events to protect the employer’s interests in an actual or potential conflict. In practice, this may include familiar cases involving fraud, theft, conflicts of interest, unfair competition, misuse of confidential information, manipulation of records or other serious misconduct.

Who conducts the investigation does not determine whether the Act applies. An inquiry may fall within scope whether it is handled by HR, compliance, legal, internal audit, IT, a central group team or an external provider.

Some activities are excluded, including certain work performed by lawyers and statutory auditors, specific cybersecurity activities, audits that do not collect personal information to investigate adverse events, and investigations arising solely from a legal obligation. These exclusions should not be assumed without examining the purpose and scope of the work.

This is particularly important when a whistleblowing report triggers the investigation. Work conducted strictly to fulfil a legal duty may be excluded, but the position can change if the inquiry expands or the findings are used for another purpose.

When opening a case, record why the Act does or does not apply. Revisit that assessment if the allegations, investigation methods or intended use of the findings change.

Does your investigation team require authorisation?

Possibly. The answer depends less on the team’s name than on how investigation work is organised in practice.

Start by asking whether your organisation has a function that conducts private investigations on a recurring basis or presents itself as an internal investigations service. If it does, the function may qualify as a structured internal private-investigation service and generally require prior authorisation from the minister responsible for Home Affairs. Identification and suitability requirements may also apply to its personnel.

The position is different for HR teams handling occasional incident investigations involving their employer’s own employees. Article 43 allows members of an HR department to conduct this work without an identification card or membership of an authorised investigation service. This exemption does not remove the obligation to follow the Act, nor should it automatically be extended to investigations led by compliance, audit, IT or another function.

For multinational organisations, the analysis may be more complex. A central team that regularly investigates matters for several group entities may amount to a structured internal service even if investigations are only one part of its wider role.

Review how cases are allocated in practice: who receives them, how frequently investigations are conducted, whether investigation duties appear in job descriptions and which group entities the team serves. Record the conclusion and confirm that any external provider is properly authorised before assigning work.

What do your internal investigation rules need to explain?

Your rules should answer the questions an employee or an investigator would reasonably ask: When can an investigation begin? Who is allowed to conduct it? What methods can be used? What rights do those involved have? What happens to the findings afterwards?

At a minimum, the framework should define:

• the circumstances that may justify an investigation; for example naming the categories that your company handles (fraud, theft, conflicts of interest, misuse of confidential information) rather than a general reference to “misconduct”;
• who can commission, authorise, conduct and oversee it by role or by function (HR, compliance, legal, group investigations team) not just “management”;
• which evidence sources and investigation methods are permitted, for example email and system logs, badge data, and interviews, and categories of information that may never be investigated, such as political opinions, trade union membership, health data, religious beliefs, sexual behaviour, and racial or ethnic origin;
• how employee rights, interviews, consent, privacy and confidentiality will be protected, including what an employee is told before an interview and their right to end it; and
• how findings may be used, reported, retained and securely destroyed.

The Act does not prescribe a single format. The rules may appear in a collective labour agreement, workplace regulations or a dedicated policy. What matters is that they are explicit, transparent and implemented through the appropriate Belgian process. Employment and privacy advice will be important when deciding how to adopt them.

The practical test is whether your organisation can show which rules applied when an investigation began and that employees had been properly informed. This requires clear ownership, version control and evidence of communication, not simply a document stored on an intranet.

For multinational employers, an existing global policy may provide a useful foundation. It should still be reviewed against Belgian requirements and the investigation process used locally. If the written rules and the actual workflow do not match, the policy alone will not resolve the risk.

What does the process look like from intake to closure?

When a serious allegation arrives, the instinct is often to begin gathering evidence immediately. Under the Act, however, decisions made at the outset – who investigates, what information is collected and how the findings may be used – can affect the entire case.

A practical workflow should cover four stages.

1. Pause and assess the case

Before reviewing emails, access records or other evidence, decide whether the proposed inquiry falls within the Act. Check whether an exclusion applies, whether the investigator or service requires authorisation and whether your internal rules allow the investigation. Record that assessment. If the position is unclear, obtain advice before the inquiry develops beyond its original purpose.

2. Define and document the assignment

Set clear boundaries before work begins: what is being investigated, why the employer has a legitimate interest, who will conduct the work, which methods may be used and how the findings are intended to support a decision.

The formal record depends on who conducts the investigation. Where the investigator is not employed by the organisation commissioning the work, Article 66 requires a written assignment document covering the scope, legitimate purpose, intended use and expected duration. Where the organisation also employs the investigator, an assignment register must instead record the client, the precise assignment and the dates on which it was given and completed.

3. Keep the investigation within its boundaries

Evidence-gathering methods must be lawful, necessary and proportionate to the allegation. Investigators should document what they collect, the steps they take and any decision to change the original scope.

Interviews require particular care. The person must consent, understand why the interview is taking place and how their statements may be used, and be free to end it. Following a consistent process protects employee rights and makes it easier to demonstrate how the findings were obtained.

4. Decide, notify and close the case

The investigator’s authorised representative must provide a written report within one month of the final investigative act. The employer then has 30 days to confirm whether it intends to use the findings.

If it does, affected individuals must be notified and allowed to exercise their rights, subject to limited exceptions. If it does not, the reports and information must be destroyed.

Finally, apply the relevant retention periods: five years for the assignment register, generally three years for the investigation file, and only as long as necessary or legally required for the employer’s copy of the report.

What should Belgian employers prioritise now?

With fewer than 100 days remaining, the main challenge is likely to be coordination rather than awareness. Policies can stall during legal review or internal approval, while investigation procedures often involve several teams that do not usually work from the same timetable.

Employers should work backwards from 16 December and focus on the points most likely to delay implementation:

• Put one person in charge. Give the project a clear owner who can coordinate compliance, HR, legal, privacy, audit and IT and resolve gaps between their responsibilities.
• Set the approval timetable now. Allow enough time for Belgian legal review, any necessary employee consultation, internal approval, publication and communication.
• Identify everyone who may initiate or conduct an investigation. They need to know when the Act may apply, which process to follow and when to pause and seek advice.
• Test a realistic case. Run a sample allegation through the full process to find unclear handovers, missing records or deadlines that no one owns.
• Check investigations already in progress. Pay particular attention to cases that may remain open after 16 December 2026 and confirm how the new rules will affect them.

The objective is to ensure that, when the next serious allegation arrives, the people involved can apply the rules consistently and show how each decision was made.

Policy management helps employers control which investigation rules are approved and communicated. Whistleblowing and incident management helps teams apply them consistently and document each decision.

Together, they create a traceable link between the policy in force and the investigation conducted, an important part of preparing for the Belgium Private Investigation Act deadline.