With the 2024 social elections approaching, the topic of the technical business unit (TBU) is already on the agenda for many employers.

At the level of this TBU, the Works Council (WC) and/or the Committee for Prevention and Protection at Work (CPPW) will be established.

How TBUs are structured in the company will often impact the thresholds for organising social elections, and when those thresholds are reached, the potential number of candidates and mandates.

Since the TBUs do not necessarily coincide with the legal entities or branches within the company (which is also true for the WC and CPPW), employers can - to a certain extent - influence what is considered one TBU.

Some employers prefer to keep the TBUs separate, for example to avoid having to organise social elections for the whole company or because they do not want to mix the employee representatives or trade union delegations.

Other employers have a multitude of TBUs and would prefer to merge them.

In this article, we will therefore discuss (I) the economic and social elements that may or may not play a role in determining TBU(s). Consequently, we will also address the practical, organisational elements that cause different legal entities to be considered as one TBU - and which can be influenced to some extent.

Furthermore, the (II) disadvantages and (III) advantages of merging different TBUs will be discussed.

Economic and social cohesion or autonomy

To be considered as one TBU, a number of conditions of economic and social cohesion must be met (see below).

There is a rebuttable presumption that several legal entities constitute a TBU if it can be demonstrated that there is at least one element of economic cohesion and certain elements of social cohesion. Only the employees and representative trade union organisations may invoke this presumption.

On the other hand, if the employer wants to have one TBU recognised, they must fully demonstrate the economic and social criteria of cohesion, without being able to rely on the legal presumption.

The assessment of TBU is an interplay of many factual elements. It is also the case that some indications will weigh more heavily than others.

Indications that play a role include:

Economic cohesion/autonomy

Social cohesion/autonomy
  • mutually coordinated or complementary activities;
  • belong to a single economic group, even if it is a foreign group (an economic group was defined by case-law as: a set of distinct and independent companies by law, but in fact subject in one way or another to an economic power, which at various levels ensures unity of decision, convergence of policy and coordination of potential of the companies);
  • same registered office;
  • identical persons participating in the boards of directors of the various entities. The fact that persons participate in the management of both companies is already sufficient to fulfil the economic criterion. The fact that the companies are engaged in separate activities or whether or not they work under contract for each other does not alter this. However, the effective policy and management of the company must be at issue;
  • joint accounting, legal service, administration, security service, maintenance service, ...;
  • the various entities are offshoots of a common ancestor.

Physical organisation of work

  • use of the same or nearby buildings;
  • shared parking, reception desk, ...;
  • same clothes;
  • communal facilities, cafeteria;
  • common intranet, telephony, ICT infrastructure;
  • common time clock;
  • same courses;

Personnel policy and management (these are usually the criteria to which judges attach the most importance)

  • joint personnel department, unless it only has the executive role of payroll administration and does not operate its own personnel policy;
  • common personnel policy;
  • same remuneration policy;
  • same forms to apply for holidays;
  • same replacement holidays;
  • the HR manager of the different entities is the same person (the decision-making power of any separate HR managers also plays a role);
  • use of similar standard employment contracts;
  • mutual movements, exchange of personnel,...;
  • one common internal prevention service;
  • same car-policy;
  • same evaluation system;
  • same disciplinary procedure;
  • compulsory membership of a pension fund;
  • same gift on special occasions;

Social consultation

  • same company collective agreements;
  • in both entities, the same negotiator/spokesperson acts on behalf of the employer;
  • belong to the same joint committee, although this in itself has been described as a rather weak or even irrelevant criterion in case law. Conversely, belonging to different joint committees is not proof of a separate personnel policy and management, since this results from the main activity of the legal entity in question.

Socio-cultural criteria

  • group outings;
  • joint football team;
  • undeniable group feeling;
  • staff party, Saint Nicholas party, family bbq.


Indications that do not play a role include:

  • difference in hourly schedules, since this depends on the activity performed;
  • matters resulting from the entities being under a different joint committee;
  • same company auditor;
  • it is possible for a person to sit on the board of one company and work at another, without affecting the personnel policy of the second company.

Risks and disadvantages of one TBU

The threshold for organising social elections is at an average employment of 50 employees at TBU level. From that number on, a CPPW must be established at TBU level. From an average of at least 100 employees, a WC is also established.

Where there are differences in terms of working and wage conditions between the different entities/branches, a merger of TBUs may result in the unions asking for equal treatment in terms of working conditions for the entire TBU.

Contamination from certain issues may also occur from one TBU to other entities/sites.

Unions are also likely to oppose the merger when there is already a union delegation and/or WC and/or CPPW at the level of the different entities. This is because a merger of TBUs can then result in fewer mandates being needed in social elections and thus fewer candidates. As a compromise, employers often choose to work with a separate CPPW at the level of the legal entity or activity.

With one TBU, it sometimes happens that one trade union has the upper hand. In this case, proposals that are actually more widely supported can sometimes be blocked.

Benefits of one single TBU

By merging the TBUs, in principle only one WC and one CPPW should be established, which will reduce the number of mandates/placeholders.

As already indicated above, the number of protected workers will therefore be able to decrease in some companies when several TBUs and bodies already existed. The fewer bodies, the fewer candidates and therefore the fewer protected workers.

When merging into a single TBU, the union delegations will also mix. Since it is sufficient to conclude collective agreements that apply to the entire company or one or more branches with only one representative trade union organisation, this creates opportunities to reach new compromises.

In branches where only one trade union is represented and where that union delegation has so far been able to block certain proposals, this union will be able to be sidelined in the event of a merger. It will then suffice for a representative of another trade union, which currently only has representation in certain branches, to sign a CBA that is binding on the other branches.

The merging of employee representation bodies will also lead to more uniformity and a clear line. There will be no or less room for exceptions or inconsistencies between the different entities.

Last but not least, a reduction in representation bodies will also lead to a reduction in the associated administrative burden, as well as a reduction in meetings.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.