Joris DeeneAn employee may prepare for a future competitive activity during the term of his employment contract, but he may not compete with his employer while the contract is in effect. Article 17, 3° of the Employment Contracts Act prohibits any act of unfair competition during the term of the contract, and labor courts consider any competition by an employee against his or her own employer to be unfair. The threshold is reached with the first actual act of competition: approaching a customer, submitting a quote, or taking an order.
In short:
- A single visit to a potential client as a representative of a competitor was deemed sufficient grounds for immediate dismissal by the Brussels Labor Court on September 26, 2025, even though the employee was on sick leave at the time and was not paid for that visit.
- According to the Labor Court in Mons, registering a domain name, incorporating a company, or acquiring a stake in a competitor are permissible preparatory acts; however, according to the Labor Court in Ghent, submitting a bid for a government contract is not.
- Since the enactment of Article 20 of the Act of October 7, 2022, engaging in a non-competing secondary occupation has, in principle, been permitted, but on August 26, 2025, the Brussels Labor Court nevertheless upheld a clause requiring prior written consent, due to the safety risks associated with the position.
Why Competition During the Term of a Contract Is Always Unfair
The duty of loyalty is the employee’s obligation to perform his or her employment contract in good faith and not to harm the legitimate interests of his or her employer for as long as that contract remains in effect. It is based on two provisions: Article 17, 3°, b) of the Employment Contracts Act requires the employee to refrain from acts of unfair competition both during and after the term of the agreement. Article 5.73 of the Civil Code adds to this the general rule that every contract must be performed in good faith.
The word “unfair” in Article 17 might give the impression that fair competition is permitted. Case law interprets it differently. An employee may not compete with his or her employer at all, not even fairly. The Brussels Labor Court stated in a ruling dated December 14, 2016, that competition by an employee is always unfair precisely because an employment contract exists (Labor Court, Brussels, December 14, 2016, 2014/AB/595). As early as 1976, the Court of Cassation held that an employee who formed a company with third parties that partially competed with his employer committed a serious breach of duty (Supreme Court, May 5, 1976).
This prohibition is broad. It applies outside of working hours and during periods when the employment contract is suspended, such as in the event of illness. It applies regardless of whether the employee is working for themselves or for a third party, as a self-employed person or as a salaried employee. And it applies even when the employee does not receive a single cent for their competitive activities. The Labor Court of Hainaut outlined these principles in 2017 (Hainaut Labor Court (Charleroi Division), September 5, 2017, 16/1.876/A).
There is, however, one way out. The employer can authorize the competing activity, in which case it becomes lawful. The Labor Court of Liège reiterated this in 2023 (Liège Labor Court (Liège Division) April 25, 2023, 2022/AL/307). Anyone who wishes to start a side business in the same industry as their employer would therefore be wise to request that permission in writing and keep a copy on file.
What is the penalty for an act of unfair competition?
A compelling reason is a serious breach that immediately and permanently renders any further professional collaboration between the employer and the employee impossible. According to labor courts, an act of competition during the term of the contract is, in principle, an example of this. The employer does not need to prove any damage in such cases: the breach of the duty of loyalty is sufficient.
On September 26, 2025, the Brussels Labor Court applied this to a high-profile case (Labor Court, Brussels, September 26, 2025, 2018/AB/948). An employee who was on leave with medical certificates introduced himself to a potential client as an account manager for a company that competed with his employer. He did so under an unpaid agreement to gain experience in the field. To the court, this made no difference: it constituted an exploratory activity on behalf of a competitor, and even a single such visit constitutes an act of unfair competition that justifies dismissal for cause. Neither the lack of compensation, nor the employee’s incapacity to work, nor the limited scope of the work performed outweighed this.
Malicious intent is also not required. On October 24, 2022, the Labor Court of Hainaut ruled on the case of an employee who had started a side business in the same sector and the same region as his employer, and who posted photos and a video on his own company’s Facebook page of work he had performed for his employer (Hainaut Labor Court (Binche Division), October 24, 2022, 21/1.427/A). The fact that customers might therefore think his own business had performed the work was sufficient. It did not matter that he had no malicious intent or that the employer could not point to any specific harm. The risk of confusion in and of itself was enough.
Two factors make the situation even worse. Anyone who engages in competitive activity during working hours will have that held against them as an aggravating circumstance. And anyone whose contract already includes an explicit non-compete clause for the duration of the agreement will find it more difficult to claim ignorance.
In addition to termination, the employee may also be ordered to pay damages. The partial limitation of liability under Article 18 of the Employment Contracts Act, which holds the employee liable only for fraud and gross negligence, does not help the employee in this case: engaging in competitive activity against one’s own employer constitutes, at a minimum, gross negligence. If the competitive activity was carried out during working hours, the employer may reclaim the wages for those hours and, in addition, the lost profits resulting from the customer contacts the employer consequently missed out on.
Finally, the court does not consider only the legal entity of the employer. In January 2026, the Ghent Labor Court ruled that the competitive nature of an activity is also assessed in relation to the group to which the employer belongs, when it is established that the affiliated companies engage in similar or complementary activities (Ghent Labor Court, January 9, 2026, 2024/AG/235). What matters is the economic reality of the group, not the organizational chart.
What an employee is allowed to do: prepare without competing
A preparatory act is a step taken by an employee with a view to future self-employment, without the employee having already offered goods or services to the market. That distinction is decisive. Dismissal for cause requires an actual act of competition; mere preparation for such an act is not sufficient.
Case law has not always been so clear on this point. Earlier rulings also considered actions whose sole purpose was to prepare for a competing activity to be impermissible, and some legal scholars argued that a valid non-compete clause in the contract lowered the bar. Recent case law has settled this debate in favor of the employee. In 2017, the Brussels Labor Court explicitly stated that the non-competition clause only takes effect after the end of the contract and that preparations made during the term of the contract do not constitute competition (Labor Court, Brussels, December 13, 2017, 2015/AB/574).
So what exactly is allowed? In 2015, the Labor Court in Bergen drew up a list (Arbh. Bergen, December 22, 2015, 2013/AM/335): registering a domain name and creating a temporary web page, incorporating a company, acquiring a stake in a competing company, gathering information, and even conducting negotiations or entering into transactions, as long as the activity itself has not yet commenced. The Liège Labor Court had ruled similarly a month earlier (Labor Court of Liège (Namur Division) November 17, 2015, 2014/AN/15).
In 2018, the Labor Court in Liège provided a striking example (Liège Labor Court (Hoei Division), May 14, 2018, 11/17/A). An employee was preparing to open his own store and sought information about this from one of his employer’s suppliers. The court found this to be normal. Anyone who wants to open a store gathers information, including from suppliers known to their employer. Moreover, the planned business was different—even though some products overlapped—and would be located elsewhere. There was no act of unfair competition, let alone gross negligence.
In another ruling, the same court emphasized that the breach must have actually occurred. The intention to compete—even when expressed by the employee—is a plan, not an act. As long as the plan has not been put into action, there is no breach.
Where Preparation Ends and Competition Begins
This distinction ceases to apply when the preparatory acts are accompanied by unfair conduct, acts contrary to the employer’s interests, or acts that in reality already constitute the start of a competing business activity. The Hainaut Labor Court articulated this distinction in the Facebook page case, and the Charleroi Court of First Instance had already done so in 2017.
In January 2026, the Ghent Labor Court drew a clear line regarding government contracts. An employee had submitted a bid for a public contract that was similar to her employer’s activities and was dismissed for cause. She argued that submitting a bid is a preparatory act. The court did not agree with her. Applying for a business registration number or purchasing professional equipment constitutes preparation; submitting a bid does not. In the case of a public contract, competition takes place between the opening and the closing of the award procedure. Once the contract has been awarded, no one else may offer the same services to the same government entity for the entire duration of the contract. Competition therefore does not begin with the performance of the contract, but with the bid, and the bid itself is already an act of competition.
One final point to consider: actions taken during the term of the contract that seem harmless in and of themselves may take on a different meaning in hindsight. If a former employee systematically takes over his former employer’s clients shortly after leaving, or if a significant portion of the staff follows him, this may be an indication that steps toward this were already taken during the term of the contract. An employer who suspects this may still invoke these facts.
How does an employer prove that a competitive activity has taken place?
Cases in which the ground of urgent cause is rejected usually have one of three causes: there is a lack of evidence supporting the facts, the three-business-day deadline has not been demonstrated, or the facts cited turn out, upon closer examination, to be merely preparatory. The existence of a second job, a business plan, or contacts with a competitor does not in itself prove prohibited competition. The employer must present concrete evidence.
The first element is the similarity of the activities. They do not need to be identical: it is sufficient that the goods or services are interchangeable for the customers. The question is whether a customer of the employer can consider the employee’s offerings as an alternative. If the employer sells a wide range of trips and the employee sells only cruises in another country, then the activities are complementary rather than competitive.
The second element is the distinction between an act of unfair competition and a mere professional error. Anyone who refers a customer to a competitor’s solution in order to help that customer—without personally benefiting from it and without the order ultimately being placed—may be committing an error, but not necessarily a serious one.
The third element is the most relevant today: what social media reveals. On June 25, 2025, the Brussels Labor Court ruled on the case of a saleswoman at a beauty product chain who posted photos on her Instagram account in which she promoted a competing product (Labor Court, Brussels, June 25, 2025, 2023/AB/361). She referred to herself as a “young entrepreneur” and mentioned a “beauty products store,” and she had a significant number of followers. The court found that this was not sufficient. There were no prices listed, no terms of sale, and no evidence that the product was actually for sale. Announcing a project on a social network without providing concrete details does not constitute commercial activity.
This contrasts with the Facebook case from 2022. In that case, the employee presented work he had done for his employer as his own achievements, in the same industry and the same region. The difference lies not in the medium but in what is happening: an announcement versus an offer that misleads customers.
Can an employee start their own business alongside their job if it doesn't compete with it?
The prohibition applies only to competing activities. Since 2022, a legal framework has been in place for a second job that does not compete with the employer’s business. Article 20 of the Act of October 7, 2022, which the Directive on Transparent and Predictable Terms and Conditions of Employment The Labor Code stipulates that an employer may not prohibit an employee from working for other employers outside of his or her work schedule, nor may the employer treat the employee unfavorably for doing so, except where permitted by law.
The duty of loyalty also remains in effect. A side job becomes problematic when it is performed during working hours, when it compromises the employee’s quality of work or availability, when it jeopardizes safety, or when the employee uses the employer’s equipment, data, files, or other resources for that purpose. The latter constitutes a breach in and of itself, even if the side job does not compete with the employee’s primary employment. Anyone who uses their employer’s customer database or a company laptop for their own business activities violates the duty of loyalty and, moreover, comes close to trade secret law, that Article 17, paragraph 3, subparagraph (a) of the Employment Contracts Act has explicitly extended this provision to employees since 2018.
Is the employee required to inform his employer? The law does not address this issue. However, the duty of loyalty may justify at least notifying the employer, especially if the employee works for a supplier or partner of his employer, or holds an interest in a company with which his employer does business. In 2022, the Labor Court in Liège ruled on the case of the financial director of a sports club who, without his employer’s knowledge, handled the accounting for directly competing clubs (Liège Labor Court (Liège Division) March 17, 2022, 2020/AL/582). The conflict of interest was obvious, the employment regulations required prior authorization, and the employee had not requested it. Immediate cause.
An exclusivity clause is a contractual provision that prohibits or restricts an employee from engaging in other professional activities—including non-competing ones—during the term of the agreement. The validity of such a clause is not self-evident. Article 6 of the Employment Contracts Act declares null and void any clause that curtails the employee’s rights or imposes additional obligations on the employee in violation of the law, and Article 20 of the Act of October 7, 2022, now grants the employee an explicit right to engage in secondary employment.
Nevertheless, on August 26, 2025, the Brussels Labor Court upheld a clause requiring the employee to obtain his employer’s prior written consent for any secondary employment (Labor Court, Brussels, August 26, 2025, 2024/AB/184). The position involved operating electrical equipment in a sensitive environment at professional clients in the pharmaceutical sector. In that context, the employer was permitted to verify whether the secondary activity did not jeopardize safety or the proper performance of the contract. The court thus linked the validity of the employer’s right to the nature of the position, not to a general right of the employer to monitor secondary employment.
Legal analysis and interpretation
Is a quote really considered competition?
The January 2026 ruling by the Ghent Labor Court is strict, and it is worth taking the objection seriously. In 2015, the Mons Labor Court expressly permitted an employee to engage in negotiations and even enter into transactions during the term of his contract with a view to his future employment. In the ordinary course of business, an offer is a proposal that the other party may accept or reject. Why, then, would an offer constitute an act of unfair competition, whereas a negotiation does not?
The Ghent Court’s answer lies in the unique nature of public procurement. In a normal market, after receiving a quote, the customer remains free to place an order with the employer tomorrow or next year. With a public contract, however, the situation is different: whoever wins the contract closes off the market for the entire duration, and the only place where competitors compete is the award procedure itself. Whoever submits a bid there takes the place that would otherwise have been open to the employer’s customers. That reasoning holds true for public contracts. It cannot simply be applied to the private market, where a quote submitted to one of the employer’s customers is indeed an act of competition—but only because the employee is approaching one of his employer’s customers, not because the quote itself closes off the market. Anyone citing the ruling should therefore do so with that qualification in mind.
Is an admission clause consistent with Article 20 of the Act of 2022?
The ruling of the Brussels Labor Court dated August 26, 2025, warrants the same caution. Article 20 states that an employer cannot prohibit secondary employment outside the work schedule, unless this is permitted by law. A contractual provision does not constitute legal permission. A strict reading of the text therefore leads to Article 6 of the Employment Contracts Act: a clause that imposes a duty of consent on the employee increases the employee’s obligations and is void.
The Brussels Court avoids that conclusion by interpreting the clause not as a prohibition but as a control mechanism, and by justifying that mechanism on the grounds of job safety. This is defensible when the position genuinely requires it: someone working with electrical equipment in a pharmaceutical setting should not be allowed to work at another job site at night while exhausted. However, the ruling does not give a free pass to the standard clause found in many model contracts that subjects any secondary employment to prior consent, regardless of the position. For an office worker, such justification is lacking, and in that case, Article 20 prevails. An employer who wishes to retain such a clause should explicitly link it to the safety risks or conflicts of interest associated with the specific position.
Where IT Law Comes Into Play: Know-How, Data, and Customer Contacts
For companies in the digital economy, the duty of loyalty is rarely the only tool at their disposal. Anyone planning to launch a competing business often does so using what they learn from their employer: the customer list, pricing strategies, source code, and product structure. That material falls under the trade secret law under Book XI of the Code of Economic Law and under the prohibition on unfair market practices between businesses, and, following the employee’s departure, also under a valid competition clause. As we discussed earlier in our blog post about a former employee who takes source code to a competitor, these measures result in cease-and-desist orders and penalty payments, separate from the sanctions under labor law.
This interplay is important for the presentation of evidence. Case law regarding preparatory acts permits an employee to establish a company and gather information, but not to use his employer’s data for that purpose. Exporting the customer database to a private address does not in itself constitute an act of unfair competition, but it does violate the duty of loyalty and may also violate trade secret law. Incidentally, the Antwerp Labor Court warned in 2020 that employers are not free to do whatever they want when gathering such evidence: in that case, requesting emails from a third-party company that the employee had contacted constituted an invasion of privacy (Antwerp Labor Court, June 24, 2020, Soc.Chron. 2022, 332). As we also saw in our blog post about Personal Use of Social Media and Dismissal for Cause, labor courts rigorously scrutinize evidence from digital sources.
Specifically, what does this mean?
For the employer. Don’t wait for damage to occur before taking action; instead, gather evidence of the act of unfair competition itself: a quote, an order, a customer visit, or a social media post containing prices or terms and conditions. A business registration number, a domain name, or a company in the process of being formed are not sufficient. Be sure to observe the three-business-day deadline from the time you become aware of the facts. When gathering evidence, be mindful of the employee’s right to privacy. And review your exclusivity or non-solicitation clause: link it to the risks of the position, or it will not hold up against Article 20 of the 2022 Act. If you are unsure whether the facts in your case already constitute an act of unfair competition, that is the first thing we will investigate for you. For handling the matter under employment law, you can seek assistance from a lawyer specializing in labor law.
For employees who are planning to start their own business. You may incorporate a company, register a domain name, create a website under construction, gather information, and negotiate. You may not approach your employer’s clients, submit bids for similar projects, or present work done for your employer as your own. Do not use your employer’s materials, data, or files, even for activities that do not compete with your employer’s business. Request permission when your contract or employment policy requires it, and consider disclosing any potential conflict of interest.
For employees with a non-competing side job. The law is on your side, as long as your side job does not conflict with your work schedule and does not interfere with your performance for your employer. A blanket prohibition in your contract may be void; a requirement to obtain permission that is linked to the safety of your position may not be.
Frequently Asked Questions
Can an employee start their own business while working their current job?
Yes, provided that the side business does not compete with the employer and is conducted outside of work hours. Article 20 of the Act of October 7, 2022, prohibits employers from prohibiting employees from engaging in side work for other employers, except where permitted by law. Self-employment as a secondary occupation falls under the same freedom of employment. However, the duty of loyalty remains in effect: no use of company resources, no impairment of availability, and no conflict of interest.
Can I set up a competing company while my employment contract is still in effect?
Yes. In 2015, the Labor Court in Mons ruled that an employee may, during the term of his contract, establish a company, acquire a stake in a competitor, register a domain name, and gather information. These are preparatory acts. Only the actual act of competing is prohibited: approaching customers, submitting bids, and taking orders. Anyone who begins such activity before the end of their contract risks termination for cause and liability for damages.
Can my employer fire me for cause for a single visit to a competitor's location?
Yes. On September 26, 2025, the Brussels Labor Court ruled that a single visit to a potential client, during which the employee introduced himself as an account manager for a competitor, constitutes an act of unfair competition that justifies dismissal for cause. The fact that the employee was not being paid and was on sick leave did not alter this ruling. The employer is also not required to prove damages.
Is a clause that requires me to ask for permission to take on a second job valid?
That depends on your position. On August 26, 2025, the Brussels Labor Court upheld such a clause for an employee who worked with electrical equipment at pharmaceutical clients’ sites, because the employer was entitled to verify safety and the proper performance of the contract. For a position without such risks, a general obligation to consent conflicts with Article 20 of the Law of October 7, 2022, and with Article 6 of the Employment Contracts Act, which declares null and void any clauses that impose additional obligations on the employee.
Conclusion
In Belgium, an employee may prepare to start his or her own business during the term of the employment contract, but may not engage in competitive activity. Labor courts draw the line at the first act of competition: a visit to a client, a proposal, or a price quote. Preparing, establishing, and negotiating such a business remain permitted, as long as no resources or information belonging to the employer are used in the process. In principle, a non-competing side business is permitted, but a consent clause may be upheld if the nature of the employee’s position justifies it.
ICT Rechtswijzer is the knowledge platform of the Intellectual Property, IT Law, AI Law, Data Protection, and Media Law department at Everest Advocaten, led by Joris Deene, Esq. Our attorneys assist employers and employees in defining preparatory acts and acts of competition, in protecting customer data and know-how from a departing employee, and in drafting exclusivity and consent clauses that meet the requirements of the 2022 Act.
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