More and more employees combine their job with other activities: a side job, their own business, freelance assignments, volunteer work, or a board position. In employment law, these activities are referred to as ancillary activities (nevenwerkzaamheden). A question that regularly arises is whether an employer may prohibit, restrict, or make ancillary activities subject to prior consent. Since 1 August 2022, the legal framework for assessing this has been significantly tightened.
The key provision: Article 7:653a of the Dutch Civil Code
The central provision is Article 7:653a of the Dutch Civil Code (Burgerlijk Wetboek). This article was introduced on 1 August 2022 to implement Article 9 of Directive (EU) 2019/1152 on transparent and predictable working conditions, which obliges member states to protect employees against unjustified restrictions on performing work for others alongside their main job.
The essence of Article 7:653a BW is that a clause by which the employer prohibits or restricts the employee from working for others outside their working hours is void, unless the clause can be justified on objective grounds. An ancillary activities clause is therefore not automatically valid simply because it was agreed in writing, but it is not automatically invalid either. What matters is whether the employer, at the moment it relies on the clause, can point to an objective justification for the specific restriction. This approach is illustrated, for example, in a ruling by the District Court of The Hague, in which an employee had entered into a second employment contract of up to sixteen hours per week alongside her full-time position. The subdistrict court ruled that this created a concrete risk of exceeding the Working Hours Act (Arbeidstijdenwet), and emphasized that the employee’s interests must also be weighed in that assessment (ECLI:NL:RBDHA:2024:21917).
A consent requirement also falls under the rule
A common misconception is that Article 7:653a BW only applies to an outright ban. A clause requiring the employee to obtain prior consent also falls within the scope of this article: such a clause can equally restrict the employee’s ability to work for others. This means an employer may not refuse consent at its own discretion. A refusal, too, must be based on an objective reason connected to the specific ancillary activities and the employee’s position. The Arnhem-Leeuwarden Court of Appeal recently summarized this principle concisely: “This type of clause also falls within the scope of Article 7:653a BW. IrisZorg may only refuse consent if there is an objective reason for doing so.” (ECLI:NL:GHARL:2026:3919)
A notification duty is legally different from a consent requirement. Under a notification duty, the employee only has to disclose the ancillary activities, after which the employer can assess whether there is reason to take action. Under a consent requirement, the authority to intervene in advance lies with the employer, although that authority is limited by the objective-grounds test. Neither a notification duty nor a consent requirement may be used to effectively create an outright ban.
Which objective reasons can justify a restriction?
The law does not contain an exhaustive list. Article 9 of Directive (EU) 2019/1152 mentions health and safety, protection of business confidentiality, the integrity of public services, and the avoidance of conflicts of interest as examples. In Dutch practice, the following grounds also frequently recur:
- the risk that the combined working hours lead to a breach of the Working Hours Act
- protection of trade secrets and competitively sensitive information
- preventing conflicts of interest, for example when working for a direct competitor
- safety risks related to fatigue or reduced alertness
- the integrity or independence of the position, particularly in government or supervisory roles
A mere reference to “business interests” or “competition” is not sufficient. The justification must be substantiated concretely: what risk exists specifically for this employee and these particular ancillary activities, and why is the chosen restriction suitable and necessary for addressing it. This requirement of individual substantiation was recently underlined by the District Court of Midden-Nederland, which held an ancillary activities clause void because the employer had not sufficiently explained what concrete risk arose for this specific employee and their particular activities (ECLI:NL:RBMNE:2024:6411).
The objective reason does not need to be stated in the clause itself
It is not required that the objective reason be fully spelled out in the clause at the time the employment contract is concluded. What is required is that the justification exists at the moment the employer actually relies on it, for example when refusing consent or addressing an employee about their ancillary activities. In practice, however, it is advisable to already state the underlying interests when drafting the clause: this creates clarity for the employee and prevents disputes when the clause is invoked.
Ancillary activities clause versus non-compete clause
An ancillary activities clause must be distinguished from a non-compete clause within the meaning of Article 7:653 BW. A non-compete clause applies to the period after the employment ends and is subject to its own, stricter test, including in principle a written-form requirement and, for fixed-term contracts, an additional obligation for the employer to state reasons. A restriction on competing activities during the employment, by contrast, is not a non-compete clause but an ancillary activities clause, and therefore falls under the framework of Article 7:653a BW. In practice, these two clauses are regularly confused, even though the applicable test differs substantially. The District Court of Zeeland-West-Brabant articulated this distinction clearly: “Insofar as the non-compete clause relates to the latter situation, in the subdistrict court’s view, it does not constitute a non-compete clause within the meaning of Article 7:653 BW, but a disguised ancillary activities clause.” (ECLI:NL:RBZWB:2026:5158)
Rights and obligations of the employee
In principle, an employee is free to decide, outside their working hours, whether and for whom they perform work. That principle is protected by Article 7:653a BW. In return for that right, the employee is obliged to comply with a valid notification duty or consent requirement and to provide accurate and complete information when reasonably necessary to assess the consequences for working hours, safety, confidentiality, or conflicts of interest. The directive underlying Article 7:653a BW also requires member states to protect employees against detrimental treatment for exercising their right to engage in ancillary activities. An employee who believes that consent was wrongly refused can bring the dispute before the subdistrict court.
Working hours and rest periods
An employer may take into account the employee’s total working time, including both the hours worked for the employer itself and the hours the employee works elsewhere or as a self-employed person. Ancillary activities must not result in a breach of the statutory rules on maximum working hours and minimum rest periods. Fatigue and the associated safety risks can therefore constitute an objective reason to restrict certain ancillary activities, particularly in positions involving heightened safety risks.
When do problems arise in practice?
An ancillary activities clause tends to cause problems in practice particularly when it prohibits all ancillary activities without distinction, when a consent requirement is applied in practice as an outright ban, or when a refusal is not substantiated with a concrete reason tailored to the individual employee. Unclear terminology also leads to disputes, for example when a clause that in fact restricts ancillary activities during employment is labelled and treated as a non-compete clause. A concretely formulated clause, with a clear procedure and a named interest to be protected, prevents most of these disputes.
Fixed-term and indefinite-term contracts
Article 7:653a BW does not distinguish between fixed-term and indefinite-term employment contracts: protection against an unjustified prohibition or an unjustified refusal applies in the same way in both cases, and also to, for example, temporary agency workers and on-call workers. The nature and duration of the position may play a role in determining whether an objective justification exists in a specific case, for example in a short-term project involving access to particularly confidential information. This does not change the statutory test itself: even for fixed-term contracts, the employer must be able to provide a concrete, individual justification.
Points of attention for employers
- consistently use the term ancillary activities clause and distinguish it from the non-compete clause
- make explicit whether it concerns a notification duty, a consent requirement, or an outright ban
- link every restriction to a concrete and verifiable interest
- assess requests for consent individually and record any refusal in writing, with substantive reasoning
- take into account the employee’s total working time and rest periods
- review existing employment contracts and staff handbooks against Article 7:653a BW
Points of attention for employees
- carefully read the ancillary activities clause in your employment contract
- report ancillary activities in good time whenever an obligation to do so exists
- provide complete information about the nature, scope, and hours of the ancillary activities
- ask for the concrete objective reason in case of a refusal
- keep in mind that confidentiality and good employee conduct continue to apply even if a clause turns out to be void
- seek legal advice before unilaterally ignoring a prohibition or refusal
Frequently asked questions about ancillary activities
Can my employer prohibit ancillary activities entirely?
No, not without further justification. A clause that prohibits or restricts ancillary activities outside working hours is void under Article 7:653a BW, unless the employer has an objective justification for it. An outright ban without concrete substantiation rarely holds up in practice.
Do I always need permission before taking on a side job?
That depends on what is stated in your employment contract or staff handbook. If a consent requirement is included, you must in principle comply with it. However, the employer may not refuse that consent at its own discretion: a refusal, too, must be based on an objective reason.
What is the difference between a notification duty and a consent requirement?
Under a notification duty, you only need to report ancillary activities, after which the employer can assess whether there is reason to take action. Under a consent requirement, you must obtain approval in advance before you may start the ancillary activities. Neither form may be used to effectively create an outright ban in practice.
What reasons may an employer give for refusing consent?
Think of the risk of breaching the Working Hours Act, protection of trade secrets, preventing conflicts of interest, safety risks due to fatigue, or the integrity of the position. The reason must be specifically connected to your particular ancillary activities and role; a general reference to “business interests” is not sufficient.
Does the objective reason need to be stated in the clause itself?
No. The reason does not need to be fully spelled out at the time the clause is agreed. However, the justification must exist at the moment the employer actually relies on it, for example in the event of a refusal or when addressing an employee about ancillary activities.
Is an ancillary activities clause the same as a non-compete clause?
No. A non-compete clause (Article 7:653 BW) applies to the period after employment ends and is subject to a stricter test. A restriction on activities during employment is an ancillary activities clause and falls under Article 7:653a BW. In practice, these clauses are regularly confused, even though the applicable test differs substantially.
Does this protection also apply to a fixed-term employment contract?
Yes. Article 7:653a BW does not distinguish between fixed-term and indefinite-term contracts, and also applies to temporary agency workers and on-call workers. The nature and duration of the position may play a role in determining whether an objective justification exists, but the test itself remains the same.
What can I do if I disagree with my employer’s refusal?
You can ask the employer to substantiate the concrete objective reason in writing. If you cannot reach agreement, you can bring the dispute before the subdistrict court, which will assess whether the refusal is based on a valid, individual justification.
May my employer take into account the hours I work elsewhere?
Yes. An employer may consider your total working time, including hours worked for another employer or as a self-employed person, in order to comply with the Working Hours Act and the associated rest periods.
What happens if an ancillary activities clause turns out to be void?
If the clause is void, the employer cannot derive any rights from it, for example, it cannot impose a penalty for breach of it. This does not affect general obligations such as confidentiality and good employee conduct, which continue to apply.
Conclusion
Since 1 August 2022, an employer may not simply prohibit ancillary activities or subject them to arbitrary consent. Both a ban and a consent requirement are only sustainable if the employer has a concrete, objective justification for it, regardless of whether the employment contract is for a fixed or indefinite term. For employers, it is worthwhile to formulate the ancillary activities clause precisely and to clearly distinguish it from the non-compete clause. For employees, the principle is that they are, in principle, free to engage in other activities alongside their job, subject to their confidentiality and information obligations.
Do you have questions as an employer about drafting or reviewing an ancillary activities clause, or have you, as an employee, been confronted with a prohibition or a refused request for consent? The employment law specialists at Law & More are happy to think through your specific situation with you.
