A probationary period clause is not valid in every employment contract

A probationary period clause is not valid in every employment contract: for contracts of six months or less, a probationary period is prohibited, and if the probationary period is too long or not recorded in writing, it lapses completely. An invalid probationary period clause means that you cannot simply let an employee go in the first few weeks, even though that is exactly what you, as an employer, were counting on. In this article, you will read when a probationary period is valid, how long it may last, and which pitfalls you must avoid as an entrepreneur.

What is a probationary period clause?

A probationary period clause is an agreement in the employment contract that allows both employer and employee to assess at the start of employment whether the collaboration is satisfactory. During the probationary period, both parties may terminate the employment contract with immediate effect, without a notice period, without a dismissal permit, and without the need for reasonable grounds for dismissal.

That broad termination option makes the probationary period clause a powerful instrument, but precisely for that reason, the law imposes strict conditions on it. If the clause does not meet those conditions, it is void: it applies as if a probationary period had never been agreed upon. An incorrect probationary period therefore offers no protection whatsoever.

When is a probationary period clause valid?

A probationary period clause is only valid if a number of strict requirements are met. The most important are:

• Agreed in writing. A verbally agreed probationary period is not valid. Always record the probationary period in writing in the employment contract itself.
• The same length for both parties. The probationary period must be of the same duration for both employer and employee. A deviating agreement renders the clause invalid.
• At the start of employment. The probationary period runs from the first working day. You cannot have it start later or restart it in the interim.
• Within the statutory maximum duration. If the agreed probationary period is longer than legally permitted, the entire probationary period lapses, not just the part that is too long.

The core issue: documenting it in writing is a requirement, but not sufficient. The duration and type of contract also determine whether the probationary period holds up.

How long can a probationary period last?

The maximum duration of the probationary period depends on the type and length of the employment contract. The main statutory rules are:

• Contract of 6 months or less: no probationary period allowed.
• Temporary contract longer than 6 months and shorter than 2 years: maximum 1 month probationary period.
• Temporary contract of 2 years or longer: maximum 2 months probationary period.
• Temporary contract without a fixed end date: maximum 1 month probationary period.
• Permanent contract: maximum 2 months probationary period.

If you agree on a longer probationary period than is permitted here, not only is the excess part invalid: the entire probationary period lapses. A probationary period of three months in a permanent contract therefore means no probationary period instead of two months. Please note: a collective labour agreement (CLA) may contain different rules for temporary contracts. Therefore, always check whether a CLA applies before setting the probationary period.

The iron probationary period: why an incorrect probationary period becomes invalid entirely

In employment law, the principle of the so-called "iron probationary period". This means that the rules regarding the probationary period are strictly applied and that there is little room for exceptions or retroactive rectification. If the clause is incorrect, you cannot subsequently rectify it or shorten it to the statutory maximum duration.

The common thread: the more carelessly the probationary period is set up, the greater the chance that it will be of absolutely no use to you at the decisive moment.

Practical examples of situations in which the probationary period is waived:

• The probationary period is stated only in a verbal agreement or in an email that is not part of the signed agreement.
• The agreed probationary period is longer than legally permitted.
• The probationary period applies only to the employee and not to the employer (or vice versa).

Probation period under a subsequent contract: note the exception

A common mistake is to agree on a probationary period for every new contract. In principle, this is not permitted. If an employee receives a new contract with the same employer (or with a successor employer, such as after an acquisition) following a temporary contract, a new probationary period is generally not allowed. The rationale is that you have already gotten to know each other during the initial period.

There is an important exception: if the employee takes on a position that clearly requires different skills or responsibilities, a new probationary period may be permitted under certain circumstances. That exception is interpreted strictly, so do not take it for granted.

The risks of an invalid probationary period for you as an entrepreneur

A probationary period clause feels like a safe trial period, but an invalid clause actually poses risks:

• False sense of security. You think you can let someone go, but the probationary period turns out to be invalid.
• No more voluntary dismissal. If the probationary period is waived, the standard dismissal rules apply: notice period, reasonable grounds, and possibly a transition payment.
• Continuous employment. A temporary contract without a valid probationary period simply continues until the end date if you cannot validly terminate it.
• Procedure and costs. An employee who invokes an invalid probationary period may claim continued payment of wages or compensation.

How do you set up a probationary period in a watertight manner?

A probationary period that holds up is a matter of due care. Pay attention to the following points:

1. Include the probationary period in writing in the agreement. Not in a separate email or a verbal promise, but in the signed contract.
2. Align the duration with the contract type. Check whether the contract is shorter than six months (in which case no probationary period is allowed) and adhere to the statutory maximums.
3. Make the probationary period reciprocal. The same duration for employer and employee.
4. Check any applicable collective labour agreement. A collective labour agreement may set different rules for temporary contracts.
5. Do not simply agree to a probationary period again in a subsequent contract. Only do so if the position is clearly different, and have this assessed if necessary.

Unsure about the wording? Have the employment contract reviewed by a specialist. A well-documented probationary period gives you the breathing room you need during the first few weeks, without facing any surprises.

Frequently asked questions about the probationary period clause

Am I allowed to agree on a probationary period for a six-month contract?

No. For an employment contract of six months or less, a probationary period is not legally permitted. If you agree to one anyway, it is void and the contract applies without a probationary period.

What happens if the agreed probationary period is too long?

In that case, the entire probationary period lapses, not just the part that is too long. A three-month probationary period in a permanent contract therefore means that there is no valid probationary period at all.

Must a probationary period be recorded in writing?

Yes. A verbally agreed probationary period is not valid. Stipulate the probationary period in the written, signed employment contract.

Can I agree to a new probationary period upon renewal?

As a rule, no. With a subsequent contract with the same or a successor employer, a new probationary period is usually not permitted, unless the employee is going to perform a position that clearly requires different skills or responsibilities.

Am I allowed to simply dismiss someone during the probationary period?

During a valid probationary period, you may terminate the employment contract with immediate effect without a notice period or dismissal permit. However, the reason must not be prohibited, such as discrimination; in that case, the dismissal may still be challenged.

Have your probationary period clause and employment contract checked

Do you want to be sure your probationary period holds up? MKB Juristen has extensive experience in drafting and reviewing employment contracts and the associated clauses. If you face an employment dispute, our employment law you move forward. Schedule a no-obligation intake and we will check together whether your employment contract is doing what it is supposed to do.