Introduction
An employment contract is the basis of the working relationship between employer and employee. Precisely for this reason, it is essential that this agreement be drafted in a legally correct manner. In practice, however, many employment contracts turn out to contain errors that can have far-reaching consequences, both for employers and employees. This blog discusses the most common pitfalls and explains how to avoid them.
Probation period too long
A common mistake is to agree on a probationary period that violates the law. The rules are clear and mandatory in nature:
- An employment contract shorter than six months may not include a probationary period.
- For a contract of six months to two years, the maximum probationary period is one month.
- A probationary period of up to two months is allowed for an employment contract of indefinite duration or longer than two years.
If this is deviated from, for example by including too long a probationary period, the probationary period is legally invalid. This can lead to situations in which an employer thinks he has given legally valid notice, while the notice is not legally valid.
Wrong notice period
Including incorrect notice periods is also a common mistake. The legal notice period for employees is basically one month. If it is agreed in the employment contract that the employee must observe a longer notice period, the employer is required by law to use a double period.
If not properly arranged, this can lead to unforeseen costs or discussions about the validity of the termination. Checking contractual notice periods is therefore always advisable.
Declare collective bargaining agreement or personnel manual not applicable
Employment contracts sometimes fail to explicitly state the applicability of a collective bargaining agreement or personnel manual. If these documents are not declared applicable, chances are that provisions on, for example, working hours, wage increases or leave do not automatically apply.
As a result, employees may claim different or less favorable regulations, which can lead to legal conflicts. It is therefore important for employers to always clearly record whether and which collective bargaining agreement or internal regulations apply.
No early termination clause
Fixed-term employment contracts regularly forget to include an early termination clause. Without such a clause, the contract cannot in principle be terminated prematurely, unless both parties still agree on it.
The absence of this provision can be problematic when continuation of the employment contract is not desirable. A correctly included interim termination clause then provides the flexibility to terminate the contract early, subject to the notice period.
Invalid competition clause in temporary contracts
Since the introduction of the Work and Security Act in 2015, it is in principle not allowed to include a non-competition clause in a fixed-term employment contract. Only if the employer has a compelling business interest may it be deviated from.
Moreover, this interest must be motivated in writing and specifically in the contract. If this justification is lacking, the non-competition clause is null and void. Employers would do well to critically assess, when drafting the contract, whether there is such an interest that justifies a non-competition clause.
Employment contract not properly signed
A final but not insignificant mistake is not having the employment contract properly signed. If the contract is not returned (on time) signed by the employee, discussions may arise about the validity of certain clauses, such as a study expenses or competition clause.
In the worst case, an agreement turns out to be unenforceable. Therefore, it is always advisable to ensure that you have a properly signed copy of the employment contract prior to the start of employment.
Conclusion
Although drafting an employment contract may seem like a standard act, the legal risk of small mistakes is significant. An incorrect probationary period, incorrect notice period or an unsigned contract can have far-reaching consequences. It is therefore advisable to always draft employment contracts carefully and, where necessary, have them checked by an employment lawyer. This prevents conflicts afterwards and ensures clear agreements from the start.

This blog was written by mr. Stijn Blom, employment lawyer at Arbeidsadvocaat.nl B.V. Stijn has extensive experience in employment law and supports entrepreneurs and employees on a daily basis with a variety of employment law issues. From dismissal cases to drafting watertight contracts and regulations - with his practical and personal approach, he helps employers and employees move forward. Want to know more? Visit Stijn's page.
Arbeidsadvocaat.nl is happy to think with you if you have questions about employment contracts. Please feel free to contact us .
April 2025