Last updated on 27 October 2026

Undeclared work (zwart werk) is paid work on which the employer does not withhold or pay wage taxes and which stays off the payroll. If the Dutch Tax Administration finds an employee who is not on the payroll, the law presumes that the employee has been paid for at least six months (Article 30a Wage Tax Act 1964).

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Legal basis

An employer in the Netherlands must withhold wage tax and social security contributions and pay them to the Tax Administration (Belastingdienst). A new employee must also be registered before the first working day. This is called the first-day notification (eerstedagsmelding).

If an inspection shows that someone is missing from the payroll records, or the first-day notification was not made, Article 30a of the Wage Tax Act 1964 (Wet op de loonbelasting 1964) applies. The employee is presumed to have worked for at least six months before the inspection. For each pay period, the wage is presumed to be at least the current wage. The employer can rebut this with evidence.

Employees also have support in civil law. If you work for someone for pay for three consecutive months, either every week or for at least 20 hours a month, an employment contract is presumed (Article 7:610a Dutch Civil Code). Your working hours are presumed to equal the average of the previous three months (Article 7:610b Dutch Civil Code).

How it works in practice

The Tax Administration and the Netherlands Labour Authority (Nederlandse Arbeidsinspectie) carry out workplace inspections. After an inspection, the employer may receive an additional tax assessment covering six months of wage taxes, often with a penalty. The Labour Authority can also fine an employer who did not pay the statutory minimum wage.

The employee can claim unpaid wages before the subdistrict court (kantonrechter). That claim becomes time-barred after five years (Article 3:308 Dutch Civil Code). Because there is an employment contract, dismissal protection, holiday entitlement and sick pay also apply.

Common pitfalls

Working off the books while receiving benefits is risky. Deliberately withholding information about income from a benefits agency can be a criminal offence under Article 227b of the Dutch Criminal Code, with a maximum of four years in prison. The benefit usually has to be repaid as well.

Employers often underestimate the six-month presumption. Even if someone worked for only a week, the Tax Administration will calculate six months. Without schedules, payment records or statements, that is hard to rebut.

Employees often lack proof. Without payslips, you need messages, photos or witnesses to show that you worked and for how many hours. Keep that material from day one. Also look past the label: a client who calls you a freelancer may in fact be your employer.

Our employment lawyers assist employers and employees in matters involving undeclared work and unpaid wages.