Be aware: as of February 2026, fines for violations of Belgian social legislation will increase by 25%, due to a change in the ‘Opdeciemen’ applied. Additionally, the federal legislator is introducing extra measures for the most serious violations. Forewarned is forearmed.
Federal legislator taking a tougher stance
On 30 December 2025, the Act of 19 December 2025 was published in the Belgian Official Gazette. This Act implements the government agreement of the De Wever administration and aims to significantly strengthen the fight against social fraud and social dumping, which undermine social security, distort competition and endanger the safety and health of workers.
Increase of criminal fines
One of the measures put forward by this new legislation, is the de facto increase of criminal and administrative sanctions by 25%.
To align fines with price developments of recent years and preserve their deterrent effect, the legislator has increased the number of statutory surcharges (‘opdeciemen’) from 70 to 90. The system of ‘opdeciemen’ was introduced in the 1950s and intended to allow adjusting fines automatically in accordance with inflation, without being obligated to amend the entire (Social) Penal Code each time. ‘Opdeciemen’ are therefore a kind of multiplication coefficient. Currently, the system of ‘opdeciemen’ still applies to the Social Penal Code. In this respect, until now, the ‘opdeciemen’ are set at 70, but will rise to 90 as from February 2026. Consequently, the amount of the fines will need to be multiplied by a factor 10 instead of a factor 8.
Tightening of sanctions for serious social law offences
The Act also significantly tightens sanctions under the Social Criminal Code, in line with the government’s ambition to intensify the fight against social fraud and social dumping. For level 4 offences (the most serious offences) committed with an aggravating factor, the criminal or administrative fine may no longer be set below 50% of the statutory maximum amount. Aggravating factors include, among others, knowingly and intentionally committing the offence, or obstructing inspections through violence, threats or intimidation.
In practice, this leads to a very substantial increase in minimum fines, particularly for legal entities, for whom the minimum criminal fine for level 4 offences with an aggravating factor may now amount to EUR 360.000, with minimum administrative fines of EUR 17.500, in some cases to be multiplied by the number of employees involved.
Entry into force
The Act enters into force on 1 February 2026 and applies exclusively to offences committed from that date onwards. Earlier offences remain subject to the previous sanction regime.
From February 1, 2026, fines for violations of social legislation will increase. This is due to an increase in the so-called “opdecimes,” which will rise from 70 to 90. In addition, the federal legislator is introducing extra measures for the most serious violations.
Opdecimes
The opdecimes system was introduced in 1952 through the Opdecimes Fines Act, mainly with the intention of allowing fines to adjust automatically with price increases in society, without having to amend the entire Penal Code each time.
With the introduction of the new Penal Code, the situation has changed somewhat. For opdecimes, the amount of fines in the new Penal Code was established by setting the counter to zero, which means that the multiplication coefficient provided for in the Opdecimes Fines Act is now included in the provisions of the new Penal Code itself.
This is not the case for special laws, such as the Social Penal Code. Fines imposed by courts still need to be increased using the opdecimes specified in the Opdecimes Fines Act. Currently, opdecimes are set at 70, but from February 1, 2026, they will rise to 90. The federal legislator aims to ensure that fines retain their deterrent effect.
In practice, this means that fine amounts no longer need to be multiplied by a factor of 8 but by a factor of 10.
Stricter sanctions for the most serious violations
In addition to higher fines, stricter sanctions will be introduced for the most serious violations. These are violations that carry a level 4 sanction and are committed with a so-called “aggravating factor.”
The Social Penal Code provides for four sanction levels, each corresponding to the severity of the violation of social legislation. Level 1 is the lowest and applies, for example, to incorrect completion of social documents, while level 4 applies to offenses such as undeclared work and illegal employment.
An aggravating factor may arise when a level 4 violation is committed intentionally. It can also apply if obstructing an inspection (a violation that is already punishable with a level 4 sanction) involves physical or psychological violence or threats against the social inspector. The aggravating factor must be considered by the judge or administration when determining the sanction to be imposed.
When an aggravating factor is established, the administrative or criminal fine imposed from February 1, 2026, must be at least 50% of the maximum amount provided in the code. In practice, this means that a judge may not impose a criminal fine lower than EUR 3,500. The administrative fine must be at least EUR 1,750. Note! These amounts must be increased by the opdecimes. From February 1, 2026, this will therefore be EUR 35,000 and EUR 17,500, respectively.
There is an important nuance: if a violation was already intentional and this alone increased the sanction level to level 4, the 50% minimum fine is not applied again, thus avoiding double penal aggravation.
Effective date: February 1, 2026. The new rules apply to violations committed after the effective date.
For a deeper discussion on the above, please reach out to your Vialto Partners point of contact, or alternatively:
Philip Maertens
Partner
Nic Boydens
Partner
Bart Elias
Partner
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