Guide · Dimona
Dimona late
or forgotten?
A late or missing Dimona is a level 4 offence under the Social Criminal Code. The administrative fine is € 3,000 to € 35,000 per employee concerned; if the labour prosecutor prosecutes, it becomes a criminal fine. If the declaration is missing altogether at an inspection, the NSSO also charges a solidarity contribution.
File the declaration today, with the real start date, and keep the proof. Below you will find what applies to each Dimona type and what to do now.
By Business Centrum editorial teamPublished
Updated and figures checked on
- Administrative fine
- € 3,000 to € 35,000
- per employee, level 4
- Criminal fine
- € 6,000 to € 70,000
- per employee, if the labour prosecutor prosecutes; for a legal entity, € 30,000 to € 720,000
- Solidarity contribution
- min. € 3,674.09
- per employee without Dimona, on top of the fine
Deadlines per type
When is a Dimona late?
The Dimona IN must be filed by the moment the employee starts working. The time counts: a declaration in the afternoon for someone who started in the morning is late. For the Dimona OUT you have until the first working day after the contract ends. Students, flexi-jobbers and occasional workers have their own rules, and that is where most of the risk lies.
| Type | For whom | Deadline | If it is late |
|---|---|---|---|
| IN | Every employee, including type OTH | By the moment the employee starts working. The start date is the start of the contract, even if the first working day falls later. | Level 4 offence. If the declaration is missing at an inspection, the solidarity contribution follows. |
| OUT | Every employee without an end date in the IN | The first working day after the contract ends. In case of dismissal without notice: the working day after the termination. | Level 4 offence. Until the OUT is filed, the employee is still employed by you as far as social security is concerned. |
| STU | Students with a student employment contract | Before the start, per quarter, with the planned hours from the signed contract. | No reduced solidarity contribution for any of the hours in that declaration. You pay ordinary social security contributions. |
| FLX | Flexi-jobbers | Before the start, IN and OUT per quarter, at the earliest 1 month before the quarter. Oral contract: per day, with start and end time. | Without a timely Dimona FLX with an OK response, no flexi status: an ordinary employee with ordinary contributions. |
| EXT | Occasional workers in hospitality, agriculture and horticulture. Hospitality: at most 2 consecutive days with the same employer. | Per day, before the start, with start time and end time or a day block. | No contributions on the favourable flat rates. You pay on the actual wage. |
| O17 · S17 · T17 | Article 17 in the socio-cultural sector and sport | Before each engagement, per quarter, at the earliest 15 days before the quarter. | Level 4 offence. |
| End time | EXT and FLX per day | Stopped earlier: until midnight. Stopped later: within 8 hours after the planned end time, or until 08:00 if that end time was between 20:00 and midnight. | Level 4 offence. |
| Cancellation | Employee who does not show up | Until the end of the calendar day the declaration relates to. For a period of several days: until the end of the first day. | Level 4 offence. |
Start date later than declared
A start date that falls later than declared cannot be modified. You cancel the period and create a new one in time. An earlier start date can be reported as a modification, at the latest when the employee starts.
Where it goes wrong
The mistakes we see most often
Declaration after the first shift
The employee starts in the morning, the declaration follows in the afternoon. For the NSSO that is late, even if it happens on the same day.
Too few planned student hours
If you plan too few hours for a student, another employer can use up the quota in the meantime. For the hours you add later, you then lose the reduced contribution. Plan as accurately as possible.
The extra who stays one more day
An occasional worker in hospitality may work at most 2 consecutive days for you. If he stays longer, you cancel the EXT declarations and declare the whole period as an ordinary employee, from the first day.
A NOK for the flexi-jobber
A flexi-jobber may only start after a Dimona FLX with an OK response. That OK only confirms the conditions of the reference quarter, the rest remains your responsibility. If a NOK looks wrong, contact the NSSO before you cancel.
Contract extended, end date unchanged
If you gave an end date in the IN and the employee stays on a new contract, you adjust that end date at the latest on the first working day after the original end date. If you gave no end date, you need an OUT when the job ends.
Sanctions
What does a late Dimona cost?
Article 181 of the Social Criminal Code penalises the employer who does not file the Dimona on time. Whether the declaration is late or missing altogether makes no difference: both are a level 4 offence, the heaviest level. This applies to the IN, the OUT, a late cancellation and an end time not reported in time.
The labour prosecutor decides whether to prosecute. If he does not, the FPS Employment can impose an administrative fine. For offences committed since 1 February 2026, these are the amounts, surcharges included:
- Administrative fine
- € 3,000 to € 35,000
- Criminal fine, natural person
- € 6,000 to € 70,000
- Criminal fine, legal entity (such as a company)
- € 30,000 to € 720,000
- Prison sentence, for serious offences
- 6 months to 3 years
Per employee
Each fine is multiplied by the number of employees concerned, up to 100 times the maximum. 3 students without a Dimona means 3 fines.
Mitigation and suspension
With mitigating circumstances the fine can go below the minimum, but not lower than 40% of that minimum. If you received no level 2, 3 or 4 fine in the previous 5 years, the administration can grant a suspension. If you intentionally employed people without a declaration, the opposite applies: it is an aggravating factor. The administrative fine is then at least half of the maximum, € 17,500 per employee, the criminal fine for a natural person at least € 35,000, and the court can also impose a ban on operating or the closure of the business.
An administrative fine can still be imposed up to 10 years after the facts. An old oversight does not disappear on its own.
Art. 22quater
The solidarity contribution when there is no Dimona
If an inspector finds that there is no Dimona for an employee, he reports it to the NSSO. The NSSO then charges a solidarity contribution ex officio, based on article 22quater of the NSSO Act. It amounts to 3 times the basic contributions on the average minimum monthly income, with a minimum of € 3,674.09 per employee in 2026. It comes on top of the fine.
The NSSO deducts the contributions you did declare for the same employee. The amount is sent by registered letter and charged to the quarter in which the inspection found the work. You do not need to declare anything yourself.
Better late than never
The law ties the solidarity contribution to a finding that there is no Dimona. A late declaration remains an offence. But if it is there when the inspector arrives, then on the wording of the law there is no missing Dimona left to find.
Worked example
Saturday inspection: 3 people without Dimona
An inspector walks into a brasserie. 3 people are working and none of them has a Dimona: a permanent employee who started on Monday, a student and a flexi-jobber. This is how the bill adds up.
Administrative fine
3 × € 3,000 to 3 × € 35,000
€ 9,000 to € 105,000
With mitigating circumstances
floor 40% of the minimum
from € 3,600
Solidarity contribution
3 × at least € 3,674.09
from € 11,022.27
Student and flexi-jobber
no reduced contributions for hours without a timely Dimona
ordinary NSSO
The solidarity contribution drops by the contributions you still correctly declare for these people. Ordinary social security on the wages of the student and the flexi-jobber comes on top.
For the employee
What does it mean for your employee?
A forgotten Dimona does not only affect you. These are the questions employees and employers ask most often.
Workplace accident
Your employee remains protected: the insurer or Fedris compensates the victim. The bill can still end up with you. If an employee is not correctly insured, Fedris affiliates you ex officio and recovers everything it pays out, plus a flat-rate contribution. An accident on the first day without a Dimona also draws the inspection's attention immediately.
The presumption: full-time
The solidarity contribution is a flat rate: 3 times the basic contributions on the minimum monthly income. The law therefore assumes full-time employment. If it was materially impossible for the person to work full time, you have to show it with documents on the actual work. If you succeed, the contribution drops proportionally.
Social rights
As long as the work is not declared, the employee builds no social rights with it, such as unemployment benefits and pension. A late Dimona with a correct DmfA restores that for the declared period.
Knowingly working undeclared
An employee who works while knowing he is not declared risks a level 3 sanction himself: an administrative fine of € 1,000 to € 10,000. This is only possible if an official report was also drawn up against the employer. Someone who also received benefits is not covered by that fine: he risks other sanctions, such as repaying the benefits.
Late Dimona OUT
As long as the OUT is missing, the employee is still listed as employed by you in the staff register. The other social security institutions see that data, which can raise questions for a benefit claim or a new employer.
Forgotten Dimona
What do you do now?
Waiting does not make a forgotten Dimona better. This is how to correct it, in this order.
File the declaration today
Submit the Dimona IN right away, with the real start date of the contract and the right type. The NSSO records when you filed. The declaration stays late, but it exists.
Wrong data: cancel and redo
A start date later than declared or a wrong type is corrected by cancelling the period and creating it again. If an occasional worker in hospitality stays longer than allowed, you cancel the EXT and declare the whole period as OTH. If the joint committee changes, you file an OUT and a new IN.
Secure the proof
Keep the employment contract, the notification with the time of filing, the schedule and the hours worked. If something in the notification is wrong, you have 5 working days to contest it. With these documents you can later show mitigating circumstances, or that someone did not work full-time hours.
Align the DmfA
The contributions for the days worked remain due. If it concerned a student or a flexi-jobber with a late Dimona, you declare those hours at ordinary contributions.
At an inspection: be open
A social inspector may give a warning or a deadline to put things right. Show what you corrected and when. If an administrative fine still follows, you can submit a defence. If you received no level 2, 3 or 4 fine in the previous 5 years, a suspension is possible.
Check the insurance
Check that your workplace accident insurance covers the employee concerned, especially if something happened during the period without a Dimona.
How we prevent it
No more late Dimona
As a partner of Acerta, Business Centrum handles the HR administration of SMEs in transport, construction, hospitality and wholesale. The Dimona declaration is part of it by default, together with the checks that catch a late or wrong declaration before an inspector does.
You send a message, we file the declaration
A name, a start date and a job title are enough. The Dimona is in before the first minute of work, also for the student you call on Friday evening.
The right type
We choose OTH, STU, FLX or EXT based on the contract. If an occasional worker in hospitality stays longer than allowed, we convert the declaration right away.
Quota and flexi check
We track the 650 hours of your student jobs and check every quarter that your flexi-jobbers get an OK. What that status costs you is explained in the guide on the cost of a flexi-job.
The OUT on time
Whenever a contract ends, the OUT is filed at the latest on the next working day.
Dimona and DmfA match
Every quarter we compare the Dimona with the declaration in the payroll administration. We find the gap, not the inspection.
And if it already went wrong
Coming to us after a forgotten Dimona? We correct it, gather the proof and help with your defence. Get in touch and we will review your file.
Frequently asked questions
Questions about a late Dimona
Your question is not listed? Call or email us and we will look at your situation.
Free consultationSources
Every amount and deadline on this page was checked against these official sources, last consulted on .
- FOD WASO, Wijzigingen aan het Sociaal Strafwetboek vanaf 1 september 2026
- RSZ-wet (wet 27 juni 1969), artikel 22quater, Justel
- RSZ, administratieve instructies 2026/3, studenten
- RSZ, administratieve instructies 2026/3: Dimona voor flexi-jobwerknemer
- RSZ, administratieve instructies 2026/3: Dimona voor gelegenheidswerknemers
- RSZ, administratieve instructies 2026/3: Dimona voor socioculturele sector en sport
- RSZ, administratieve instructies 2026/3: Dimona, algemeen
- RSZ, administratieve instructies 2026/3: solidariteitsbijdrage voor nalatigheid van de Dimona-aangifte
- Sociaal Strafwetboek, art. 101/1 en art. 181 (Justel); opdeciemen FOD WASO 1 september 2026
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Late Dimona
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