Dimona: Belgium's Immediate Declaration of Employment

Onmiddellijke aangifte or Déclaration immédiate, filed by your employer

Dimona is how Belgian social security learns that you have started or stopped working for an employer. You do not file it yourself, but it affects your contributions, health insurance, benefit rights and, for students, the hours counter. Below you can see when it matters to you and why it is not a work permit or a contract.

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As written locally

Dimona

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Your job start and end, reported by the employer

What a Dimona records

How one electronic declaration links you to an employer in Belgian social security records.

Dimona (from Déclaration immédiate / Onmiddellijke aangifte) is the electronic declaration an employer must send to the National Social Security Office (RSZ / ONSS) to report the start and end of each employee's job. The data reaches other social security institutions and is used for contributions, benefits and the student-hours counter.

Every employer in Belgium must report each new job through Dimona at the latest when the work starts. The end of the job is reported at the latest on the first working day after the contract ends, and changes or cancellations are declared too. The information goes to the National Social Security Office (RSZ / ONSS) and is shared with other social security institutions, so a missing or wrong Dimona can affect your contributions, health insurance and benefit rights.

Almost all workers are covered, including people on short contracts. Students working on a student contract must be declared with the special type "STU" no later than the day they start; otherwise the reduced social security contribution for student work is lost. Flexi-jobs use their own type with daily start and end times. Some trainees, volunteers and a few other groups are exempt.

For students, Dimona feeds the Student@work counter, which shows how many of the 650 hours per calendar year at reduced contributions are left. The counter deducts hours already worked and hours an employer has reserved in Dimona, so ask an employer to correct an over-reservation. You can download a certificate from Student@work to show a new employer.

As a worker, you can check your recorded jobs, pay periods and days worked in mycareer.be using your eID or itsme. If a job is missing or the dates are wrong, ask the employer or its payroll provider to correct its declarations and keep their written reply.

Key takeaways

Employers declare the start of each job through Dimona at the latest when work starts.
The end of a job must be declared by the first working day after it ends.
Student jobs use the STU type, which protects the reduced contribution within the 650-hour yearly package.
Student@work shows remaining student hours, including hours reserved in Dimona.
A Dimona is not a work permit or a contract.

Starting a job, checking your record or counting student hours

When a Dimona matters to you as a worker

You rarely see a Dimona yourself, but it matters when you start any job, including student work, flexi-jobs and paid placements, and later when you check your career record or remaining student hours. The examples show how workers, students and small employers deal with it in practice.

You need to know about Dimona when you start any job, including a student job, flexi-job or paid placement, and when you check your career record, student hours or benefit rights. Asking the employer to confirm the Dimona before your first day helps you avoid undeclared work.

Example situations

A student taking a summer job asks the employer to confirm the STU declaration before the first shift, then checks the remaining hours in Student@work.
A worker notices in mycareer.be that a previous job ends two months too early and asks the former employer's payroll office to correct it.
A small business hiring its first employee arranges with its payroll provider to submit the Dimona before the start date.

What a Dimona does and does not prove

Not a work permit or a contract

Why a declared job gives no right to work and does not replace a written contract, and how reserved student hours show up.

A Dimona is neither a work permit nor an employment contract. It records that an employer has hired you; it does not give a non-EU national the right to work and does not replace a written contract. Student hours reserved in Dimona can reduce your visible balance before you have actually worked them.

Workplace vocabulary to browse after Dimona

More Belgian work and employment terms

Once you know what a Dimona is, these cards explain other Belgian terms from working life, including the documents, payments and institutions you may meet in a job. They share this broad area of life, so read each one on its own terms rather than as a sequence of steps.

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