Declaring employees in Belgium

To enable a correct follow-up by the Belgian social security, employers must submit two types of declaration for their employees. The first one is the immediate declaration (Dimona), and the second one is a quarterly reporting of executed work and salaries (DmfA).

In order to declare an employee, you will need their Social Security Identification Number (SSIN). If an employee does not have a SSIN yet, you can request one for them using BelgianIDpro.

You are required to declare every new person you take on and every person leaving your employment to the NSSO. It is important that you submit this declaration correctly and on time: before an employee starts working for you, a so-called Dimona IN must be in place for them.

Dimona is used for any type of employment contract.

Dimona declarations are filed digitally, in the online service Dimona. There are two versions of the online service Dimona, a secured and a non-secured version. As an employer, you should use the secured version of Dimona in first instance. Only if this is not possible, for example due to technical reasons or if you haven’t yet received a username and password, you can use the non-secured version. Consult the manual on Dimona (secured version) or the manual on Dimona (non-secured version) for a step-by-step guide on how to use this online service. 
The manuals include the required guidance on how to declare a new employee (Dimona IN) and how to make a declaration for an employee leaving your employment (Dimona OUT). They also describe how to modify or cancel a declaration. You also find information on Dimona on the Social security enterprise portal (in French).

As an employer, you must declare the work done by and salaries paid to your employees every quarter in the multifunctional declaration DmfA. The information from the DmfA is sent to various Belgian social security institutions.

DmfA declarations are filed digitally in the online service DmfA. Consult the DmfA brochure for more information. You also find information on DmfA on the Social security enterprise portal (in French).

What is the DmfA for?

The DmfA’s main functions are:

  • to determine the amount of social security contributions employers and employees need to pay
  • to submit to the government in a one-off communication the salary and work information of all employees

DRS (Déclaration des Risques Sociaux) is a declaration of social risks. A social risk is an unexpected event that has an impact on the social situation of an employee. This event may be a dismissal, a temporary unemployment, a long-term illness, an accident at work…

As an employer, you need to declare these kind of social risks for your employees to the social security institutions. You do so using the secured online service for social risk declarations, DRS. Consult the DRS brochure for more information on how to access and use this online service. You also find information on DRS on the Social security enterprise portal (in French).

What is the purpose of the DRS?

Based on your declaration, the competent social security institutions can determine whether your employee is entitled to benefits. This may involve:

  • a benefit related to the allocation insurance and maternity insurance,
  • a benefit following an accident at work,
  • an unemployment benefit, income guarantee benefit or activation benefit.

When do you submit a DRS?

It depends on the situation when to submit a DRS. Some declarations have to be submitted at the moment the social risk occurs. Others are made monthly, for as long as the socially insured person fulfils the conditions to receive benefits. In certain cases a declaration is needed once the social risk ceases to exist.

Consult the Administrative instructions on DRS on the Social security enterprise portal (in French) to find out how to proceed for each type of DRS.

The Belgian social security system applies to:

  • employees who work on Belgian territory and whose employer is based in Belgium
  • employees who are attached to the Belgian registered office of a foreign company

These employees have to be declared in Dimona and DmfA, just as Belgian employees are.

The only exceptions are residents of countries with which Belgium has concluded an international treaty or a bilateral agreement stipulating that the Belgian system does not apply. A list of these countries can be found on the page Agreements of the website Coming2Belgium.

The Dimona and, in particular, the DmfA are closely linked to Belgian employment and social security legislation. Given the critical importance of filling them in correctly, the social security institutions provide comprehensive legal information. This information is regularly updated. It can be found on the Administrative instructions part of the social security portal (in French).

The declarations are outsourced by many employers to a social secretariat (accredited by the Minister of Social Affairs) or a payroll services firm. An accredited social secretariat is empowered to collect your social security contributions, while a payroll services firm is not.

To mandate a third party to submit declarations for you, use the secure online service Mahis (in French) on the Belgian social security portal. Consult the Mahis manual for a step-by-step guide on how to mandate a third party.

Social Security Contact Centre

  • Telephone: +32 (0)2 511 51 51

You can also get in touch via our Contact page.