DmfA - online service

Before you start

What is DmfA?

DmfA stands for Multifunctional declaration (‘Déclaration multifonctionnelle’ in French – ‘Multifunctionele aangifte’ in Dutch). With this declaration, employers submit the pay and work time data of their employees. These data are defined and grouped in such a way that all social security institutions can work with the same information. That is why this declaration is called multifunctional.

The DmfA declaration forms a whole with 2 other types of declarations, i.e. Dimona and DRS. The link between these 3 declarations is as follows:

  • Dimona, which stands for Immediate declaration (Déclaration immediate’ in French, ‘Onmiddellijke aangifte’ in Dutch) is the declaration by which the employer declares every entry and termination of employment of an employee, i.e. at the beginning or end of an employment relationship. Find more information on Dimona on the Social security enterprise portal (in French);
  • DmfA is the quarterly declaration of pay and work time data, i.e. as long as there is an employment relationship;
  • DRS, which stands for Declaration of social risks (‘Déclaration des risques sociaux’ in French, ‘Aangifte Sociale Risico’s’ or ‘ASR’ in Dutch), refers to the set of social risk declarations necessary to notify the social security authorities about events that affect an employee's social position. Find more information on DRS on the Social security enterprise portal (in French).

DmfA is a quarterly declaration filed at the end of each quarter. Look into the fundamentals of DmfA on the Social security enterprise portal (in French).

The DmfA can be filed by the employer or by an appointed mandatary.

Online service for declarations up to 49 employees

Use the DmfA online service for declarations concerning up to 49 employees. Get access by clicking on the button Introduce a declaration (‘Introduire une déclaration’ in French) or Modify a declaration (‘Modifier une déclaration’ in French) on the DmfA page of the Social security enterprise portal (in French).

Batch declaration for large workforces

Most mandataries or employers having a large workforce work with a file transfer (FTP or SFTP). Look into the principles of this batch processing on the Social security enterprise portal (in French).

There are 2 types of declarations within the DmfA: next to submitting an original declaration, employers can make modifications to these declarations.

The original DmfA declaration

Submit the original DmfA declaration after every quarter. It contains the pay and work time data of all employees over the past quarter. The declaration is used to calculate the social security contributions to the NSSO.

The original DmfA must be submitted no later than the last day of the month following the quarter in question. Find more information on the declaration and modification of DmfA on the Social security enterprise portal (in French).

Attention: in case you don’t submit your declaration on time, penalties will be imposed. There is a deadline for payment of the social contributions indicated in the original DmfA as well. Check the calendar on the Social security enterprise portal for more information on deadlines (in French).

Modifying a DmfA declaration

After the original DmfA has been submitted by the employer or his representative, corrections can be made using a modifying DmfA declaration. Find more information on modifying a DmfA declaration on the Social security enterprise portal (in French).

Consult the Social security enterprise portal for a demo version of the online service DmfA. It can be useful to make dummy declarations without actually submitting them. There is a demo version for original DmfAs as well as for modifying DmfAs on the Social security enterprise portal (in French).

Anyone can use these demo versions without a specific access procedure.

Access to the DmfA online service (for both original and modifying DmfAs) is secured, given the confidential nature of the data. Therefore, you must first register via the Social security enterprise portal (in French). You can subsequently log in with one of the methods displayed: eID, itsme or eIDAS. eIDAS is the European cross-border system allowing access to online services with authorised ID keys from a selection of EU countries. You find more information on the eIDAS Help page on the CSAM website.

If you make declarations using the DmfA online service, you have the option of receiving a provisional declaration (in PDF format) in your e-Box Enterprise – an electronic mailbox. After submitting your declaration, a final declaration (in PDF format) is sent to your e-Box Enterprise as well. Find more information on e-Box Enterprise on the Social security enterprise portal (in French).

If you make declarations using file transfer (FTP or SFTP), you will find feedback messages from the processing of your declarations (in XML format) via the batch processing channel you have set up. Find more information on feedback messages on the Social security portal (in French).

DmfA is a fairly complex declaration. Many employers choose to mandate an accredited social secretariat or a payroll services firm to submit their declarations to the NSSO. For more information, please read ‘Appointing a Social Secretariat or Payroll Services Firm’ at the bottom of the Declaring Employees in Belgium page.

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