Reporting the end of an employment contract

When a Belgian employment contract ends, you as an employer need to:

  • immediately complete a Dimona OUT in the online service Dimona to report that your employee is leaving your employment.
  • provide the necessary information to the NSSO in the online service DmfA to enable the calculation of the remaining social security contributions.

A Dimona OUT means the ending of a working period. This means that it must be done at the latest on the first working day following the last day of the employment contract.

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 Dimona OUT. You also find information on Dimona on the Social security enterprise portal (in French).

  • a break in employment or an absence
  • a transition to part-time work

In these cases, the employment relationship between employer and employee continues to exist.

National Social Security Office (NSSO)

  • Address: Place Victor Horta, 11 - 1030 Brussels
  • Telephone: +32 (0)2 509 59 59
  • Website:

You can also get in touch via our Contact page.