Access procedure

Access to the Filing application is through CSAM, the identification and access management portal for the Belgian government’s online services or through IDAAS. A valid digital key is required.


Users can choose between several types of digital keys:

A list of supported certificate authorities (CA) can be found on this page.

Login to FILING with a commercial certificate
New IDAAS solution starting 23/01/2024

As of 01/02/2024, authentication via CSAM with a commercial certificate to sign in to the FILING application will no longer be possible.

The technical teams at the Central Balance Sheet Office have therefore developed IDAAS (Identity As A Service), an alternative authentication solution that uses commercial certificates to file annual accounts through the above mentioned application.

Starting 23/01/2024, the IDAAS solution will be available in FILING, along with the authentication of commercial certificates via CSAM (which will remain accessible until 31/01/2024).

Practically, this means:

The new IDAAS authentication provides a new connection access, leading you to a new Personal Space.  The forms in the existing Personal Space associated with the CSAM connection are not accessible via the IDAAS connection.

Therefore, we invite customers to complete the forms currently pending no later than 31/01/2024 in the personal space linked to authentication with a commercial certificate through CSAM. Prompt payment of these filings will enable publication as soon as possible.

It is recommended to create an IDAAS profile with your commercial certificate and process all new forms in the new personal space from 23/01/2024.

As of 01/02/2024:

Only the IDAAS solution will remain available for filing via commercial certificates.

If you cannot find pending forms as of 01/02/2024, please contact our Contact Center at the email address [email protected], providing the following filing information:

- Enterprise number

- Closing date of the acounting period

- Model

- Deposit type (initial or correction)

- Language

- Name of the owner of the certificate

- Type of certificate


Use of the same key

Upload, follow-up and payment should always be done using the same digital key.

When a digital key is replaced or its period of validity extended, the key’s data may change. As a result, the certificate will no longer be recognised and the filing history may be lost.

In brief

  • How to log in to the Filing application: available in Dutch and French
  • How to set profile preferences: available in Dutch and French

Use of digital keys

 MORE INFO For more information on the use of digital keys, please see Procedure to access the Filing application.

First login

 NOTE When logging in via CSAM for the first time, new users must create a profile.

Electronic certificates

Please note that the FPS Policy and Support (BOSA) is currently preparing the Federal Authentication Service 2.0 (FAS 2.0), pursuant to which it will no longer be possible to log in to CSAM using a digital certificate from 01/02/2024.

The new access via IDAAS does allow authentication via commercial certificates since 23/01/2024.


What should I do if I am unable to log in?

Check that your electronic certificate (login identification) is valid and has been registered before opening the application.

To log in quickly and securely, always start by first clearing your web browser (Google Chrome, Mozilla Firefox or Microsoft Edge):

  • Clear the browsing history.
  • Clear the download history.
  • Delete cookies and other temporary files.
  • Clear the cache.

How do I delete my browsing history?

  • I use Google Chrome (available in Dutch and French).
  • I use Microsoft Edge (available in Dutch and French).
  • I use Mozilla Firefox/Mozilla Firefox for MacOS (available in Dutch and French).

Please note that antivirus software or endpoint protection could be installed on the end user’s system, meaning the certificate cannot reach the FAS because, for example, it is blocked by the HTTP headers. In this case, we advise requesting IT assistance to relax the security settings and then trying to log in again.

I see a white or grey screen or an error message when logging in. Is something wrong with the firewall settings?

If you see a blank grey screen when logging in and the following link appears in your browser, there is a problem with the firewall:

https: //

This problem is due to the firewall settings on your PC and can be resolved by allowing the following urls in your firewall:

There is also a firewall problem in case of the following error message "ERR_BAD_SSL_CLIENT_AUTH_CERT" or "ERR_EMPTY_RESPONSE".

Also in this case, you should contact your IT manager and additionally allow the following url in your firewall or that of your company in the list of Trusted Sites: