On the website for the Belgian eID, you can find some basic hints & tips to sign PDF documents with the Belgian identity card and the Acrobat reader application….
But there are other PDF applications than Acrobat Reader DC and the guide on the eID signing doesn’t detail the prerequisites in the signing manual to make it work.
Technical tip: the tech prerequisites and how to validate them are explained in the technical manual (over here: https://eid.belgium.be/nl/technische-documentatie#7389)
Acrobat Reader DC may be the most prominent PDF reader, it’s certainly not the only one and certainly not the most performant one.
Furthermore, the document signing in Acrobat Reader is pretty confusing as you must select the “Certificates” module and NOT “Fill & Sign”.
Difference between Authentication & Signing
When you, as verified user, want to put a digital signature on documents, this is called “signing”, confirming the document content.
In this circumstances, the “authentication” part is not relevant. Authentication is used to prove your identity.
For your information: the Belgian eID is NOT designed to provide encryption (which is the 3rd option to use a certificate). So you cannot use the BE eID for encryption of documents, sadly enough.
More info (NL, also EN version available): https://eid.belgium.be/nl/aanmelden-met-eid#7559 (EN, https://eid.belgium.be/en/log-eid#7559)
Prerequisites
Certificates in user certificate store
You need to have the user certificates installed on your user account on the local pc (actually the personal user certificate store) to make the document signing work in the applications.
If you haven’t used the eID certificates before, or in the case of a new computer, you’ll need to install the user certificates on your computer.
The easiest and official way to install them, is using the eID viewer application.
eID Software
Note on Language
The eID website is supporting NL, FR, DE and EN as language, I’ll only refer to NL and EN as main languages but FR and DE are supported too.
Download
Download and install the eID software from this source: https://eid.belgium.be/nl (for NL. Also available: EN, FR and DE).
It includes the eID middleware and the eID viewer we’ll use to read and install the eID certificaties on your computer (actually your user account).
Install
The manual to install the eID software is here:
(NL) https://eid.belgium.be/nl/hoe-installeer-ik-de-eid-software
(EN) https://eid.belgium.be/en/technical-documentation
Verifying the presence of the user certificates (Signing)
When you use the certificates and/or the eID software, the certificates should be installed in the user certificates store automatically, but that is not always the case, depending the configuration and security of your computer.
Technical hint: there is a “Certificate Propagation Service” troubleshooting article on the eID website that helps you: https://eid.belgium.be/nl/technische-documentatie#7256
To sign PDF documents with a certificate, most PDF readers will check for certificates in the user certificate store on the local computer, not directly from the card reader.
Steps
1. MMC
Via the Windows button, run the mmc (Microsoft Management Console), you’ll need to run it in elevated mode (so consent the UAC popup)
2. Add snap in : Certificates
Via menu “File”, “Add/Remove Snap-in”, add the “Certificates” snap in.
Choose “My User Account” (as the eID certificates are injected in your user account, not your computer or service account)
Finish and click ok.
3. Open the personal certificate store
In the “certificates – current user” > Personal > Certificates, check the list of certificates available.
You should see something like:

If ok, then you’re ready to sign documents, using eID.
If NOT, then you’ll need to add the certificates manually.
Manual installation of the eID certs
1. Insert your eID
Attach a supported card reader and insert your eID smart card.
2. open the eID viewer > Certificates tab

Right click the “Signature” certificate (you can do the same for the Authentication certificate. Select “Detailed Information”.
Then, click the “install certificate…” button:

Then run the default option steps: click next, next next … next… finish.
Import the certificate to the current user certificate store



Click Finish and you should be set to go for signing documents.
Signing PDF docs
Adobe Acrobat DC
This is explained on the eID website:
(NL) https://eid.belgium.be/nl/digitale-handtekeningen#7261
(EN) https://eid.belgium.be/en/digital-signatures#7261
IMPORTANT
Select the “Certificates” module and NOT “Fill & Sign”.
The “Fill and Sign” is used for graphical signatures, replacing the manual signing of paper copies, and eliminates the need of rescanning.
eID is a “qualified” and legally support signature.
If your counterpart (the other signing party) doesn’t require a qualified signature, this is a good alternative for eID (as there is some sensitive data like social security number, incl birthday and gender mentioned in the eID signature)
Foxit PDF
Open the PDF file you want to sign.
Verify the presence of the Signature certificate
It should be popping up from the certificate store, which we fixed earlier. (if not present, go back and fix it)

Signing a document
When the certificate is correctly installed, go to the “Protect” menu, then click the “Sign & certify” button in the ribbon.

Then drag an area to mark a signing area and choose the signature options.

Done!
References
Digitale handtekeningen:
(NL) https://eid.belgium.be/nl/digitale-handtekeningen
(EN) https://eid.belgium.be/en/digital-signatures
And also
Add or remove a digital signature in Office files: https://support.microsoft.com/en-us/office/add-or-remove-a-digital-signature-in-office-files-70d26dc9-be10-46f1-8efa-719c8b3f1a2d
Last update:2020-12-28