I have Italian citizenship, and would like to know what documents do I need in order to be able to sign a rental contract in Brussels.
After doing some research on the Belgium's official work site, I found an article talking about foreigner who want to work in Belgium.
You need to take with you:
-The visa for your stay in Belgium.
-The work permission document from Belgium (which is called "permis de travail").
-Your driving license.
I'm an EU national as well, and I only needed my national ID card for the landlord to verify my identity. We used this model contract, which as you can see, only requires your name and address.
I also had to sign forms (in quadruplicate!) for transitioning the utility contracts, which asked for my residence registration number. I didn't have one at the time (the process can take a while), but the utility's call center assured me I didn't need to fill that in, and I didn't receive any complaints from them after submitting the documents.