Does visual voicemail also work outside of Belgium?

Visual voicemail works within the EU, just as it works in Belgium. There are no extra costs for using visual voicemail within the EU: you use your bundle of mobile data to do so. More info on any costs can be found here.

Outside the EU, we block the use of mobile data by default to protect you from high costs. So if you can't find Wi-Fi for your visual voicemail, you can always opt for the advantageous Global Data Pass: that is a bundle of mobile data for use outside the EU.