vAT registration

Today, I switched from the exemption regime to the subject to VAT regime because of the new activities I am going to carry out. I acknowledge that I now have to charge VAT in principle, but I have a few questions to clarify whether this applies specifically in my case.

My question is: do I always have to charge vAT when invoicing my services to customers, who are mostly companies? Are there specific situations or exceptions where I do not have to charge vAT, for example depending on the customer type (within or outside Belgium, private versus business customers, or international transactions)?