Freelancer payment besides a full time job
I have a full-time job and I am non-EU but resident in Brussels for 4 years. Recently I received an offer to work besides my full-time job during weekends on an IT project as a freelancer. The company I am working as a freelancer is based in Germany. During 2017 I should earn more than 12k EUR from this freelancer activity. Now I am supposed to invoice the German company. Do I need to add on the invoice the German 19% tax (MwsT). How should I declare this income in Belgium. Do I need to register somewhere.
Thanks in advance!