American citizens do not need a visa when they travel to Belgium for business or for personal travel. The stay in the Schengen area should not exceed 90 days within a six month period. The American visitor will need to present a valid American passport (that does not expire before the end of the visit), proof of sufficient funds, and a return airline ticket.
The Schengen visa is valid for the following 24 European countries: Austria, Belgium, The Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain and Sweden. A Schengen visa issued by an Embassy or Consulate of the above countries allows the holder to travel freely in all of these countries.
Visas issued on or before December 20, 2007 by the new Schengen States (Latvia, Lithuania, Estonia, Hungary, Poland, The Czech Republic, Slovakia, Slovenia and Malta) are only valid for these nine new Schengen countries, not for the whole Schengen area.
A citizen of the United States of America who intends to reside in Belgium for a period longer than 90 days, or for a succession of periods totaling more than 90 days per six month period, must first obtain a temporary residency visa.
When the applicant seeks to engage in a professional activity on an independent basis, the required residency visa can only be issued upon the presentation of a professional card and supporting documents.
Read the complete commercial guide to Doing Business in Belgium