From Brussels Airport Zaventem
When you arrive in Brussels, stop queuing for a taxi!
If you are travelling with hand luggage, call us once you are out of the plane. A Taxis Verts driver will be waiting for you within 10 minutes with a sign on your name at the press shop Le Relay (in front of custom exit)
If you have checked in baggage, wait until they appear on the luggage trolley and give us a quick call. Once again, a driver will be waiting for you within 10 minutes with a sign board on your name in front of the press shop Le Relay.
Furthermore, from both the airport and the city of Brussels, Taxis Verts has no Round Trip discount policy. It means that your “Go” and “Return” trips are already discounted. No constraints to take the same cab company for your return journey, to finally, get your discount on both trips.
See here the arrival time of your flight to Brussels Airport