Alle Firmen mit dem Anfangsbuchstaben I
- Ing. Göschl Bernhard Paul
- Ing. Götzendorfer Markus
- Ing. Günter Krupitza e.U.
- Ing. Günter Michael
- Ing. Günter Vida - Sanitär- und Heizungstechnik, Gasgeräteservice und Reparaturdienst
- Ing. Günther Baschinger GmbH
- Ing. Günther Hoffmann GmbH in Liqu.
- Ing. Günther Köchl - Sachverständigenbüro für Elektrotechnik
- Ing. Günther Sillke
- Ing. Günther Uitz Beteiligungsgesellschaft m.b.H.
- Ing. Günther Zechmeister e.U.
- Ing. Güttinger Paul
- Ing. H. Wiesner Gesellschaft m.b.H.
- Ing. Haan Herbert Leopold
- Ing. Haas Johann Wenzel
- Ing. Haas Peter
- Ing. Haas Philipp
- Ing. Haas Walter
- Ing. Haas Wolfgang Peter
- Ing. Haberl Georg Franz
- Ing. Haberl Harald
- Ing. Haberl Johannes
- Ing. Haberl Peter
- Ing. Haberle Christian
- Ing. Habersack Emmerich
- Ing. Habringer Jürgen
- Ing. Hacker Eduard
- Ing. Hackl Florian Andreas
- Ing. Haderer Gerald
- Ing. Hadinger Gerhard
- Ing. Hadinger Helmut
- Ing. Hadl Beteiligungs GmbH
- Ing. Hadrian Michael
- Ing. Hafner Manfred
- Ing. Hagelkruys Thomas Josef
- Ing. Hager Brigitte Daniela
- Ing. Hager Erwin
- Ing. Hager Josef
- Ing. Hager KG
- Ing. Hager Veronika
- Ing. Hagg Stefan
- Ing. Haggenmüller Johann
- Ing. Haghofer-Vorholzer Birgit Michaela
- Ing. Hagl Stefan Michael
- Ing. Hagn Julia Elisabeth
- Ing. Hahn Michael-Johannes
- Ing. Haider Egon Alexander
- Ing. Haider Michael
- Ing. Haider-Punz Gudrun
- Ing. Haiderer Gerald
- Ing. Haidinger Johannes
- Ing. Hainbucher Franz Josef
- Ing. Haindl Herbert Erich
- Ing. Haizinger Lukas
- Ing. Hajdic Roland
- Ing. Halbartschlager Anton
- Ing. Haller Helmut
- Ing. Haller Jana
- Ing. Halper Patrick
- Ing. Halper Stefan
- Ing. Hameter Michael Helmut
- Ing. Hammer Stefan
- Ing. Hammer Werner
- Ing. Hammerl Bernhard
- Ing. Hammerschmied Johannes
- Ing. Hanke Georg
- Ing. Hannes Federer - Kfz Federer
- Ing. Hannes Obkircher Projekt GmbH
- Ing. Hans & Helmut Bodner OG
- Ing. Hans Bodner Baugesellschaft m.b.H.
- Ing. Hans Brantner Holding GmbH
- Ing. Hans Diettrich
- Ing. Hans Drascher GmbH
- Ing. Hans Haugeneder
- Ing. Hans Kern Verwaltungs GmbH
- Ing. Hans Leitner Versicherungsmakler GmbH
- Ing. Hansal Eva Maria
- Ing. Hansel Sven
- Ing. Hanzl Andreas Martin
- Ing. Harald Glösl e.U.