After completing grammar school in his hometown of Dornbirn, Rein went to the Handelsschule in Feldkirch.
In 1976, he passed the master's examination for plate tiler and in 1980 founded his own company in Dornbirn.
From 1980 to 1994, Rein was a member of the Dornbirn City Council for the Austrian People's Party.
[2] At the Landtag meeting on 10 December 2008, Rein resigned from office as provincial councilor and on the following day took his new position as President of the Federal Economic Chamber.
[3] He also served as chairman of the Vorarlberg branch of the ÖVP sub-organization Österreichische Wirtschaftsbund.