There is a Firmenbuch in Austria which officially registers all businesses. Unfortunately, retrieving data from that register is not for free. Take a look here, and you will see a price list after your search query. (If you know German, there are more information about the Firmenbuch here at the Republic of Austria's Unternehmensserviceportal.)
If you are ...
the correct form of consulting data officers from API Open Corporates:
Base -> https://api.opencorporates.com/v0.4/companies/jurisdiction_code/company_number?api_token=Your_API_Token