Look at the HRB and GnR "Type of Register" on the advanced search of [0], and add keywords such as "IT", "net", "net" and similar. I'm not that well-versed in t

Look at the HRB and GnR "Type of Register" on the advanced search of [0], and add keywords such as "IT", "net", "net" and similar. I'm not that well-versed in these matters, so while I think there is some source you could find a list of these names and just run a regex on, I don't know where to get that list. Also consider mining the CN fields of server certificates on German IP ranges/all IPv4 addresses (it's just 2^32), and check their Impressum. There you can look for a string ending in " GmbH" and " AG" in a footer, to get the company name to use your regex on. The benefit there is that it should yield all companies that have a German website with HTTPS, and I'd take a lack of HTTPS for the company website or a website not reachable via a second level domain under the .de TLD as a red flag. Assume to require a small German introduction telling the recipient to forward the English part to an English speaking colleague, preferably in the IT department, because the risk of hitting someone who can't understand your English application is quite large. [0]: https://www.handelsregister.de/ https://www.handelsregister.de/