A few months ago I was asked to implement several open-source libraries in PHP for one czech company called Asisteam. One of them was a simple connector to ARES API (Czech economic subjects registry). By calling this API endpoints you can get company details and/or validate whether some given company ID (IČO) really exists and correspond to some existing company known by Czech government and law. You can find the library on github and you’re very welcome to use it and make pull requests if you know of any enhancement or bug fix.