The closest thing to a current ‘official’ way to do this internationally is probably ISO 17442 Legal Entity Identifiers, originating in the financial services industry; part of this is even more directly relevant to you in that this includes a global list of registration authorities [1] which are maintained as an integral part of the LEI system (LEIs generally are very helpful in dealing with international company data, where they are registered, not least because they are very reliable, and explicitly freely-available data!). The nearest alternative (proprietary, but larger dataset ) are DUNS numbers.

[1] https://www.gleif.org/en/about-lei/code-lists/gleif-registra...