This is in fact not correct. There are two unique identifiers for every german citizen, first the so called "Rentenversicherungsnummer" and the "Steueridentifikationsnummer". Both are assigned at birth.
The usage of the Rentenversicherungsnummer is strictly limited by law, basically to pension-related administration. It cannot be legally used for general purpose.
The Steuerindentifikationsnummer used to be strictly limited to tax purposes. Against original political promises the legislation has been changed 2 years ago, weakening the limitations. I am not familiar with the details.
That's "propaganda" by the ministery, not answering many questions. They only claim that all government administration will become digital, smooth, and much cheaper.
Is it allowed to use the Steuer-ID for non-government purposes?
An enacted law is not "propaganda", it's the law. You can ignore all the fluff around the factual statements if you like.
The number is only intended to be used by government entities. The law restricts usage to census and communication with government entities (as well as already established tax-related use).
The law is not. But the press release you linked just promised bright future without giving any somewhat nuanced information. Mentioning the number of 584 (whatever it was...) authorities might sound like detail. But it it's completely useless for a single citizen. These are authorities all over the country, no citizen will ever interact with most of them. What I wnat to know how far does it reach for a single resident and where are the limits. The press release does not take citizens into account at all, it's just poor, that's why I called it "propaganda".
(At the moment I am citizen, but not a resident so I have no Steuer-ID yet. But a) it might become a resident some day again and b) as a citizen I occasionally have interact with various authorities anyway. So on top of being interested what happens in Germany in general it might affect me personally.)
An increasing number of previosly public administrative functions have been privatized. Does that immediately mean that data exchange stops there?
The number mentioned is of services, not entities supplying them (there are far more as many are rendered on a local level). A typical citizen uses a few dozen of those although often only once a decade or so. The text probably doesn't go into detail as that is part of another set of legislation.
I can't think of a service like the ones on the list that has been privatized. The law as written would not extend to that but who knows what would be enacted in that case.
Anyway, this is all theory so far as they are still in the stage of drawing up a technical architecture.
Absolutely. Credit scoring is a shady business and as a person educated in Germany I think shady business should be kept away from government information as much as possible.
The Steuerindentifikationsnummer used to be strictly limited to tax purposes. Against original political promises the legislation has been changed 2 years ago, weakening the limitations. I am not familiar with the details.