Where does the 20min rule (where you can use any train) come from in German passenger rights?

Question

Where does the 20-minutes passenger rights rule come from? (In other words, the rule for free choice of train after 20 minutes delay expected at the end of your journey). This is a condition that can happen all the way before or during your journey. (And it can go away, if some train would be faster than expected, so make a proof/screenshot of it in any case.)

Anyway, at https://fahrgastrechte.info/ it says for everything except "significantly reduced" tickets, this rule applies. This most famously nowadays excludes the German Deutschlandticket only valid for regional trains and some similar tickets. But let's assume we have a valid ticket…

In the EU, however, this only seems to be mandatory from 60 minutes. This is what this quite nice EU passenger rights website says.

What applies, for example, to Flixtrain or similar, which do not participate in the Service Centre for passenger rights (so-called „Servicecenter Fahrgastrechte“)? Can you take a DB train from 20 minutes delay? Because they e.g. do not mention this 20min rule on their passenger rights page (here in English). I know this works when your train is cancelled and the last train today, but well… that is an extreme case where you would even have the right to get a taxi or any alternative transport (even with the Deutschlandticket AFAIK, contrary to what I mentioned before, that's again an exclusion).

Contrary to that the Deutsche Bahn mentions this in their Beförderungsbedingngen (got the version from 2023-11-13 (at A.9 „passenger rights”):

Muss vernünftigerweise davon ausgegangen werden, dass der Reisende aufgrund einer Verspätung, eines verpassten Anschlusses oder eines Zugausfalls am Zielbahnhof gemäß Beförderungsvertrag mindestens 20 Minuten verspätet ankommen wird, hat er, auch mit einer zuggebundenen Fahrkarte, gegenüber dem EVU, dass die verspätete oder ausgefallene Beförderung vertraglich schuldet, unverzüglich die Wahl zwischen (i) der Fortsetzung der Fahrt oder der Weiterreise mit geänderter Streckenführung bis zum Zielbahnhof bei nächster Gelegenheit oder (ii) der Fortsetzung der Fahrt oder der Weiterreise mit geänderter Streckenführung bis zum Zielbahnhof zu einem späteren Zeitpunkt. Er kann dabei auch den Zug einer höherwertigen Produktklasse benutzen. Die Benutzung eines reservierungspflichtigen Zuges oder eines Sonderzuges ist allerdings nicht gestattet.

The German Eisenbahnbundesamt also did not help and just provides a big link list to many many laws.

(Cross-posted here originating from a Mastodon toot.)

Answer 1

The rule comes from German law EVO — Eisenbahnverkehrs-Verordnung. To be specific, § 11 (1) 1 where it says:

Der Reisende kann die Fahrt zum vertragsgemäßen Zielort mit einem anderen Zug durchführen, sofern vernünftigerweise davon ausgegangen werden muss, dass der Reisende sonst mindestens 20 Minuten verspätet am Zielort ankommen wird.

This means, that also other companies like Flixtrain have to comply.

It also means, of course, that you cannot just board any other train — you have to buy a ticket first. This doesn't apply within the DB to make it easier and prevent them from paying themselves many, many times.

This specific rule doesn't apply to the Deutschlandticket, except for trains which arrive between 12am and 5am or if it's the last connection, however then only up to €120.

EDIT: I stand corrected. This answer was factually INCORRECT. The rule only applies to regional trains, not to long distance trains, like DB Fernverkehr or Flixtrain. DB Fernverkehr is accepting this reason voluntarily, probably to save money. If the other train is arriving with less than 60 minutes delay compared to the originally booked connection, they don't have to pay. And that happened to me many times so far.

Which means, that this rule comes from the Beförderungsbedingungen aka Terms of service from the DB and does NOT apply to Flixtrain.