Where can I rebook on Sundays with Deutsche Bahn?
We travel to France frequently and have had the problem once or twice that we had to rebook our train to France due to train-related issues. Since seat reservations are mandatory, you can't just board another train. But how do you do that on a Sunday or outside of the opening hours of a DB travel center? It would be interesting to know.
You could simply buy a new reservation online or (probably) on DB-Automaten.
I would most likely expect you to pay the full new reservation fee. (at least if you don’t buy a ticket at the same time!) In the travel center, there might be a free reservation under certain circumstances. (In conclusion, the DB has advertised that a free reservation is issued together with the ticket if required.)
If the reserved train has failed, I could imagine that you can get a replacement reservation at the information (if the travel center is closed) or enter another train without reservation.
Online