Upgrading German Train Tickets
 

Hi European experts,

As part of a 2-legged 1st Class Germany to Austria train journey I've booked on OBB's website, I was placed onto a RB regional train for the German part.

As I will like to guarantee seating, will it be possible for me to upgrade my RB ticket to a IC one?

Tried to search for information on this but was not successful.

Thank you in advanced for any advice!

What is the route? And what is the price of an IC/ICE ticket by itself? Trying to change your ticket may be more hassle than it’s worth.

For 2A1C, I paid EUR215 for:

Munich HBf - Kustein (German RB)
Kustein - Landeck (Austrian RJX)

Tried pricing Munich HBf - Kustein on an IC on bahn.de and it comes up to EUR 109 for 3pax.

Wanted to see if I can upgrade my current RB tickets to IC ones?

Can I pay for a just seat reservations on bahn.de now and upgrade my the tickets at Munich station on the day of travel?

Thanks!