Comment by atomflunder

I travel between Italy, Austria, Germany and Switzerland somewhat regularly, not rarely passing through 3 of the 4 countries for a given trip. I use the Austrian national railway‘s (ÖBB) app to book my tickets, I get a single QR code on my phone that is valid for all legs of my journey, gets scanned by the personnel of whatever country‘s railway company, and I‘m good. Never had any problems whatsoever.