Westbahn First Class is now included for 1st class Passholders.
From 15 September 2026, holders of a valid First Class Interrail Pass including Austria and Germany (apart from German Rail Pass) can travel in Westbahn First Class without paying for an upgrade.
Please note that seat reservations in 1st class are still not possible without an upgrade. See this Westbahn page for more info: Interrail Eurail Pass » Buy Westbahn rail tickets | Trains to Germany & Austria