On the following panorama trains seat reservations are mandatory: Glacier Express, Bernina Express, Gotthard Panorama Express, Palm Express and Furka Cogwheel Steam Railway.
On all other trains, reservations are not mandatory but often recommended. Seat reservations are subject to a charge. Seats can be reserved at www.sbb.ch, via the Rail Service 0900 300 300 (CHF1.19/min.) or directly at the ticket office.