You can redeem the promotional code using the SBB Mobile app:
Select your desired connection.
Click on the red button ‘Tickets from CHF xx.xx’ to access the ticket options. There you will find bike space reservations under ‘More tickets and reservations’.
Tap ‘Redeem promotional code’, enter your code and the price will be reduced accordingly.
Now tap ‘Purchase ticket for CHF 0.00’ and your seat will be reserved.
Important:
You can only use the promotional code for bike space reservations for one person at a time.
For trains without compulsory reservations and for fully booked trains, the ‘Bike storage reservation’ option does not appear.