Upgrading your Swiss Travel Pass from 2nd Class to 1st Class is a straightforward process that can be done for a single journey or an entire day. To upgrade for a full day, you can purchase a "1-day Class Upgrade" for a flat fee (typically around CHF 50). This can be bought conveniently through the SBB Mobile app, at SBB ticket machines, or at any staffed railway station counter before you board the train. If you only wish to upgrade for a specific leg of your trip—for instance, to enjoy the panoramic views on a scenic train like the Bernina Express—you can buy a route-specific upgrade. The price for this is generally half the difference between the 2nd and 1st class fares for that specific route. When using the SBB app, you should select the "Half Fare" option for the ticket price to see the correct upgrade costs, as the Swiss Travel Pass essentially grants you the same status as a 2nd class ticket holder. It is vital to obtain the upgrade before boarding, as "on-board" upgrades are often subject to surcharges or may not be permitted on certain high-demand regional lines.