Purchasing train tix using stp

Where are you going that you need to buy tickets? If it is in Switzerland, you just get on the train and show your pass when the conductor comes by. Is this for a special train like the Glacier Express that requires seat reservations?

And if you bought the STP, you do not want to activate it until you get to Switzerland.

you pass is your ticket. So for any service that you pass covers you just get on board, and show your pass when requested by a ticket inspector.

For mountain railways and cable cars that are not covered by your pass, but where you get a reduction you just buy the ticket at the station. You can usually do that at any station. So if you for example wanted to visit the Jungfraujoch from Interlaken you can already buy the part that is not covered by your pass in Interlaken.

For some tourist trains you need a reservation, that often includes a surcharge. These you need to obtain separately. But there are only a handful of those trains.

Thank you WengenK for you reply, that was very helpful. You calmed our nerves!

Thanks Sam for your reply!