Rail (what else?) question

The only reason to buy ahead is if you want to get a Super Saver ticket which is only good for a specific train leaving at a specific time. Super Savers are available for purchase a month in advance and are usually 1/2 the price of a regular ticket. If you have a Half Fare Card you can get 1/2 off the Super Saver ticket.

How are you getting from Interlaken to Zermatt?

We are on guided hiking trip that starts in Interlaken and ends in Zermatt

My limited experience when taking the train from Interlaken to Bern is that if you have the SBB app and have figured out how to use it, you can buy your ticket on the app even after you get on the train, as long as you have the QR code ready to show when the conductor comes by.

For your arrival, look at buying a Saver Day Pass now. If this is for this summer, you should be able to get a Saver Day Pass now 52 CHF. The point-to-point ticket is 77 CHF, so that saves you 25 CHF. With SDP, you can take any train that day. Do the same for Zermatt to Montreux, which saves you 24 CHF.

Montreux to GVA is 37 CHF, so you can just buy that when you get there.

I just asked this as part of a longer post but as it applies, I'll ask here as well. I play to get a 1 month half fare card for our trip in June. Can I buy a half fare saver day pass now, even though I don't currently have an active half fare card? Is the half fare card necessary for PURCHASE of a half fare ticket or USE of a half fare ticket or BOTH?

Thank you!!

You do not need to have your Half Fare Card at the time you purchase tickets or passes using the Half-fare discount. Only necessary to have it at the time of use.