Is it necessary to make seat reservations?

Hello!
Could you please help me?
I am going to Switzerlandthis July, I’m planning to arrive at Zurichairport and to take a train to Interlakenimmediately, that very day. I’ve read that in Switzerland reservations are notobligatory but recommended for Intercity trains during high season. So, shall Imake reservations for the trains Zurich – Bern, Bern – Interlaken? If I have aSwiss pass but no reservation does that mean that, in case the train is full, Iwon’t be able to board it at all? Or does that mean I’ll board it anyway but Ijust won’t have a seat?
Thank you very much in advance.

Hi Olena,

You don't need reservations for 99% of all trains. For some you can optionally book seats in advance but I would not recommend that to be more flexible. If trains are really busy you can still board but indeed you won't have a seat. More details are here.

Arno said: Hi Olena,
You don't need reservations for 99% of all trains. For some you can optionally book seats in advance but I would not recommend that to be more flexible. If trains are really busy you can still board but indeed you won't have a seat. More details are here.

Thank you very much!