Book early and save: No
Booking tickets for this journey by direct train from Zurich to Bratislava is an exception to how tickets can usually be booked for European train services.
The OBB ticket booking service, provided by Austria's national rail company (it provides the trains on this route) sells this journey online in the conventional manner.
Meaning that you can search for the journey, see the price and then proceed to book it, should you wish to do so.
However, because both Zurich AND Bratislava are outside of Austria, OBB DOESN'T offer its usual discounted 'Sparschiene' tickets, between these two destinations.
Hence if you want to take this direct train, the comparatively expensive price will be the same, irrespective of how far ahead you will be booking.
To book tickets on SBB you can submit a booking request on its ticketing service, but prior to doing so, you won't know the price of the journey.
The money saving option:
If you look up this journey on OBB, you will also see alternative options which involve taking a Railjet from Zurich to Wien - and then connecting there for another train on to Bratislava.
Those options with a change of train in Wien/Vienna can be more than 60% cheaper than taking this direct train from Zurich to Bratislava.
That's because OBB will offer its discounted 'Sparschiene' tickets on the train between Zurich and Wien.
Making the connection in Wien Hbf station should be comparatively straightforward and your ticket will be valid on any train on from Wien to Bratislava - though ,if you'll be heading to the city centre, take care to board a train heading for Bratislava hl.st. station and Bratislava-Petrzalka station.
Booking for this direct train:
Online bookings open: 180 days ahead of the travel date
This train is usually scheduled to depart from Zurich at 12:40, so target that departure time when looking up this journey..
Seat reservations:
Seat reservations aren't automatically assigned when booking tickets for journeys by Railjet trains.
So you will need to be proactive and add the seat reservation when booking with OBB. the step-by-step guide you can access below will show you how.
If you want the peace of mind of being able to remain in the same seat all the way from Zurich to Bratislava, you'll have to reserve, but they only cost €3 per seat.
Travelling with a rail pass:
You won't have to reserve on this journey if you will be travelling with an InterRail or Eurail pass.
However, if you want to be sure of remaining in the same seat for the duration of the journey, particularly in 2nd class, you will need to pay a €3 reservation fee prior to boarding.
Though don't book them at a station in Switzerland, if you do, you will have to pay an €11 booking fee.
To avoid this fee, you can book these reservations as 'seat only tickets' online on the OBB website; we show you how HERE.