Adding trains to the Eurail app doesn’t book seats, it is just a way of recording which trains you use.

If you need or want seat reservations you must reserve them separately, usually for a fee which varies between train companies.

There are 3 types of trains regarding seat reservations:

1 Mandatory reservation: Mainly longer distance trains in certain countries, you MUST get a reservation for these, they nearly always require a reservation fee.

2 Non-reservation trains; these are mostly local and regional trains. Reservations are not possible for anyone, you just add to your app and take any seat on the train when you board

3 Non-Mandatory Reservation trains: these allow people to board and take any available un-reserved seat but you can also obtain a reservation to guarantee your seat. Seats have electronic or paper notices showing the reservations so non-reservation passengers can see which are free.

This link gives details on reservations for passholders across much of Europe

If you have further questions give details of which trains and what dates you are travelling.

Just a word about express trains in the UK. When reservable these are non-mandatory and there are usually a small number of seats on each train left unreserved, So you can always board the train and take an empty seat - if you can find one - otherwise you will be standing for a long time. On most LNER trains they keep coach C free, but on busy trains everybody heads for that and they often only allow access about 10 minutes before departure. There is always a stampede of unreserved passengers and on busy trains there will be very few spare seats elsewhere on the train.

Also many companies allow passengers to book as the train is travelling towards a station so you may end up playing musical chairs. You cannot rely on the above seat indicators, even at the first station as there is both a delay between reservations at the ticket office and the train indicators and people grabbing a last minute reservation for the seat you thought free.

As reservations are free I advise you to make a reservation for all UK trains - You can always check at the station as you can get reservations, if available, up to a few minutes before departure.

For Amsterdam - Switzerland you surely go via Germany so reservations are optional (except for ICE Germany - Netherlands this summer) but often recommended as those trains can be pretty busy. Do not book on eurail.com, there's an unnecessary 2€ booking fee per train

- 3€ per train on tickets.oebb.at OR

- 4.50€ per journey on bahn.de (the desirable options), no matter how many trains

Note that seat reservations are a complete waste of money and often can't be done anyway. Trains are plenty and have lots of capacity

You probably forgot to mention "in Switzerland” :)

Indeed, my bad...