anyone have information on how to make an online seat reservation for international train from germany to switzerland?
Unfortunately it is not possible via official DB or SBB website, neither company allows booking of international seat reservations online. With DB, in case of any international connection, online can be bought only combination ticket+reservation. If you really need the reservation (see below regarding that) you might try addressing booking inquiry to DB by email. Or alternatively you can try some agencies, either online or pretty sure there are some agencies (meaning real physical offices) at the place of your residence which might help.
Though are you sure you need it? The thing is that for any daytime train between Germany and Switzerland seat reservation isn't compulsory and really rarely trains are so full that you won't be able to find a free seat to take. Thus in most cases seat reservation are rather useless and, imho, most of the locals travel without seat reservation.
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