did you try to reserve on oebb.at and followed the manual? The reservation for nighttrains works a bit different for Railpassuer as the reservation for daytrains

Don use the seat only option when reserving a Nighttrain via oebb.at

Hi
I have done these steps but I get the information that no tickets are available. Does that mean that the train is full, no chance to get a couchette? 

Mikael

Possibly. But we can only check if you share your travel date.

The most common error is that people use the "seat only” option but that does not work for night trains.

Could “Not Available from interrail.eu” mean that it is not at all possible to book true my interrail pass? So i will have to buy the ticket? I try to book London to Newcastle on july 4 and always get this answer. Thank you for the reply

Trains in GB can't be booked via Interrail (or any railways company outside GB) because RDG didn't think it would be useful for them to stay connected to other railway companies.

You can book reservations however free of charge at a GB ticket office or online via GWR, see these steps.

Day trains in GB have optional reservations, regardless of what the rail planner app or the Interrail website claims.

Thank you, i don’t want to make reservation especially but do i understand that i can not book via interrail for travelling by train in the UK? So i have to pay my tickets once there? Or can i get tickets true a local ticket office in the UK, by showing my interrail-pass? Thanks again

Correct.

No, your pass is your ticket. GB seat reservations are free of charge.

You can book reservations online or at a GB ticket office, both free of charge.

Thank you, i will not make any reservations but if i can use my pass as free ticket everything is fine. All best Ben