All long distance trains in/via/to/from France have limited seats for pass holders.

For tomorrow, there are 2 Eurostar Brussel - London left with available seats:

On Sunday for London - Paris, the choice seems to be:

For Paris - vannes on Sunday, the choice is:

I'd suggest to plan with these trains and use the ICE (no reservation needed) to get to Brussels. In the UK, no reservation needed either.

The Interrail booking module still has a problem with the 20€ reservations in France.

Several booking possibilities:

• Eurostar via Interrail website (+ 2€ booking fee per seat).
• TGV in France for 20€ currently doesn't work via Interrail.
• Everything via SNCF phone service: +33 1 84 94 3635 (press #85 for English); no booking fee, reservations are sent via email.
• Everything via NMBS/SNCB phone service (more expensive phone number), no booking fee, reservations are sent via email.
• Eurostar via NMBS/SNCB website: pass cover number needed, 4€ booking fee.
• TGV via (another) NMBS/SNCB website: pass cover number needed, 4€ booking fee.

Thank you very much for your reply! It helped me! Thanks!

I booked a trip and reservations for today Munich-London and it worked.

Now I am in the Eurostar :)

But for the return (sunday, 27th of March), Cambridge (UK) - Vannes (Fr), is there still a possibility to book? I dont find any. Seems like the Eurostar is fully booked? I tried your suggestions.

Is there any way I can get from Cambridge to Vannes on sunday? Google Maps etc suggests a lot of connections, but I dont find any possibility to reservate anything.

Thank you again

As I wrote, all long distance trains in/via/to/from France have limited seats for pass holders.

This of course includes Eurostar and they now have no seats for passholders left on 27 March. The first Eurostar with passholder seats is on 28 March leaving London at 9:31.

There's  still a possibility via Lille. Availability on Eurostar London - Lille Europe:

Then Lille - Vannes (with a change in Paris):

12:05 is from Lille Europe; 13:42 and 15:12 is from Lille Flandres. 13:26 to 13:42 for a change from Lille Europe to Lille Flandres is too short; that only works if you arrive exactly on time.

Book the Eurostar for Sunday today and preferably the rest too.

Thank you so much. I will book now. Which webpage is it?

Eurostar on Belgian railways website (4€ booking fee) or via Interrail (2€ booking fee).

TGV on (another) Belgian railways website (4€ booking fee).

It asks for “pass cover number” and I dont find that one. Everything I try is incorrect.

“Invalid passholder number”

And it says it is only available for paper pass.

ON the belgian railway webpage. On the interrail one, it doesnt show me the connection,

Check your private messages.

Thanks again for your help!

Everything worked out.

I thought interrail is much more spontaneous and inexpensive (didnt know how much reservations one needs), and it costed a lot of time to research possible travel routes, but in the end, i could realize my travel plans, thank you for your help.