Tickets for those trains are on sale but not yet for passholders on Interrail website. They use a different deadline.

Check back on interrail.eu 90 days before travel date. Don't worry these trains won't sell out so far in advance :)

The Germany - France TGV/ICE costs 18€ while the Paris - Barcelona TGV costs 35€. There are ways to save money but it'd take longer. Feel free to ask for advice.

You can also call SNCF to book (press #85 for English):

https://www.sncf-voyageurs.com/en/customer-service/contact-us/telephone/

@Mukhammad @Camilo. Why are these reservations not bookable via Interrail/Eurail, although they can be booked elsewhere? SNCF TGVs can often be booked more than 4 months in advance, sometimes up to 6.

Hi @rvdborgt 

I can see availability until the 15th of March 2024, so we would need to wait a couple of weeks more, so the data appears. 

Have a nice day!

@Camilo.

Trains Paris to Barcelona are currently bookable via Eurail/Interrail until the morning train of 20 March. It looks like the website enforces a strict 90 day advance booking window, and not a minute more, since the afternoon train on 20 March can't be booked yet.

However, SNCF have opened bookings until 22 May (except for a few weekend dates, I suppose because of engineering works). You can verify for yourself on www.sncf-connect.com:

So the data is there, it's just that Eurail/Interrail seem to wait until 90 days before departure to allow booking. Is that intentional? Why is that?

@rvdborgt Checking internally 

Lass alle Zugliebhaber mich hassen, aber um ehrlich zu sein, kannst du viel Geld sparen, wenn du fliegst. Der Flug von Barcelona nach Paris mit Vueling oder EasyJet kostet rund 70 Euro hin und zurück und dauert nur etwa 2 Stunden.

https://www.kiwi.com/, one way 40 euro.

Weitere Informationen zum Zugtransport zwischen Barcelona und Paris findest du hier: 

https://www.seat61.com/trains-and-routes/paris-to-barcelona-by-train.htm

@Roberta Frank ich denke jeder weiß wo man die Preise für Flüge vergleichen kann.

aus Unweltgründen wäre auf alle Fälle der Zug Bevorzuzugen und im Normalfall ist es mit interrail auch günstiger als ein Flug…