Most probably pass holder seats are sold out. They're very limited on the TGVs between Brussels and France.

What's your destination on that day?

I will be going to Lucca, italy. Either sunday the 16th of monday the 17th

So some advice :

You can't book that train on interrail.eu for a few months for an unknown reason. There is indeed a quota for passholders on that train (all TGVs from Belgium). Call SNCF or go to a SNCB ticket counter to ask.

Other options : mainly going via Germany (a lot cheaper), unfortunately due to engineering works around Cologne the journey takes an hour longer than usual -> too long frankly (departure 06:23, arrival in Lucca at 23:29).

You could also buy a regular ticket between Brussels and Lille-Europe for 19€ and then a seat reservation for Lille-Europe - Strasbourg (10€). I'd do that if the passholder quota has sold out. Afterwards it's easy :

- IC21 Basel SBB - Lugano 13:03 - 15:58

- RE Lugano - Milano Centrale 16:02 - 17:17

- IC Milano Centrale - Viareggio 18:05 - 21:58 3€ through ÖBB

- R Viareggio - Lucca 22:10 - 22:27

Of course it'll be a long day :)

It's bookable if you look further into the future, e.g. on 2 August. These trains are quite popular and the quota is relatively small.

Ah great, I guess it was fixed :)

Then the above solution still applies : 19€ + 10€

@thibcabe Thanks a lot for your help already. 

The first option, via Germany, does not show in my options. Another option through Germany does show (17/07 : 14:25- 13:23) , but the tickets for the night train are already sold out..

Wauw thanks a lot for elaborating on the second option. That sounds great.

I have 2 remaining questions:

1. The seat reservation brussels - lille-europe, I can buy with eurrail too I saw. Or is there a reason you recommend to buy a regular ticket? See picture

1. The timetable on the app is sometimes different than the one online. So my ‘saved’ journeys in the app do not correspond with the actual trains that I’ll take. Is that a problem? I do have activated the ‘train day’ with my interrail pass and have seat reservations. 

The trains exist, but you may have to direct the planner a bit, other wise it will only show the fastest options and not the slightly slower cheaper options. Use bahn.com, much more reliable for international planning.

The pass reservations for Brussels-Lille is €20 (+ €2 booking fee if you book via on interrail.eu) and a regular ticket is often available for €19.

You should never plan with the rail planner app because it's unreliable. Just use it to register your journeys. By the time you travel, the timetables will usually have updated, so you can add the correct trains.

The journey via Germany isn't easily shown because it takes longer + there are engineering works around Cologne so the correct times might not appear on Rail Planner at the moment.

Your screenshot would be for the first train of the day, at 06:35 then ? However you could buy a regular ticket for the 07:17 TGV on sncf-connect.com and then simply move seats through the train at Lille-Europe (no time lost). As rvdborgt said, it's a few € cheaper too. :)

Rail Planner or the website aren't good planners. Best use bahn.com or the companies websites.

If times are still wrong on the day, add the train to the app manually.

It is not a good idea to activate the pass in advance : once the validity period has started, you won't be able to cancel it.

Both thank you very very much!!! Very helpful! I booked the train from bruxelles to lille europe and from there to strasbourg etc. 

I will download the apps, thanks. 

Oh I already activated my travel days strarting from the 11th of july. I am leaving Valencia the 11th so that is my first travel day. Not sure if I can still undo it and if it’s necessary to. 

It's generally not a good idea to activate anything in advance: your pass, a travel day (on a flexipass) or an inbound/outbound journey. You never know what will happen and you can only cancel activation until 23:59 CET before validity starts. If something unexpected happens, e.g. you wake up ill, then it will be too late to cancel and you'll loose travel days.