As you have seen there are many posts on travelling from France to Spain.

Interrailing falls into 2 sections - travelling quickly by express and long distance trains and travelling on regional and local trains for the adventures.

The key difference is the former usually has mandatory advance reservations (at a cost) whereas the latter is reservation free (or optional) so you just take your pass and go.

To get from France to Spain is difficult because there is only one viable express route and it has a very limited and busy TGV service with relatively few seats available for pass holders and high reservation fees.

Alternatively you can head for Marseilles then local trains to the border, and then a Spanish equivalent to Barcelona.

There are plenty of posts on how to get reservations for the SNCF/RENFE operated express but this is very short notice.

Also have you booked your train from the UK (Eurostar)? They are also on limited supply and again relatively high cost. 

Yes, we’ve booked the Eurostar to Lille but then it seems impossible to book seats on any trains anywhere in France with our passes…...bit of a joke really. I thought the whole idea was to book as you go along, free spirit and all that!!!!!

Many domestic trains in France should be available to book because they don't have limited pass holder seats. On international TGV from/to France, that's another story, thanks to ever so customer-friendly SNCF.

Firstly your pass is usable on almost all trains in France.

Free Spirit is OK but as train travel becomes busier across the whole of Europe the trains are getting busier, so many at peak times are reaching capacity, especially the new super high speed trains that are replacing flying. Several operators have introduced mandatory reservations for these trains for all passengers. The reservation is normally given with purchase. Obviously with a pass you need to get a separate booking for these trains, often with a charge.

If you want to be a free spirit then travel on the generally slower trains, or visit countries like Germany and Austria where reservations are optional - but be prepared to stand on the really busy ICE trains. It is a bit like the UK where peak trains from Scotland to London can be boarded without a reservation but only one carriage is guaranteed available for unreserved passengers - all the rest are likely to be reserved for at least part of the journey.

You can still turn up and make reservations in station but you need to allow a bit of extra time and be prepared with a plan B (and C) for alternatives if fully booked.

As mentioned above you should be able to travel south from Lille on any number of TGVs as SNCF allows pass holders to travel for 20 euros on any train not full, after the 10 euro pass holder quota is full. These quotas are like Ryanair prices, variable depending on how popular the train will be with full fare payers.

ESpana is by far #1 and closely followed by FRance as #2 for being very unfriendly to passholders. ES/RENFE as there nearly all trains MUST be RES and it also cannot be done online before.

FRance is different-also a bit different as Yorkie describes: its TGV-and some IC- racing over these costly built hi-speed lines have all mandatory RES-it cannot have standees. The many more local/regional TER-trains have not and cannot RES(with the odd exception to Normandie). To discourage that anyone sits all day in these costly trains they have developed this system-also to protect revenue.

It is perfectly possible-but not quick to travel slowly-slowly (even thats relative compared to Wales) via the whole country and reach the border/frontiere with ES (provided they have also finally ended the numerous strikes-after all this week is the EUR mobility-week, so thats a fitting tribute to how trains should work-or not) and then change to ES local trenes onward-from next week not all the way, as obras on the lineas make for autobuses the last part.

It is just that it seems that all newbees want to ride exactly those trains that are the hardest to get-as if someone has ordered them to go there and nowhere else.

I would have thought that anybody would realise that trains requiring mandatory reservations would, like an airline, only sell enough reservations to fill seats. My post was clear that it was for trains without mandatory reservations, like ICE trains, that if you turn up and go without a reservation you may well end up standing. This is applicable to those you can optionally reserve and those you can’t reserve.

Hello! Thank you for your question. Could you please let me know which trains and for which dates you are trying to book?

Please take into consideration that some high-speed trains in France have limited seat allotment for Pass holders. Therefore, we advise our customers to book those as early in advance as possible to avoid disappointment. Most French high-speed trains and night trains can be reserved up to 2 months in advance.
https://www.interrail.eu/en/plan-your-trip/reservations/reservations-france

As for Spain, please keep in mind that domestic trains can be booked only locally at the train station. The only way to make reservations for domestic and long-distance trains is directly at the ticket offices of local Long Distance stations (not commuter stations). Find a list of long-distance stations here:

https://www.eurail.com/content/dam/pdfs/Reservations%20in%20Spain%20-%20stations.pdf

You can make reservations on the day of travel or up to 3 months in advance. It is also possible to pre-reserve a seat by phone, by calling +34 91 232 03 20 (Renfe phone sales). Please make sure to check this page for more details:

https://www.eurail.com/en/get-inspired/top-destinations/spain-train

For Paris-Barcelona you can try to request your reservations over the phone: 0033 18494

Finally, please keep in mind that some trains from Paris to Barcelona offer paper ticket reservations which need to be delivered to you or to your hotel address in Europe. Please be kindly advised that someone needs to sign upon delivery!

Last but not least, please be kindly reminded that you need to be logged in and have selected your created trip and travellers to use the reservations self service system. 

https://www.eurail.com/en/book-reservations

I hope the above helps!

Best regards,

Annie

@Annie. That is not correct. There are more possibilities, listed here:

This is not correct either. It is not the train that offers paper reservations. It's Interrail that has not implemented electronic delivery. SNCF offer reservations via email, as you can see in the list here: