Overnight train from Paris to Toulouse

Do not buy tickets from RailEurope. They will be more costly, and the company doesn't offer all the trains, as you have discovered.

Trainline.com is a legitimate company. It has just started charging a service fee (I think a modest one), so you'd probably save a bit of money by buying directly from SNCF, the French national railroad. I believe loco2.com also handles French rail tickets, and it does not assess a service charge.

Thank you!

On the French rail website, oui.sncf the train you want leaves from Paris Austerlitz at 22:08 and arrives in Toulouse at 6:01 am. Couchettes are available. As noted above, RS links to the reseller Rail Europe, which doesn’t offer all the trains available on SNCF. Rail Europe also doesn’t offer all the reduced price fares. oui.sncf is the official site.

By all means pay the slight premium for a first class (4-berth) couchette, you get a lot more space per person, making the journey more bearable. The few remaining French sleepers are quite basic compared to ones in neighboring countries.

Our Rail Europe link has that train ticket available from $50 in 1st class (bed in a 4-berth couchette), same as the 44 euros charged at oui.sncf. They don't currently have the lowest rate for 2nd class (bed in a 6-berth couchette). To see night trains, you have to to choose a later departure time, usually 10 p.m., at the same time that you choose your date.