Train Tickets All The Way To Florence on OUI.sncf

I'm not positive about this, but I think buying a through ticket from a single source would give you some protection if there's enough of a delay on the French part of the route that you miss the connection in Turin. With two separate tickets, you might be stuck buying a full-price, last-minute replacement ticket in Turin if you miss the originally-booked train. Let's see what the experts say tomorrow.

I'd say acraven is correct, that is how it usually works.

I would trust acraven’s answer. She knows her travel stuff and I always get great advice from her.

that is correct, above.

another reason is that you will have your same seat reserved for the whole journey. If you split it you will almost certainly wind up in a different seat and probably a different coach. Pre covid that might be a relatively small problem; in pandemic days you may not enjoy shuffling through the train to your new perch with all your stuff. and your fellow travellers may not like it either. and if you get all the way and somebody has inadvertently pinched your seat you will have all that hassle. and your old seat may well have been sold to somebody boarding at Torino, so you can't stay there...

Get the through ticket...

I concur with all the comments above. Let me give an example. In 2019 we hat tickets from Luzern to Beaune with stops in Basel and Millhouse. Upon arriving at the station in Luzern we noticed our train to Basel had been canceled. Speaking to an attendant he put us on the next train available. This put us behind and we didn't get to Basel in time for the train we booked. The attendants in Basel put us on the next available train to Millhouse where we repeated the procedure. They were required to get us to our destination by some means since we purchased the tickets together. We did, however, lose all of our seat reservations since the trains we took were not the ones we had tickets for. This was very inconvenient but we made it to Beaune.

Okay, great! I will book both trains (OUI and Trenitalia) through OUI. Appreciate the feedback!

You are actually changing trains in Torino, which Nigel probably did not notice in making his answer. It used to be that the Western Europe high-speed trains cooperated (in case of delays) even when you bought the tickets separately, which you often had to do. OUI web site did not in years past sell the connecting train within Italy, but if they now can, then you might as well keep it simple.