Do high speed trains sell out from Naples to Florence? I can’t find a train on July 9? I thought I was trying to book too far in advance but it looks like they are sold out on that date? Could this be true?
I think what you are running into is a major rail construction project in Florence, a bridge replacement. Trenitalia is unsure of the project schedule requirements so is holding off on releasing these trains for sale at this time. No high speed trains for sale on this route July 6 to July 9.
They may show up a later date with replacement buses around the construction and into Florence SMN.
They never run out. There are several trains every hour, so at most, they run out of tickets in the standard class, so you have to buy a ticket in a more expensive class, or take the next train.
Regarding July there are several major work projects on the line. besides the replacement of an overpass in Florence, they are upgrading the rail traffic signaling system by installing the ERTMS (European Rail Traffic Management System) a standardized system intended to replace the various national system. That work is scheduled in June and July, so you might have run into that issue.
It's the bridge, RFI has recently updated the timetable of the planned works: https://i.postimg.cc/wjWtMtYd/Immagine-2026-04-14-205937.jpg Based on what happened in the past they'll open the bookings around June 14.
The ERMTS works were completed last Sunday: https://i.postimg.cc/4xGMydbt/Immagine-2026-04-14-210017bis.jpg All sections have been upgraded.