For the best prices and guaranteed seating in Italy, you should book high-speed trains (Frecciarossa or Italo) as soon as your travel dates are confirmed, typically 3 to 4 months in advance. Italy uses a tiered pricing system similar to airlines; "Super Economy" and "Economy" tickets are limited and sell out quickly, leaving only the "Base" (full price) fares for last-minute buyers. Booking early can save you up to 60% on routes like Rome to Florence or Milan to Venice. In 2026, the Trenitalia and Italo apps are very user-friendly for mobile bookings. For Regional trains (Regionale), however, there is no need to book in advance. The price is fixed based on distance, and tickets do not sell out because there are no assigned seats. You can simply buy a regional ticket at the station kiosk or on the app five minutes before departure. Just remember that if you buy a physical regional ticket, you must validate it in the small green or yellow machines on the platform before boarding to avoid a heavy fine.