For most Trenitalia journeys, you should aim to arrive at the station 20 to 30 minutes before your scheduled departure. Unlike air travel, there is no formal "check-in" process for Italian trains; you simply find your platform and board. However, large stations like Roma Termini or Milano Centrale can be confusing and require significant walking time to reach the "binary" (platforms). If you are taking a high-speed Frecciarossa or Intercity train, your seat is reserved, so you just need to be on board before the doors close, which is typically one minute before departure. If you are using a paper regional ticket, you must allow time to validate it in the green or yellow machines on the platform; digital tickets on the app do not require this. If you need to purchase a ticket at the station, budget an extra 15 minutes for potential queues.