Booking Trentalia online

If its a long distance train, it will contain a seat reservation, car No. and Seat No. train No. and date. No need to validate. If it is a regional train with an "ordinary" fare, you do need to validate, but as is often pointed out here, there is no need to buy these on line.

While you are not required to register on the Trenitalia site to book tickets, things go a lot more smoothly if you do. Before booking, notify your credit card provider that you will be making an international transaction. If you don't, a computer may block your card for suspected fraudulent use.

I booked my tickets from Milan to Verona (and then Venice) with Trentalia online. No problems. You get your "ticket" in an email. Just present a copy of the email to the ticket checker on the train and you're set. I found it nice to know my times/seats were available ahead of time.

Hi Marjie, We booked ahead of time with Trenitalia and were happy we did. Make sure you get the validation numbers in your email (I forget what they are maybe someone can help me remember this). Take those email tickets on the train with you and a conductor will come to inspect. Even thought you will not need to get your tickets "validated," before you get on the train, you will still need those very important numbers. Trenitalia may send you more than one email,so make sure you get the correct ones for the train. Also, it helps to also give a quick call to make sure they have you in their system. We loved the fast train. It was very clean and comfortable and efficient, not to mention the amazing scenery.
Buon viaggio! Ruth

From what I see, your tickets are pre-validated when you purchase them online. This includes the Regionale trains booked with a high-speed as well. I recently booked a trip from Assisi to Rome. The ticket from Assisi to Foligno was on a Reginale train. The ticket from Foligno to Rome was on a high-speed. The high-speed ticket had the usual PNR number and seat assignments. The Regionale ticket does not have a PNR number but it does have a 7-digit ticket code number. It also has information that tells you that the ticket is pre-validated. There are no seat assignments as this is not possible on the Regionale trains. Also, even though the ticket is pre-validated for a specific train, this Regionale ticket is actually good for 4 hours. Here's the language on my ticket. 2.Tickets 2.1. are nominative, personal and non-transferrable
2.2. are already validated and allows journeys to begin within 4hours from the date/time indicated on this receipt Note that these are the conditions for online purchases. You would still have to validate your ticket if you purchased the ticket there.