Which company should I use to book train tickets in Italy

You can book directly also with Trenitalia's competitor
Italotren. Italotren has high speed rail service between major cities only and their prices I have found are less than Trenitalia's https://www.italotreno.com/en

I have never had problems booking directly with Trenitalia or Italotren and never heard of Trenitalia not showing the full schedule for the trains they operate.

I have used both apps to book trips while on the go in Italy.
The Trenitalia site requires the Italian spelling of cities; many not familiar with Italian may find this problematic.

You also need to change the time of day on the Trenitalia website. It will default to the current time at your actual location, so you may inadvertently be requesting a schedule beginning in the afternoon or evening. Change the time to your preferred starting time of the day to see departures pertinent to you.

I’ve had greatest success with the Trainline app. They charge a very nominal fee above the fare of the train company itself, in a very easy-to-use app.

I've never really had issues with the Trenitalia website. They may occasionally have interface glitches like any large web heavy platform but nothing that would prevent me from using it. The biggest issue with the Trenitalia site is you need to use the Italian names for cities for the best results.

I have also heard people complain that Trenitalia doesn't have schedules for 6 months - or some future period - out or something while ItaliaRail does, but ItaliaRail can't know what Trenitalia doesn't know yet. They may offer train tickets for trains they assume will run since the schedules don't change that much but I don't consider that a feature.

Both Trenitalia and .Italo have apps that I would recommend using in country to check schedules, book tickets and track trains.

I generally treat third party sites for train and bus tickets the same way I treat third party sites for hotels. They are great for research and comparison but I almost always go to the actual source to make my final purchase.

My $.02, as long as the tickets work for you where and how you buy them is up to you,
=Tod

If I ride Trenitalia, I buy from Trenitalia. If I ride Italo, I buy from Italo.

No extra costs, no third party middelamn.

I usually buy via their respective apps and the tickets are stored in the app. I also take a screenshot of them just in case the app acts up while the conductor is inspecting tickets.

YMMV

We never know which train to book since we don't know when we will clear immigration and customs and arrive at the train station.

For our April trip, I booked the 4 of us with Trenitalia, pretty much as soon as the availability came online 4 months in advance of travel. All business or first class--they were only a few dollars more than 2nd class, so why not? Non-refundable for the deep discount. What I'm paying is in Euro but for dollars allowed for a 1.05:1 exchange rate.

Florence/Rome (1 hr, 35 min) $42.95/pp

Rome/Salerno (2 hrs, 6 min) $37.70/pp

Salerno/Taormina (Sicily) (5 hrs, 45 min) $36.12/pp (includes ferry across Strait of Messina)

I have the Trenitalia app on my phone and a Trenitalia account as well. Have pdf's & QR codes of everything. Before travel, I will transfer tickets to my Apple wallet, and also will print out hard copies of everything as a failsafe.

I use the Trenitalia website and app on my phone and find it very user friendly. As was mentioned, you just need to use the Italian names for the stations, and a quick google search will give you that information. Just yesterday, I purchased second class "MeandYou" (discounted tickets for two traveling together) one-way tickets on the Trenitalia website from Roma Termini to Terontola-Cortona. They cost 23.60€ and cannot be modified, though I had the option to pay 2€ for a refund option.

I used the Man in Seat 61 website for information on seats and also noticed his recommendation for ItaliaRail. So for comparison, I looked up the same train on their website. The "MeandYou" tickets were not offered. The least expensive tickets (second class "Flexy)" cost $36 (about 35€ ) no changes, 90% refundable up to 48 hours before departure. There was also a $5 booking fee for a total of $41 or about 40€. The "MeandYou" option clearly made the difference in pricing and without it, costs and restrictions would have been similar, but something bothers me about emailing for a refund on the booking fee, but maybe that's just me.

I also like having the Trenitalia app on my phone for purchases at a station. If there are long lines at the ticket kiosks, you can just get your phone out and buy tickets that way. Very handy.

Hi, I’m planning my 9th & 10th trip to Italy, and I always use Trenitalia. It’s easy to use. If you’re purchasing the faster train options, the price is cheaper to buy the tickets ahead of time. Otherwise, if it’s regionale routes, the price stays the same. Using the Trenitalia app is easy, too, and saves waiting in line at the machines, especially in Rome!

I’ve used trains in Italy countless times during 13 trips there with never a problem.
I’d say I’ve taken nearly 80 or more journeys, long and short , on every type of train service offered.
As others have said, use the websites and apps for both Trenitalia and Italo, and buy direct from them.
If you have an IPad , the Trenit app is very useful to look at both companies on one app.
With the phone apps, you can check times and delays in real times.
If I know my schedule, I try to book cheaper tickets in advance if it’s a good saving.
Italian trains are efficient in my opinion.

Wow! I am so impressed with all the replies that I have received! You all have sold me on buying my tickets directly from Trenitalia or Italo.

geovagriffith, we won't be taking a train after arriving at the airport so I don't have to worry about figuring out which train to take. We will be flying in and out of Milan, and when we arrive in Milan, we are spending 3 nights there. This is a 5-week trip around central and northern Italy. So most of the time we are taking trains, and we will rent a car for Tuscany and the Italian Alps.

We don't have a lot of experience using trains, so that is why I wasn't sure what company is best for reserving and purchasing tickets. We used trains in Andalucia in 2017, and I think I purchased them from a 3rd party who eventually merged with Rail Europe. And then we took the train from Zagreb to Ljubljana in 2019. We purchased those tickets at the train station the day of because that train never gets sold out.

For Italy, however, I want to purchase our fast-train tickets in advance. We know what our itinerary is, and we don't normally change our itinerary mid-stream unless there are unforeseen circumstances, like this past fall when we were in Australia and New Zealand, and there were several road closures that necessitated changing our itinerary.

One more question, I hope. Is it possible to purchase tickets for regional trains in advance?

Thank you,
Karen

Yes it is possible to purchase regional Treknitalia tickets in advance but there is no advantage in doing so because the prices are the same and they don't sell out.

Buy from Trenitalia or Italo directly. Avoid middlemen. I’ve been taking trains in Italy for 25 years and have never had an issue buying online, even though 99% of the time we buy it the day of or right beforehand.

Thank you to CD in DC and to jonrossjan.
I appreciate everyone's help and advice.
Thanks,
Karen

I often use Trainline to buy rail tickets for travel in many places in Europe. They sell tickets for both Trenitalian and Italo, so that provides for "one stop shopping". Once registered on the site with a payment method specified, the process is very easy. They do charge a small fee, but I don't find that to be a problem. I've found their customer service to be very responsive.

I've never used Italia Rail but I believe they're similar to Trainline.

If using the slower Regionale trains, I often just buy tickets from a kiosk at the station. Note that locally purchased Regionale tickets have to be validated before use. Failure to do so may result in hefty fines, collected on the spot. Also, tickets for the express trains such as the Freccia high speed trains come with compulsory seat reservations, and are specific to train, date and departure time. Boarding the wrong train, even by mistake, may again result in hefty fines.

There's no advantage to purchasing Regionale tickets in advance, as the price is the same and no reservations are required.

Will you be travelling with a mobile phone and data plan? I often find that very helpful to check schedules and book tickets if necessary.