Which contributor here says they are optional?

Please provide links.

“Expert on Facebook says” could be anything from anybody.

Trenitalia mark these services as reservation mandatory in their timetables, I’m not sure where the ambiguity comes from.

A LONG time ago it was optional. but as this led to so many probs this has been abolished and replaced with the standard as for all normal tickets with RES only. And it is only 3€. As you likely know as regular best done in advance via oebb. Indeed on my last trip there (but that was Frecce) I found the control system on board is now to quickly scan the QRcodes-conductors apparently then get an extra message if they have to check more.

Confusion perhaps with these direct EC-trains to AT/DE-RES as such optional, but the supplmt of 10€ for in IT not.

IT-rail is NOT an official partner, it is in fact a single guy near BOS/US who acts as agent for things on IT treni for those USAers used to having such things handled by an ´expert´. There have also been several postings that he has ceased doing RES-only, since TrenIT changed again the system to do that and/or the commissions (the latter more likely). (This info from tripadvisor/forum-trains and seat61)

Where exactly are Trenitalia saying reservations are mandatory?

Reservation was optional before corona. They're listed as optional e.g. here:

https://www.interrail.eu/en/plan-your-trip/tips-and-tricks/trains-europe/trains-country/trains-italy

(Under “Reservations”). But information from Trenitalia would be better.

Trenitalia say in their online timetable for any intercity service that it can be reserved, e.g.:

That's the phrase they also use for RV services, where reservations are optional (and almost nobody has one). If Trenitalia indicate elsewhere that intercity trains have mandatory reservations, then that's conflicting information. It sure doesn't help that Trenitalia don't send the "compulsory reservation” attribute anymore for any of their trains (including the Frecce) in the timetables they send to the European Timetable Centre (MERITS), which IMO is a serious omission. That's the reason why many other timetable planners, such as DB and ÖBB, don't mention it.

I recently used 2 IC services without reservations: Naples - Potenza and Metaponto - Reggio Calabria. I didn’t book reservations because I could see on the Trenitalia website that these trains would be largely empty. We were checked 3 or 4 times in total by different conductors but only once we were asked for a reservation, by a trainee, who didn't ask any further when we said his colleague previously was fine with it.

Of course such an experience doesn't prove anything and it would be much better for Trenitalia to provide unambiguous information.

I tried to find more information in Trenitalia's general terms and conditions but didn't find anything useful so far.

This 

is quite an old and buried discussion but I think it was actually fruitful enough for several of us to hammer out a broadly consistent policy on this topic with the approval of Interrail moderators.

Of course (as in rvdborgt’s experience mentioned above) it will probably almost always be fine to travel on an IC without reservation, but as I understand it the legalistic position is something like the following:

• “Prenotabile” can be taken to mean “reservation required”, because apart from for Interrail passholders, it is never possible to obtain seat reservations in Italy separately to tickets (except for certain cross-border trains to Austria).
• However, there is a difference between trains with assigned reserved seating (le Frecce/IC), and trains with non-assigned reserved seating (some RE/RVs).
• Reservations for IC trains now must be made at all times of year.
• Obligatory reservations on RE and RV trains were only introduced during the pandemic to prevent overcrowding by controlling the total number of passengers on a train overall, and although this system seems to have remained in place since then, it is not necessarily very strongly enforced. But Interrail passholders have a total exemption to any reservation requirements on these trains, and can ride them without restriction.

Reservations are mandatory. When I used ICs in Italy last year they always checked the reservation… when you are in a station with gates, they even checked it sometimes at the gate (asking for destination).

years ago it was not mandatory (also not for nighttrains called Espresso (or smth like that, trains starting with E). I used such one from Bolzano to Napoli without a reservation but that was like 10 years ago. Now all Inter City Notte require a reservation.

I boarded once a FB between Milano and Verona without a reservation and had to pay 10€ for the reservation plus 8€ fee… maybe this increased since then.

and beside even if reservations would not be mandatory (what’s not the case), would you really like to move every few stops your seat on a 12 hour ride from Roma to Palermo? Because reservations are NOT displayed on Italian IC. 

That may be the case but Trenitalia are not really doing their best to give unambiguous information about that.

For the Frecce the policy is clear. I recently read that the going rate is now €22 in total for a missing reservation in a Frecce.

I'd advise reservations for longer journeys anyway. On the other hand, you can easily see reserved seats via the Trenitalia website and app.

Hi, the word prenotabile in Italian would be in English bookable, reservable. 

There are Tickets that can use Intercity trains without reservation, this are some regional abonnements like in Emiglia Romagna Region or other regions. People with this monthly cards can also use Intercity trains. But it looks like that after the Pandemic, this is not more possible and they have to reserve a seat for free before boarding. But like this summer it was possible to use IC trains for people with monthly card on Intercitys (without reservation) in Liguria Region due to works. 

This information about the optional reservation for Intercitys I think is up-to-date, because when Covid was the Interrail website says reservation compulsory. 

Thanks for this very useful detail, I didn’t know that! If IC seat reservations changed to ‘compulsory’ and then back to ‘bookable’ again, that certainly does sound like they really are optional.

As ever though, the difficulty is just how to obtain the kind of irrefutable proof that would satisfy a ticket conductor who earnestly believed they were obligatory. You’d really want some kind of printed written confirmation either from Trenitalia (good luck with that...) or Interrail, otherwise it would still be difficult to travel with complete confidence.

Obviously buying a €3 seat reservation is the easy way out of this dilemma, but I suppose it might be desirable to travel on ICs without one on certain routes if you wanted to be flexible with travel times.

Some interesting replies that demonstrate my confusion, but still only interpretations, not definitive.

Surely the only definitive answer would have to come from Interrail. who currently clearly state that for IC trains in Italy a reservation is required

.

Not on their overview page to train in Italy, there they say only optional!  

Trenitalia determine the conditions, so they'd have to give the definite answer. But I'm not holding my breath :/

Unfortunately, the rail planner app and the booking module on the Interrail website haven proven again and again to contain many errors, also in this respect, so I regard any information about the necessity of reservations provided by them as: "this might be the case”.

It is clear that nobody can give a definitive answer so I remain unconvinced that there is any other advice to give other than reservations for Italian IC trains are compulsory, until Interrail change their planner to the contrary.

Whether that is because Trenitalia give clarification to all or Interrail/Eurail does is irrelevant. 

Hi everyone! 

I have reported this issue to the right department. I will update you as soon as I get an answer. 

Have a lovely day! 

Always check official sources, in this case the Trenitalia conditions of transport:

I titolari di un Pass Global o One Country valido per l’Italia (Interail, Eurail, in formato cartaceo o mobile) per viaggiare sui treni del servizio nazionale (Frecciarossa, Frecciargento, Frecciabianca, Eurocity (per i percorsi interni italiani), Intercity, Intercity Notte e Freccialink, devono acquistare il biglietto Global Pass che include la prenotazione del posto obbligatoria, il cui importo è riportato al Punto 5 del Capitolo 4 – Listino dei prezzi.

So, the reservation IS indeed mandatory on Intercity trains. In fact, the official name of the reservation in this case is ”Biglietto Global Pass”.

Here are the prices:

(AV stands for Alta Velocita - this includes Frecciarossa and Frecciargento, and FB is Frecciabianca)

Ah, thanks for digging this up. I did try to find the information in exactly this document but probably used the wrong search words…

For any interested people, the document is here:

https://www.trenitalia.com/it/informazioni/condizioni_generaliditrasporto.html

It's under the heading “Parte II : Trasporto Nazionale”, click on the first link “Trasporto Nazionale”.

I would add, that Eurocitys of Trenitalia for national rides have the rules of Frecciabianca. 

Thanks to all for finally laying this to rest.