Reservations are required for IC trains and all other faster trains in Italy (AV, ES, ESCity, IC). The only trains that don't require reservations are the R trains (usually designated with an R or RV).

Enter Milan and Ventimiglia on this Trenitalia link. Select the IC train you want and click continue. On the next screen you will have a variety of fares you can choose. In the more fares box on the left side, select the drop down menu and select global pass. Seat reservations for IC trains are 3€.

http://www.fsitaliane.it/homepage_en.html

You might not want to waste a pass day on this train if you find a 9€ Mini Fare (discounted fare that would include your seat).

dated info may say that reservations are optional on Italian IC trains as until the past few years they were indeed optional and I often rode the slower IC trains rather than the speedy Eurostar Italia type high-speed trains that not only mandated an advance reservation but at that time were charging I believe 15 euros on top of using a day on the pass - those have been lowered to 10 euros - 3 euros for an IC train and have no fear of not being to easily make those reservations once in Italy at any station - trenitalia.com site has frustrated so so many Fodorites in the past as a plethora of posts here say - some will say the problems using that frickle site are in the past but recent posts say otherwise, though the situation appears to be much easier but some report lots and lots of frustrations - again you can easily make those reservations once in Italy.

kybourbon as usual have proven to be a font of great info on Italian trains and trenitalia.com - she/he will always help you out if you do have problems as he/she has done zillions of times before - so give it a try but if it balks just do it upon arrival.

Q- have does one actually get the reservation if you book online - you may have to retrieve it in some machine once there or is it a code or what?

Some great sites for loads of great info on European trains - www.seat61.com; www.budgeteuropetravel.com and www.ricksteves.com.

>>>Q- have does one actually get the reservation if you book online - you may have to retrieve it in some machine once there or is it a code or what?<<<

First you register on Trenitalia to create your account. If paying for tickets with credit cards, you need to notify your credit card you will be making an Italian online purchase so they don't block the sale. Supposedly, Trenitalia also has Paypal now also. You need to use either Visa or Mastercard and Trenitalia used to state you needed to use IE for your browser. You get an e-mail PNR (booking code). You present this on the train when asked for your ticket.

****If buying on-line, after checking on seat/s availability, the system will ask the customer for his/her user-id and password for authentication.
Then you will be asked for:
- identification information;
- the payment of the sum (through credit card, CartaFacile or Bancomat for Bankpass Web customers).
After payment, the system will provide the Booking Code (PNR) and the Booking Change Code (CP) along with the carriage number and seat number/s.
For on-line purchases, the system will send a confirmation e-mail with all information on the transaction.

TICKET ISSUING
The ticket issuing of Italian Eurostar, Intercity and Intercity Plus trains takes place on board the train. The staff on board will issue the Ticketless ticket without requiring payment after checking the PNR stated by the customer with their list of expected passengers.
Should the customer have lost or forgotten the PNR number but be able to provide proof of identity (using a valid piece of identification) that corresponds with the details on the list, the staff on board may decide that the conditions exist for the issuing of the ticket and thus proceed with the Ticketless issuing (without payment request).****

You only see two options for ticket delivery when you select global pass - Ticketless with payment receipt via email or Ticketless with payment receipt on board. The receipt on board might be texted to a cell phone (many Italians have their ticket info on their phones) so that might not be an option for someone in the US. You might see a mail option, but that is Europe only. I only see tickets needing to be retrieved at stations with self service kiosks for international trains.

OK, here is the current up to date situation:

1) IC trains in Italia are now all 'reservation compulsory'. Any IC ticket bought at www.fsitaliane.it will include the necessary reservation.

2) HOWEVER, one of the few 'improvements' I've seen for passholders is that last year (2011) Trenitalia REMOVED the requirement to make a reservation or pay any fee on IC trains if you have a railpass. In other words, if you have an InterRail or Eurail pass you do NOT have to make a reservation, you can just get on. The odd thing is, as all the seats are reserved but no reservation slips are used any more, you won't know which seats are free and may have to play musical chairs as people get on and claim reserved seats!

3) If you WANT to reserve a seat on an IC (no bad idea for a long trip) it costs 3 euros and you can do it online at www.fsitaliane.it by acting as if buying a ticket, and selecting 'Global Pass' when you get to the fares selection page, in a drop down list marked 'More fares'

Great news - I can once again hop on any IC train spontaneously with my Eurailpass and in first class I should always find seats, though may have to play musical chairs at times?

>>>2) HOWEVER, one of the few 'improvements' I've seen for passholders is that last year (2011) Trenitalia REMOVED the requirement to make a reservation or pay any fee on IC trains if you have a railpass.<<<

Do you have a link to that information on Trenitalia?

Try this: http://www.eurail.com/countries/italy/trains-italy

If you click 'reservations' and look for Intercity it now says reservations are recommended not required.

I should add that this was advised to me in a sales news item directly by Trenitalia (or maybe it was Rail Europe, one or the other) at the time they chamged it, I'm not just relying on one line on one website!

All the more reason for folks traveling significantly on the train in Italy to consider the first-class Italy railpass - in all my years of riding IC trains in first class with a pass I have always always found lots of empty seats in first class - so with a pass now, again like it was a few years ago, just hop any IC train anytime - taking a bit longer but much cheaper than paying 10 euros on high-speed trains and having to get the darned mandated seat reservation.

For example I once took an IC train between Florence and Venice-Mestre and just hopped on - the train only served the Florence-Rifredi station and Venice-Mestre stations but shuttle trains from the main stations in both Venice and Florence are frequent and you can just hop on those as well. I actually walked the few miles from Florecne to Rifredi station, following the new tram line so you can easily hop the train to Rifredi as well - Rifredi having trains stop there that do not go into the deadend and seriously congested Florence S M N or Santa Maria Novella (sp?) station.

Want flexibility just to hop on trains at will and traveling more than a few times then strongly consider the first class Italy railpass - first class also having immense benefits IME over 2nd class for the average traveler on the trip of a lifetime - a more relaxed journey - though second class is perfectly adequate to get you from point A to point B as well and with a railpass in 2nd class you can still hop on Ic trains - I guess always hop on even if full or not it seems.