Depends on what train you intend to use-and this is very simple to check on most planning sites-it will tell so-yes or no-or optional.

In IT where you start it depends on type of train: the faster Frecce/IC need to, the slightly slower Regional not. As there are multiple trains/day if not even per hr, you can leave that till there and go to a counter. Moreorless same-same for Ams-Bru. Plus that you double up as Ams-LON also passes BRU. In fact in IT you also double up half the distance of MIL-FIR for to go ROM. Unless there is a specific reason for that-replan and shorten nr of trips!

This €* to/fro LON has to and you better do that asap-there are small quota for passes and for populair days these sell out weeks before. PLUS there is also a hefty surcharge of 30/35€-with some luck you can also find BUStrips on those sectors for same price. (FLIX or BlaBla).

All newcomers here get also a welcome from anna B Fra Sverige and she willlink to a long list by seewulf on howtodo RES by yourself for less and wit more choice.

thank you for your response.

What do you mean by IT? Is it closer to go to Florence from Milan? The reason for being is that, we will be staying a couple of days in one place.

Like we will be arriving in Milan but our first stopover is actually in Rome and so on and so forth.

We were just planning on doing like a day trip in Brussels from Amsterdam, hence it was a separate itinerary. Is it better just to get off in Brussels on our way to London?

When booking the ticket to and from London, are you saying to better reserve a seat? How do I do that with a Eurail Pass? And how would I know which trains are high speed, we are opting for shoerter travel time as we have kids with us.

Thank you very much for your response.

You must make a seat reservation for the Eurostar to/from London, see information below. 

There is a limited number of pass holder seats on the Eurostar and on popular departures and during high season those sell out weeks, and sometimes months in advance.

The best place to see the availability of passholder seats and make reservations on the Eurostar is 

https://www.b-europe.com/EN/Booking/Pass#TravelWish

Press "later trains" and eventually you will find the next available connection. 

If you have a mobile pass you need to generate a Pass Cover Number in order to make the reservation at b-europe. You do that here in the PCN generator:

https://community.eurail.com/news-and-announcements-39/pass-cover-number-generator-is-live-5653

Every country has it’s specific name for High(er) Speed Trains.

• Italy: Frecciarossa, Frecciargento, Frecciabianca (often abbreviated as “FR”)
• France: TGV (Inoui, Lyria, Ouigo,...)
• International Traffic to the UK is Eurostar; to Belgium, the Netherlands, and some cities in Germany = Thalys
• Germany = ICE
• …

IT = Italy.

A day trip Brussels is doable from Amsterdam, try to avoid Thalys. Best not try to squeeze it in when you’re travelling to London as you need qa lot of time for the passport and secutaintment checks when travelling to London. Otherwise you only get to see the clichés in Brussels, while it has a lot of nice museums too worth visiting.

        Milan → Rome = Fastest route is by Freccia-trains, reservation needed.

        Rome→ Florence → Pisa → Rome = Partly by Freccia-trains, reservation needed for some trains

        Rome → Milan → Freccia-trains, reservation needed.

        Milan → Venice → Milan, by Freccia, reservation needed.

        Amsterdam →  Brussels → Amsterdam = If you take the hourly IC Brussels Amsterdam, no reservation needed. (You cannot take Thalys, unless you make a very expensive seat reservation. It’s not worth it between Brussels and Amsterdam).

       Amsterdam → London = Eurostar, reservation needed. Make these asap.

       London → Paris = Eurostar, reservation needed, Make these asap.

When are you travelling?

Best take a look into this topic to get seat reservations for your aforementioned connections, without a booking fee

Hi. Thank you so much, this is really helpful.  We will be travelling this coming 3rd week of April until 3rd week of May