Travel between Italy and Switzerland

1 what is the easiest way to take train from Milan to interlaken

You can use the same station that you will arrive in Milan to got to Interlaken
You can book that using this site
https://www.thetrainline.com/en/train-times/milan-to-interlaken-ost

2 train from Switzerland back to stresa

Take the train from Interlaken Ost to Stresa
You can book that using this site

https://www.thetrainline.com/en/train-times/interlaken-ost-to-stresa

3 any rail pass would be good to use in Switzerland or Italy

I think you should get one only for Switzerland. But it depends on how long you plan stay,

By my calculation you have 4 days after your husband’s conference. Do yourself a favor and eliminate the CT. It will be insanely crowded in July. Alternatively you could just give the 4 days to Venice and also eliminate Lake Como. There’s plenty to do and see, especially if you include some of the other towns of the Veneto; and you may have had enough of alpine lake scenery, gorgeous though it is. I hope you have made some reservations. If not, get cracking on it.

Count where you spend each night. If you arrive in Interlaken on the 6th, and then to Stresa on the 12th, That only gives you 5 full days in Switzerland. I would leave that to Interlaken and Luzern for those 5 days, and start by going to Luzern, since you can get a direct train there from Milano Centrale. 3 nights there, then 3 nights in Interlaken, but preferably Lauternrunnen, Wengen or Interlaken. Then you can get a train from there to Stresa via Spiez.
Stay in Stresa for 3 nights. Its on Lake Maggiore, then to Venice for 4 nights, then to Rome.

In Switzerland, if you get passes or Half Fare Cards, you can get a free Family Card and the 12 yo travels with you for free. In Italy, buy discount, nonrefundable tickets. They can also work for Milan to Luzern.

Thank you for all of your suggestion , that is very helpful
For the train ticket in Italy. Should I buy it online now in advance or wait

I agree with Sam. Stay in Stresa for 3 nights and enjoy Lago Maggiore. Skip Como this trip. The ferry system is great and fun to explore the area that way. Three nights is only two full days, Use 1 day to visit the Boromee Islands, and another to take the tram to Monterone, visit Baveno, or Verbania and Villa Taranto.

From Interlaken it’s an easy train ride to Stresa. Then train from there to Milan for your next destination.

You should book Italian train tickets as soon as you have finalized your itinerary and secured lodging reservations. That way, you will get the best price.

Swiss tickets are good for the day and always the same price, so no need to buy in advance. You will not have very much in the in the way of Swiss tickets for Arth-Goldau to Luzern to Lauterbrunnen say, to Domodossolo on the way to Stresa. Maybe 120 CHF worth, but you are bound to want to make some mountain excursions or lake boat trips in Switzerland which is likely to put you over 240 CHF per person tickets. So if you get Half Fare Cards at 120 CHF for 3 of you, you can get a free Family Card and the 12 yo travels with you for free. That will cut those 240 CHF fares in half to 120 CHF.

Since you are traveling on a Saturday, the direct Milan-Luzern train does not run that day. However there are several EC trains from Milan to Zurich, and you can take one of those and get off at Arth-Goldau or Rotkreuz and transfer to a train to Luzern. You can buy now Smart-2 fares for 39 EUR per person at trainline or loco2.

Wow this is more complicated than I thought . Can you please explain me more about the smart 2 ticket?

It is a discount, nonrefundable, train specific ticket on EC trains between Italy and Switzerland. Like an airline ticket. You will see it offered at https://www.trenitalia.com/en.html, or at the reseller websites www.loco2.com or www.thetrainline.com.

In Italy itself, the discount tickets for high speed trains are called Super Economy tickets at Trenitalia, or Smart tickets at Italotreno, https://www.italotreno.it/en, and also at the resellers mentioned previously.

Italotreno offers competing high speed service on the Rome-Milan, Milan-Venice, and Venice-Rome legs of the trip. They are often cheaper, just as nice (some say nicer), but less frequent than the Trenitalia Freccia trains.

Hi thanks again for your help. When I try to book a train ticket from Rome to Milan and Milan to Lucern. What type of ticket should I pick to make sure that 4 of us can sit together ?

And last question is how to buy the half fare card to use in Switzerland, can I just buy it when we are in Lucern?

When I try to book a train ticket from Rome to Milan and Milan to Lucern. What type of ticket should I pick to make sure that 4 of us can sit together ?

Just buy the cheapest ticket available (2nd class). The ticket type has no influence where you sit. The website will by default pick seats together.

how to buy the half fare card to use in Switzerland, can I just buy it when we are in Lucern?

You can buy it in Luzern. If you want to pay half price for the Swiss part of your Milan to Luzern trip, then you need to have the pass in your hand before you board that train. In which case buy it from the SBB website here: https://www.sbb.ch/en/leisure-holidays/travel-in-switzerland/international-guests/swiss-halffare-card.html
Whether you buy it from a station or online from SBB, it will cost the same (CHF 120).

If you buy tickets from Rome to Milan, on July 5, you will see the cheapest tickets are Super Economy, meaning they are train specific and nonrefundable, like airline tickets. You should be seated around a table, 4 seats together. I see they can be as low as 156.70 EUR total for the 8:30 am departure.

If you buy tickets only as far as Arth-Goldau on July 6, you will see the cheapest tickets are Smart 2, meaning they are train specific and nonrefundable, like airline tickets. Again, I see seating around tables together. Most departures on the EC trains at 156 EUR total.

At Arth-Goldau you can stop and buy Half fare cards for the 3 of you and the free Family card to cover the 12 yo, and continuing tickets to Luzern. There are trains to Luzern every 15 minutes, so no rush. Note that the ticket office at Arth-Goldau is open from 8 am to 4:15 pm, but closed for lunch from noon to 1 pm.

By my count, you have 18 nights, and 2 of those are already booked for your husband's conference? Also, a traveling day doesn't really count as a "being there" day. If you've never been before, it is tempting to see as much as possible. But if you want to enjoy the trip, I really suggest you follow Rick Steves' advice about packing: less is better.

In Rome, 5 days is minimum. I have been to Milan and, unless you are an opera fan and tickets are available at La Scala, it is totally, completely skip-able. Take it off your itinerary except as a place to change trains. I've never been to Interlaken, Lucern or Lake Geneva, but if I were you, I'd pick one. (Maybe post a question asking other RS travelers which they prefer and why?) I have spent lots of time in Lake Como, Venice, and Cinque Terra--and each is worth a week all by itself. But you're already staying on Lake Maggiore, so skip Como, and as another person said, CT is packed in July. Go to Venice! It will be full of tourists too, but it's bigger than CT or Como, and it's unique.

So, if it was me, I'd fly into Rome, spend 4 nights, then get to Switzerland the fastest way possible and stay in one of those locations for another 4 nights. Then the conference, then Venice, then back to Rome.

Instead of staying in Interlaken, go up into the mountains where the breathtaking beauty of the Berner Oberland is located Grindelwald, Murren, Wengen.

Thank you so much for all the input.

Hi we finally get a final plan
We will stay in Lucern for 3 nights and wengen for 4 night , then go to stresa
We plan to go to the mountains, boat trip and lots of hiking
We plan to get half fare pass but wonder should we get a tellpass Switzerland and or jungfrau pass as well?