You can book these on the ÖBB site. Add the discount where it says 1 Adult, and then search for ‘one way tickets and day tickets’. Does that work?

You can also buy the supplement on board, I think, but it’s more expensive.

Also, most people advise that you don’t activate all the trips in advance, in case your plans change. Once it hits midnight, your travel day becomes used, and you can’t change your plans any more.

Yes, the on-board additional supplement is around €10 I believe.

Well, you can always change your trains but you can't deactivate the travel day anymore.

Thanks for the reply. I tried ‘one way tickets and day tickets’ and it still says ‘Tickets not available’, I’m aiming for the one departing at 07:44.

And noted on the trip activation, thanks for sharing that.

Hmm. There is availability on the 1244, so the method is correct.

It may be that the 0744 has sold out of passholder supplements, but I didn’t think they were quota-limited? Or it may be that it’s trying to make a seat reservation at the same time, and can’t do that.

It’s not a compulsory reservation train nEdit: yes it is, see below], so I think you can still just turn up and buy the supplement at the higher price onboard. In the mean time, check again later.

The 7:44 departure is fully booked according to Trenitalia.com.

The 8:44 departure is fully booked in 2nd class, still has a few seats available in 1st, but no pass holder reservations (there's a limited quota). If you have a pass for 1st class, you could book a reservation in 1st class from Domodossola, since it's only mandatory from that station and within Italy, there's no limited pass holder quota.

Other than that, you can change in Domodossola to a regional train:

Reservations in the EC are compulsory from Domodossola.

The 7:44 departure is fully booked according to Trenitalia.com.

The 8:44 departure is fully booked in 2nd class, still has a few seats available in 1st, but no pass holder reservations (there's a limited quota). If you have a pass for 1st class, you could book a reservation in 1st class from Domodossola, since it's only mandatory from that station and within Italy, there's no limited pass holder quota.

Other than that, you can change in Domodossola to a regional train:

 

Thanks for the reply, so I see that the train from Brig to Domodossola is also using the same EC35 train, how do I get on that then since it also require seat reservation? Btw I only have 2nd class pass .

Also I found this in thetrainline.com, wondering if this actually can be used and legit?

As @rvdborgt said, the reservations are only compulsory FROM Domodossola, to the rest of Italy on EC, IC, and Frecce trains.

In Switzerland this EC has no compulsory reservations, and has free seating with optional reservations. You can easily avoid it, by switching trains in Domodossola, and taking a regional train to Milan. It’s not even that slower than the EC.

If you don’t fancy a train that’s probably going to be quite full, there are also regional trains from Brig to Domodosola, if I’m not mistaken (IR/RE) not needing the supplement .

EDIT: Double checked, and I see less trains between Brig and Domodossola than usual. Maybe there are engineering works, limiting trains that day. Not uncommon in the easter period.

Best check timetables on the https://www.sbb.ch/en website. You can tweak the search by de-selecting EC/IC trains for that bit, under “advanced” search.

But still possible to do it entirely by reservation/surcharge free regional trains on that day (10/04):

Note you can also check the expected amount of travellers on that train via sbb:

@BrendanDB I can see the same trains as usual on the SBB app (I believe).

@Faiyah You could take the EC at 07:44 as it is indeed reservation-free until Domodossola. But it will be busy and you might have to stand.

I'd really take the RE train as advised by @BrendanDB

@rvdborgt @thibcabe @BrendanDB @ralderton I understand now, thank you very much for the explanation!