Day trip to Innsbruck from Bolzano — Regional trains?

Sounds lie a good plan. Not only are the regional connections more frequent than through trains, they are not all that much slower, only about 10 to 15 minutes for a 2 hour or so trip.

Thanks, Sam. I also noticed that there wasn’t a big difference in terms of travel time.

I will have to see if I can download an app to buy the S-Bahn tickets in advance instead of having to go to a ticket machine.

Everyone uses the mobile apps these days. It takes 40 minutes and trains run hourly in the middle of the day.

https://www.oebb.at/en/

NickB, thank you

A ticket for the S-Bahn will be a VVT ticket, also valid on local transport in Innsbruck. If there are two or more of you travelling the best option is probably to get the Day Ticket for 42,60, which is good for 2 adults and up to 3 children, and gives you unlimited use of all public transit in Tirol. See www.vvt.at

Note that there are a few through regional trains between Bolzano and Innsbruck. You can use the split ticket trick you have in mind on those as well. It is not necessary to get out and change trains in Brenner. As long as you are on a regional train you are fine.

Brenner-Innsbruck as a one way ticket is €11, so €22 for the round trip. The discount options only really add up if there are 2 of you, if you intend to just walk around Innsbruck the Einfach Raus ticket (€38 for 2 people) would be cheaper than 2 round trips or the VVT ticket (but not valid on RJ trains). The VVT day ticket becomes useful if you were also using the tram or buses to get around Innsbruck. You need to put your exact circumstances into the app to find the best offer.

And well done for understanding that your Guest Pass covers you to Brenner, I've had to explain this several times in the last month!

high-speed rail ticket

Unless things have changed, the only trains on these tracks are slow and slower.

toby is correct about these tracks, but some of the trains in both directions from Bozen are classed as high speed because eventually they find their way onto suitable track. The important thing is that the regional trains run under contract to the local authorities (in different ways, on both sides of the border) who set the fare system and usually pay subsidy to the operators. The high speed trains are outside of these contracts, they don't get the subsidy and don't accept the local tickets. Bizarely the high speed trains can be cheaper - if you book a few months in advance, on a specified train, at a quiet time of day and can stick to that plan. But as the original query says, flexibilty on the day was the key requirement here.