Getting from Munich airport to Salzburg Hauptbahnhof?

Take the S8 Sbahn to the Munich Hbh, then book the next train to Salzburg. No need to book in advance for any regional train. See the DB website for details:

https://int.bahn.de/en

Thanks. I was looking at the DB website. Some routes take me through München Ost rather than München Hbf. Is it better to go through one or other?

after the early morning restrictions (not before 9am M-F) the whole family goes on one Bayern Ticket. 2nd class, regional trains only throughout Bavaria and to and from Salzburg. All the trains you can eat in one day.

5's and under are free, up to three 6-14's are included for free with the adult. 14 + are full adults on the ticket.

The Bayern Ticket = Bavaria Ticket in English.

https://int.bahn.de/en/offers/regional/regional-day-ticket-bavaria

be sure on that ticket not to get the IC services. Regional only.

Ost is a perfectly good change point. Just know that folks who boarded at the Hbf will already be on board. Ost means east.

There are 2 s-bahns from the airport, one clockwise in the middle of town, one counter clockwise. If you are on the one which gets to Ost first, perfectly fine to change there.

for a start we need the ages of the kids, but the answer is probably a Guten Tag Ticket . This is a group ticket which can be bought on demand and is valid on many trains in Bavaria including the S8 local train out of the airport and the RE5 regional express to Salzburg - which I'm guessing will be your only travel in Germany that day so you don't need all the extra stuff from the more expensive Bayern Ticket. The ticket cannot begin before 09:00 except at weekends and holidays but I doubt you will be ready to go that early.

The price depends on the group, it starts at €31 for the first person, you then add €10 for each additional passenger in the group (up to 5 in total). BUT up to three children up to the age of 14 can go FREE. So two adults and three under 15s will cost €41. You buy ONE ticket from the DB or MVV machines near the entrances to the platforms, the process will ask you to confirm the date and how many paying passngers there are, so if one child is 15 or older you set this to 3 people.

Between to airport and city you use the frequent S-Bahn trains, S8 is the best you take it to Ostbahnhof. (S1 actually has destination of Ostbahnhof but goes all the way around the city to get there so takes longer). At Ostbahnhof you take the RE5 regional express to Salzburg Hauptbahnof - yes, it is in Austria but is the fare boundary with Germany so this ticket is valid. They leave Ostbhahof at 4 minutes after eachhour and take 1 hour 42 minutes. You cannot use the slightly faster long distance trains.