Originally Posted by alex0683de

While you're correct that the BahnCard cannot be used for intra-Austria travel, since Salzburg also counts as a German station, the BahnCard rebate is applied to tickets originating in Salzburg as long as you purchase your ticket from Deutsche Bahn. You can also trigger the rebate when you buy tickets from ÖBB (the Austrian railway) by asking for a ticket from Freilassing (just across the border in Germany) to whatever your destination in Austria is. Because Freilassing is so close to Salzburg, the additional fare is minimal, but because it is in Germany, the cross-border rebate applies to the whole itinerary. This will also work when purchasing a ticket at other stations in Austria, but you will probably have to visit a ticket office to buy it.