I'm having a "discussion" with my mortgage broker just now, as we swapped mortgage providers when we did our final purchase, and got a better rate. Did everyone sign a confirmed mortgage contract 2 years ago and then stuck with the same bank, or did you get a promissory note (I think a rahmenvertrag) which game the flexibility to chooses a different provider later?
Basically put, was your first mortgage framework agreement binding, or could you change it later if you had wanted to?