How does the bank in Game of Thrones / ASOIF work? Withdrawing, depositing, etc.
As people can't always carry around their winnings, how do they withdraw and deposit money?
The only bank we read about in the books is the Iron Bank of Braavos, which doesn't actually serve the common Westerosi. This doesn't however mean that there are no similar (though smaller) institutions elsewhere. However, since we have yet to come across any of them, then we can safely assume that once again they are not something the average Westerosi has access to.
Westeros is still a cash only society. Yes, you are expected to lug around all those gold dragons you won in the tourney with you. That's why we see wealthy merchants hire mercenaries and hedge knights to protect them (and by extension their money). Characters are often seen hiding their coins in inventive way to avoid losing it to a bandit.