Yes, you can do that (your "local lord" is sometimes that figure). However, temples all across the Realms act as banks (and a sort of "Pony Express" post office, too).
#realmslore
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Pratz Strike
@PratzStrike
Replying to @TheEdVerse
Yeah. I thought it was like old school banking - you took the money to an independent bank or failing that, an authority figure you trusted to keep an eye on it, and traded scrip. Plus a bag of holding can hold a lot of cash. Failing all that, build a fort and vault with troops.