Many! Temples and guilds (for their members only, or those trying to pay their members) act as banks. So does the city (Piergeiron's Palace). And for those who want "off the books" transactions, there are many, many private moneylenders (such as the infamous Mirt).

— Ed Greenwood (@TheEdVerse) November 9, 2017

It's my pleasure to dish out Realmslore, to make everyone's games richer if possible, and less headachy for overworked DMs. Remember: it's canon until contradicted by newer official Realmslore (from Wizards), who always have new products up those stylish sleeves! :}#Realmslore

— Ed Greenwood (@TheEdVerse) January 13, 2021