City of Phoenix
Mistabar is a merchant kingdom, and as such it has a highly evolved system of banking. There are several banks in Phoenix which deal with both businesses and individuals. Banks accept deposits, make loans, issue letters of credit against holdings, and appraise items. Opening an account with a bank usually involves paying a fee and making a deposit. Most banks have rules regarding the minimum amount you must have to maintain an account, how much they get to charge you for looking after your money and other things that regulate how the bank works.
In general it costs a small fee each month to have an account with the average bank. This is usually a fixed amount. Things get more complicated if you have large accounts or if you deal with a bank which offers special incentives like paying interest on your money!
For game purposes banks will do pretty much what modern banks do in their brick and mortar offices. Obviously things like credit and debit cards don’t exist and checks are only things that businesses usually use.