Ever since LY 117 (ten years after the introduction of money), the villages of The Land had built up public funds to use for various services of importance to the village as a whole. These funds were stored in a centralized location, and the distribution of funds for goods and services was decided by popular vote. The places where the funds were stored were not locked, early on, but eventually it was discovered to be necessary that they should be. Nevertheless, the buildings where public funds were stored were, of course, public. Meanwhile, individuals had nowhere but their own homes to store their own money (though it was not uncommon, especially among adventurers, to find various hiding places for money in other random spots).
It was not until 902 that The Order suggested establishing a system of banks (as part of The Plan), institutions created especially for the safekeeping of money. Banks would also provide services such as loans, interest-bearing savings accounts, and managing investments (such as stocks). Also introduced upon banks' founding was the use of paper checks, which could be used to pay for goods and services without carrying around bulky and heavy coinage. Banks could also stay in contact with each other, even between villages, using t-mail, thus allowing them to confirm that customers had specific amounts of money in their accounts. This was particularly convenient for people who traveled between villages.
Later that year, the tax law was passed. Each year thereafter, on 15 Aut'gin, people would be required to pay taxes to contribute to their village's public fund (and later also to the Second Order's public fund). On or around that day, people would deposit their taxes in special accounts which were held by village (or federal) trustees. In 905, the Treasury Department was established, which took over responsibility for overseeing the running of banks as well as the collecting of taxes. (Beginning in late 905, taxes would be paid by employers each pay period, deducted from the pay of their employees, rather than having employees keep track of how much they owed, and paying it once per year.)