The City Treasurer is a position of responsibility for a city according to the prevailing laws in that city. The treasurer of a public agency is elected  by the voting public or is appointed by the city council or city manager. City treasurers are primarily responsible for managing the revenue and cash flow of the agency, banking, collection, receipt, reporting, custody, investment or disbursement of municipal funds.
They also typically advise the city council and city manager, or their equivalents, on matters relating to municipal finance.
They could also have oversight of other areas, such as the purchase of insurance, and collections of user fees such as utility usage and business licenses. Municipal funding sources are commonly property tax, sales tax, income tax, utility users tax (UUT), transient occupancy tax (hotel occupancy), and user fees such as licensing and permit fees.
Elected city treasurers may only be required to be of legal age, over 18, for example, meet minimum residency requirements, perhaps six months or one year, and be a registered voter. With no training requirement, citizens may have a legitimate concern and may impose post-election training requirements once in office. Some US states offer but may not require, extensive training and certification programs, such as the Certified California Municipal Treasurer.
Appointed city treasurers, not subject to residency requirements, are likely to be subject to competition and likely must have finance-related college degrees, prior investment experience, municipal department head experience and appropriate training and certifications.