San Mateo County Treasurer/Tax Collector, Sandie Arnott, an elected official, is charged with managing and protecting the County’s financial assets. She acts as the banker for the County and directs the investment of the County’s funds. The funds are invested in a portfolio of credit instruments called a pool. County Pool depositors include the County of San Mateo, elementary schools, high schools, community colleges and various other special districts and agencies within the County. It is the Treasurer’s mission to provide all pool participants with safety, liquidity and yield on their investments.


  • The Treasurer’s Office is open to the public from 9:00 AM - 5:00 PM, Monday through Friday
  • Beginning March 15, 2022: Masks are optional for visitors of County facilities, but are strongly encouraged

Recent Reports

Investment:        April 2023

Compliance:       May 2023

Absent Heirs:     May 2023

Closed RFP:       RFP for Operational Banking Services

Investment Reports Outgoing Wire Transfer Request Form for Pool Participants