You may receive more than one supplemental tax bill, depending on when you purchased your property or completed new construction. Since the secured property taxes are based on the January 1 value and cover a fiscal year, your purchase/construction date may affect the calculation of the taxes for two fiscal years. For example, if you purchased property in February 2019, your purchase would affect the 2018/2019 fiscal year taxes (July 2018 through June 2019). The latter fiscal year is affected because the Assessor would have already established the value on January 1, 2018, prior to the purchase/construction. Therefore, the taxes calculated for 2019/2020 would also have to be adjusted by a supplemental bill for the increased value.