San Bernardino County Auditor- Controller/Treasurer/Tax Collector (ATC) Ensen Mason encourages property owners to pay the second installment of their property taxes which were due by Thursday, February 1. The last day to pay without incurring a 10% penalty is Wednesday, April 10, 2024. The Tax Collector’s Office offers many convenient ways to pay, including online, by phone, by mail, and in person.