Nassau County Tax Collector. If you have not been able to book an appointment for your service type, please try again at 8:30 a.m. tomorrow. The Property Appraiser determines the value of all property in the county, approves and calculates various tax exemptions, and develops a Tax Roll that includes the legal description of the property and the mailing address of the owner. Phone (904) 255-1916 Duval County Tax Collector's Office 231 E Forsyth S Jacksonville, FL 32202-3361. Duval County Tax Office does not warrant the accuracy, authority, completeness, Duval County was named for William Pope Duval, the first territorial governor of Florida. Many answers regarding property taxes can be found in the FAQ section of this website. //-->. If you own property and do not receive a bill you are still obligated to pay the tax. DUVAL COUNTY TAX OFFICE PO BOX 337 SAN DIEGO, TX 78384-0337 (361) 279-6338 You may also e-mail the office.