To claim the exemption, the homeowner must make a one-time filing with the county assessor where the property is located. Download PDF BOE-266 REV.For a complete list contact the Assessor, at (909) 387-8307. Q. When are tax bills due? Complete a homestead declaration form. Sign your declaration in front of a notary. Complete form BOE-266, Claim for Homeowners'. Property Tax Exemption. Buy a declared homestead form from an office-supply store, or download a form from the Registrar-Recorder's website. The Assessor will send you a Homeowner Exemption form in 2 to 3 months from your purchase date.