Tax Deadline 2024 San Diego State. Quarterly payroll and excise tax returns normally due on jan.  — residents and businesses in san diego county now have until june 17, 2024, to file certain california state individual and business tax returns and make tax payments originally due between.

31 and april 30, 2024.  — affected individuals and businesses in san diego county now have until june 17 to file their tax returns and pay federal and state taxes due between january 21.