March 15th - Business return (S corporation, partnership and LLC) initial filing date and extension due date
April 15th - Individual, Trust and C corporation initial filing date and extension due date
April 15th - Q1 Estimated Taxes due (covering income and deductions through 3/31) and business CA minimum tax
June 15th - Q2 Estimated Taxes due (covering income and deductions through 5/31) and CA annual LLC fee, if applicable
September 15th - FINAL due date for business returns (S corporation, partnership and LLC); extended returns not filed by this date are subject to delinquency penalties
September 15th - Q3 Estimated Taxes due (covering income and deductions through 8/31)
September 30th - FINAL due date for trust returns; extended returns not filed by this date are subject to delinquency penalties
October 15th - FINAL due date for individual and C corporation returns; extended returns not filed by this date are subject to delinquency penalties
December 15th - Q4 Estimated Taxes due for business entities (S and C corporations)
January 15th - Q4 Estimated Taxes due for individuals & trusts (covering income and deductions through 12/31)