Important Tax Dates

The following schedule is intended to serve as a general guide to property owners in Contra Costa County, California. Please note that the list below includes only the more significant dates and does not include all items or activities in the regular, property tax-fiscal year cycle from July 1 to June 30.

JULY 1 - Beginning of a new fiscal year.  Close of assessment roll and the start of the new assessment roll year. The assessment roll is the official list of all taxable property within the County.  Unsecured Property Tax Bills are mailed out and can be found online.

JULY 2 - First day to file assessment appeal applications with the Clerk of the Board of Supervisors.

AUGUST – Redemption notices for delinquent/defaulted Secured Property Taxes from the prior fiscal year are mailed out.

AUGUST 31 - Unsecured Property Tax payment deadline. A 10% penalty plus $30 collection fee are added if not postmarked by August 31, received in our office as of 5:00 p.m., or before midnight online (*).

SEPTEMBER 1 - Unpaid Unsecured Property Taxes are transferred to the Collections Division.  Other fees are added by the Collections Division with continued delinquency.  Also, last day to request mailing address changes for annual secured tax bill.

SEPTEMBER - OCTOBER - Secured Property Tax bills are mailed out and can be found online.

NOVEMBER 1 - First installment of Secured Property Taxes due; liens are filed for all delinquent Unsecured Property Taxes and a 1.5% per month penalty is added to the outstanding amount due.

NOVEMBER 30 - Last day to file an assessment appeal application for reduced assessment with the Clerk of the Board of Supervisors for annual tax bills (*).

DECEMBER 10 - Last day to pay First Installment of Secured Property Taxes (late payments incur a 10% penalty if not postmarked by December 10, received in our office as of 5:00 p.m., or by midnight online (*).

JANUARY 1 - This is the date when taxes for the next fiscal year become a lien on the property.

FEBRUARY 1 - Second installment due on Secured Tax Bills.

FEBRUARY 15 - Deadline to file exemption claims timely and receive full exemption on Secured Property Tax bills collected in upcoming fiscal year.

APRIL 1 - Due date of filing annual business property statement.  A 10% late filing penalty will be applied if a statement is not received by May 7.

APRIL 10 - Last day to pay Second Installment of Secured Property Taxes (late payments incur a 10% penalty plus a $20.00 collection fee if not postmarked by April 10, received in our office as of 5:00 p.m., or by midnight online (*).

MAY - Delinquent notices for any unpaid First and Second Installment Secured Property Taxes are mailed out

JUNE 30 - End of fiscal year.  Last day to start a five-year payment plan for delinquent/defaulted Secured Property Taxes that have at least one installment delinquent for over five years and are eligible to start a payment plan.

JULY 1 Beginning of another fiscal year; and delinquent secured accounts are transferred to the defaulted tax roll and additional penalties added at 1.5% per month on any unpaid tax amounts, plus a $15 redemption fee—these bills are also referred to as prior year Secured Taxes or Defaulted taxes.

(*) If a delinquent date falls on a weekend or holiday, the delinquent date is the next business day.

NOTE: All Secured Property Taxes are pro-rated based on time of ownership.  All Unsecured Property Taxes and possessory interest assessments are not pro-rated and the owner on the January 1 lien date is responsible to pay 100% of the Unsecured Property Tax bill.  New Owner Secured Property Tax bills (after ownership of parcel changes) are mailed as updates are received from the Office of the Assessor.  Supplemental Property Tax bills are mailed monthly and are also prorated.