The Contra Costa County Treasurer–Tax Collector’s Office has announced that December 10 is the final day to pay the first installment of property taxes without incurring a penalty. Payments made after this deadline will be subject to a 10% penalty.
To assist taxpayers, the office provides several payment options. Residents can pay online through the Tax Portal, by phone using an automated system at (925) 608-9500, or by mailing a check with the provided envelope. Mailed payments are considered on time if they bear a valid USPS postmark.
For those preferring in-person transactions, payments can be made at the Contra Costa County Finance Building located at 625 Court Street, Suite 100 in Martinez during business hours from Monday to Friday, 8 a.m. to 5 p.m.
A new drive-thru drop box has also been introduced for added convenience. It is available 24/7 on the Main Street side of 625 Court Street in Martinez and accepts check payments only.
Additionally, residents are encouraged to sign up for Paperless Billing to receive email reminders and secure access to billing information while reducing paper clutter.
Payments received after December 10 will be considered late and will incur a penalty as specified by county officials.
