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Due Dates and Penalties

Ownership Changes Backlog

Due to an extraordinary number of ownership changes, the Sonoma County Assessor’s Office is experiencing a significant backlog processing these changes. If you received a tax bill for a property you no longer own, please write “sold” on the bill and return it to our office. Should you need additional assistance please reach out to our office at (707) 565-2281 or taxcollector@sonoma-county.org.

Payment Deadlines

Secured Tax Bills

You may pay your annual tax bill in two installments. The first installment is due November 1st and becomes delinquent at 5:00 p.m. on December 10th. The second installment is due February 1st and becomes delinquent at 5:00 p.m. on April 10th. If the delinquency date falls on a weekend, taxes are not delinquent until 5:00 p.m. the next business day.

You may, however, elect to pay the entire bill when you pay the first installment. If you itemize your income taxes, this may be an advantage to you when calculating the deduction on your Federal and State income taxes. All tax bills become delinquent after 5:00 p.m. on the due date. Payments left in our drop box after 5:00 p.m. on the date due will be considered delinquent. Read our section on Secured Property Taxes for more information.

Supplemental Tax Bills

Supplemental tax bills are mailed throughout the year and, therefore, may not be due or delinquent at the same time as your annual tax bill. Read our section on Supplemental Property Taxes for information on delinquency dates of supplemental tax bills. 

Unsecured Tax Bills

Unsecured taxes are mailed in July of each year and are due by August 31st at 5:00p.m. If the delinquency date falls on a weekend, taxes are not delinquent until 5:00 p.m. the next business day. The unsecured bills are due in full and do not have installments. Read our section on Unsecured Property Taxes for more information.

Penalties

If you do not pay the first installment of your annual secured tax bill at the Tax Collector's Office by 5:00 p.m. on December 10th (if December 10th falls on a weekend, taxes are not delinquent until 5:00 p.m. the next business day), or payment is not postmarked by that time and date, then the taxes become delinquent and a 10% delinquent penalty is added.

 If you fail to pay the second installment of your annual secured tax bill at the Tax Collector's Office by 5:00 p.m. on April 10th (if April 10th falls on a weekend, taxes are not delinquent until 5:00 p.m. the next business day), or payment is not postmarked by that time and date, it becomes delinquent and a 10% penalty plus an administrative charge of $20.00 is added. Per Revenue and Taxation Code, State of California (Section 2703) the second installment of taxes may be paid separately only if the first installment of taxes has been paid. 

If you fail to pay either or both installments of your annual secured tax bill at the Tax Collector's Office by 5:00 p.m. on June 30th (if June 30th falls on a weekend, taxes must be paid by 5:00 p.m. on the preceding business day), or payment is not postmarked by that time and date, then the property becomes tax defaulted and additional penalties and costs accrue. See our FAQ section on Delinquent Taxes for full information.

If you fail to pay the installments of your supplemental tax bill by the applicable delinquency dates, the same penalties accrue as for delinquent annual taxes. Read our section on Supplemental Property Taxes for more information.

If you fail to pay your Unsecured Property Taxes by the delinquency date, a 10% penalty will be added. If the unsecured bill remains unpaid on the last day of the second month after the 10% penalty was added, an additional penalty of 1.5% will accrue on the first day of each month until paid. The unsecured bills are subject to lien and an additional fee of $120.00 if they remain unpaid and are referred to our Central Collections department.

Returned Payment Fees

When paying online or with a check, a $30 processing or Non-sufficient funds fee will be added to any returned payments. This includes, but is not limited to, incorrect account information submitted during online payment, non-sufficient funds for either electronic payment or check and submitting account information for closed accounts.

Please Note: If a payment is returned after the due date, additional tax penalties (listed above) may apply.

Due Dates

January 1:

  • Lien Date - date for valuation, date taxes attach to property as a lien

January 2:

  • Exempt entities; first day to file affidavit and claim for exemption (delinquent 5:00 p.m. on February 15)
  • Churches and Churches with schools; first day to file affidavit and claim for Church or Religious exemption (delinquent 5:00 p.m. on February 15)
  • Homeowners Veterans, Disabled veterans; first day to file affidavit and claim for exemption (delinquent 5:00 p.m. on February 15)

February 1:

  • Second installment secured property taxes due (delinquent April 10)

February 15:

  • Commercial fishing vessel and historical aircraft exemption claim forms due.
  • Exempt entities; affidavits and claim forms dues
  • Churches and churches with schools; affidavits and claim forms due

April 1:

  • Property statements due (delinquent after May 7 or Assessor's date)

April 10:

  • Property owners; second installment of current year tax due

May 7:

  • Final filing date for property statements

July 1: (First day of Fiscal Year)

  • Assessors complete local roll and deliver to auditor

July 2 - November 30:

  • Assessment Appeals filing period for regular-period assessments. Most other assessments must be appealed 60 days after notice.

July 31:

  • Last day for tax collectors to issue unsecured tax bills

August 1:

  • Commercial fishing vessel and historical aircraft exemption claim forms due for partial exemption.

August 31:

  • Unsecured taxes due; delinquent after 5:00 p.m.

November 1:

  • First installment of secured taxes due (delinquent Dec. 10)

November 30:

  • Last day to file assessment appeals

December 10:

  • Property owners; first installment of current year tax due