When Are Property Taxes Due in San Diego County?

Annual secured property taxes in San Diego County are due in two installments: the first on November 1 and the second on February 1. The first installment becomes delinquent after 5 p.m. on December 10, and the second after 5 p.m. on April 10. Miss either delinquency date and the county adds an automatic 10% penalty with no grace period and no warning.¹

The Two Annual Installments

The San Diego County Treasurer-Tax Collector splits annual secured property taxes into two installments covering the fiscal year that runs July 1 through June 30.

The first installment covers July 1 through December 31. It is due November 1 and delinquent after 5 p.m. on December 10.
The second installment covers January 1 through June 30. It is due February 1 and delinquent after 5 p.m. on April 10.

You can pay both installments together when the first comes due in November if you prefer to be done with it. If either delinquency date falls on a weekend or legal holiday, the deadline shifts to 5 p.m. on the next business day.²

The gap between the “due” date and the “delinquent” date is not a grace period. Your payment is on time whether it arrives November 1 or December 9. On December 11, it is late by the full 10% penalty.

Supplemental Tax Bills Follow a Different Schedule

When you buy a property or finish new construction, the Assessor reappraises it at current market value. The difference between the old assessed value and the new one, prorated for the months remaining in the fiscal year, produces a supplemental tax bill that arrives separately from your annual bill.³

Supplemental delinquency dates depend on when the bill is mailed:⁴

Bills mailed July through October: first installment delinquent December 10 of the same year, second installment delinquent April 10 of the following year.
Bills mailed November through June: first installment delinquent the last day of the month after the mailing month, second installment delinquent the last day of the fourth month after that first delinquency date.

Watch for these bills in the first year or two after a purchase or major construction. They arrive at your door, not your lender’s.

Unsecured Property Tax Due Dates

Unsecured property taxes apply to property that isn’t tied to real estate: boats, aircraft, business equipment, and business fixtures. For property enrolled between January and July, which covers most bills, the tax is due by August 31 and delinquent on September 1. Property enrolled later in the year is due on the last day of the month after its enrollment month. Property enrolled in October, for instance, is due November 30 and delinquent December 1.⁵ The weekend-and-holiday rule applies here too.

If Your Mortgage Company Pays Your Taxes

Where a mortgage includes an escrow account for property taxes, the lender collects a share of the taxes each month and pays the county directly when installments come due. The annual secured bill is mailed to the lender rather than to you, and most homeowners with escrow accounts never cut a check to the county for annual taxes.

Verify the payment anyway. You can check status on the Treasurer-Tax Collector’s website using your parcel number. If your lender misses a deadline, the county holds you responsible for the penalty; any dispute with the lender over who should have paid is a private matter between the two of you.

Supplemental bills are the critical exception. Lenders do not receive them, even for borrowers whose annual taxes are handled through escrow. You pay those directly or arrange payment with your lender yourself. The Board of Equalization specifically warns that penalties caused by confusion between you and your lender over who should pay cannot be excused.³

What a Late Payment Costs

Penalties for late secured property taxes are automatic and steep.

First installment delinquent after December 10: a 10% penalty on the unpaid amount.⁶
Second installment delinquent after April 10: a 10% penalty plus a $10 cost.⁶

On a $4,000 installment, the 10% penalty alone is $400. There is no reduced penalty for being one day late. December 11 costs the same as February 1.

Unsecured taxes also carry a 10% penalty when late, and after two more months of nonpayment, an additional 1.5% per month begins accumulating on the delinquent balance.

If both annual installments remain unpaid at 12:01 a.m. on July 1, the property enters tax-defaulted status. The county then charges a redemption fee and starts adding 1.5% per month to the outstanding balance, which compounds to 18% per year.⁶ You can redeem the property at any time by paying all outstanding taxes, penalties, and fees. After five years in default, the tax collector gains legal authority to sell the property at public auction; for commercial properties also carrying a nuisance abatement lien, that window shortens to three years.⁷

When the County Will Cancel a Penalty

California law lets the tax collector cancel a penalty when the late payment resulted from circumstances genuinely beyond your control, such as a serious medical emergency, a postal service failure, or a natural disaster. The standard is that you exercised ordinary care and the failure was still unavoidable. Inconvenience and forgetfulness do not qualify.⁸

Penalties can also be canceled when you made a payment-amount error, as long as you pay the correct amount within 10 days of receiving the county’s shortage notice.⁸

To request cancellation, submit a completed Request for Cancellation of Penalties form from the Treasurer-Tax Collector’s website with documentation supporting your claim. A written response usually takes four to six weeks and longer around the December and April delinquency periods.⁹

One common scenario that does not qualify: a mortgage company’s failure to pay a supplemental bill on your behalf. The state treats that as a dispute between you and the lender, not a basis for relief.

How to Pay On Time

San Diego County accepts payment through several channels. The option you choose can affect whether the county treats your payment as timely.

E-check online through the Treasurer-Tax Collector’s website is free and gives immediate confirmation. You enter your bank routing and account numbers directly.¹⁰
Credit and debit card payments online carry a 2.19% convenience fee on the total transaction. On a $5,000 bill, that adds about $110.¹¹
By mail: San Diego County Treasurer-Tax Collector, P.O. Box 129009, San Diego, CA 92112. The USPS postmark date, not the date the county receives the envelope, determines whether the payment is on time.¹²
By phone at 1-855-829-3773.
In person at 1600 Pacific Highway, Room 162, San Diego, CA 92101.¹⁰

If you mail a payment, use the U.S. Postal Service rather than a private courier. The postmark rule applies to USPS postmarks specifically, and a metered stamp from your office or a private carrier receipt may not be treated the same way. The burden of proving a timely mailing falls on you.

If a bill never reaches you, you are still responsible for finding it and paying by the deadline. The Treasurer-Tax Collector’s website lets you look up current and prior-year tax bills by parcel number or property address.¹³ The county does not waive penalties because a bill went to the wrong address or got lost in the mail.

1
San Diego County Treasurer-Tax Collector. Last Day to Pay 1st Installment of Property Taxes Due December 10, 2025
2
California State Board of Equalization. Property Tax Annotations 325.0015 – Deadlines Falling on Saturdays, Sundays, and Holidays
3
California State Board of Equalization. Supplemental Assessment
4
California Legislative Information. California Revenue and Taxation Code – Chapter 3.5, Article 6
5
San Diego County Treasurer-Tax Collector. Unsecured Property Taxes
6
County of San Diego. Property Tax Frequently Asked Questions
7
State Controller’s Office. Public Auctions and Bidder Information
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California Legislative Information. California Revenue and Taxation Code 4985.2
9
San Diego County Treasurer-Tax Collector. Canceling Penalties
10
San Diego County Treasurer-Tax Collector. Why Pay Property Taxes Online
11
City of San Diego. San Diego Administrative Code SEC. 371 – Fee for Credit Card and Debit
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San Diego County Treasurer-Tax Collector. Contact Us
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San Diego County Treasurer-Tax Collector. Treasurer-Tax Collector Home