The following are questions we often receive from San Mateo County unsecured property owners. For specific information, please call us at (866) 220-0308 or visit our office.

What are "unsecured" property taxes?

The term "Unsecured" simply refers to property that can be relocated and is not real estate. The tax is assessed against such things as business equipment, fixtures, boats and airplanes. If the unsecured tax is not paid, a personal lien is filed against the owner, not the property.

When is the unsecured tax assessed?

The Assessor establishes the value of the unsecured property on January 1. This date is often referred to as the Tax Lien date.

How are the unsecured tax amounts determined?

The January 1 value is multiplied by the tax rate (usually 1% plus voter approved indebtedness). The unsecured tax rate is the prior year secured rate.

What period of time does an unsecured tax bill cover?

An unsecured tax bill covers a fiscal year. The fiscal year begins July 1 and ends on June 30 of the following calendar year.

If I sell my unsecured property before the fiscal year, am I still responsible for the unsecured tax?

Yes. Disposal of the property after the January 1 lien date does not eliminate your tax liability. If you sell the property before the unsecured tax bill is issued, make sure you collect an estimated amount for the unsecured tax from the buyer.

When should I expect my unsecured tax bill?

Most unsecured bills are mailed before July 31. These bills must be paid on or before 5:00 p.m., on August 31. If the bill is mailed after July 31, the delinquent date is extended to the end of the month following the bill's issuance. In other words, if your bill is mailed in September, the delinquent date would be October 31.

If I don't pay on time, will I be charged a penalty?

Yes. If your payment is not received or postmarked by the delinquent date, a 10% penalty and a $35.00 collection fee are added to your bill. If your bill remains unpaid for two additional months, a monthly penalty of 1 and 1/2% begins to accrue. In addition, if a Certificate of Tax Lien is recorded, an additional fee of $25.00 will be required to release the lien.

When should I mail my payment to avoid penalties?

You can mail your payment, but in order to avoid the delinquent penalties, your payment envelope must possess an United States Postal Service postmark on or before the tax delinquent date.

Is a private postage meter date the same as the United States Postal Service postmark?

No. California law requires the Tax Collector to accept the US postmark, not a private meter date, as the date of payment.

If I don't pay my unsecured tax bill, can the Tax Collector take my property?

Yes. California law allows the Tax Collector to seize and sell the unsecured property or any other personal property owned by the assessee including bank accounts.

Who should I call if I have questions?

To speak to a live agent, call 866-220-0308 and follow the prompt.

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Hours of Operation 

Monday - Friday: 9 AM - 5 PM
Phone Hours are 9 AM - 5 PM (Monday - Friday)
Excluding all Holidays.

Make Tax Checks Payable to:
Sandie Arnott, San Mateo County Tax Collector

Mail Tax Payments to:
San Mateo County Tax Collector
PO Box 45878
San Francisco, CA 94145-0878