San Mateo County Property Tax Guide for Homeowners and Sellers

Last updated November 13, 2026. Reviewed by the Cash Home Buyers CA team. Figures come from the San Mateo County Tax Collector; sources are listed at the end.

San Mateo County property tax is paid in two installments: the first is due November 1 and delinquent at 5:00 p.m. on December 10, and the second is due February 1 and delinquent at 5:00 p.m. on April 10. A late installment carries a 10 percent penalty, and a late second installment also carries a $40 cost. If you sell, unpaid taxes are paid from your proceeds at closing.

San Mateo County property tax at a glance

First installment	Due November 1, delinquent at 5:00 p.m. December 10
Second installment	Due February 1, delinquent at 5:00 p.m. April 10
Late penalty	10% of the installment; the second installment also adds a $40 cost
After July 1	$35 redemption fee on delinquent parcels, plus a 1.5% monthly redemption penalty
Card payments	2.35% service fee, which the Tax Collector does not keep
Pay by phone	(866) 220-0308
Mail	San Mateo County Tax Collector, PO Box 45878, San Francisco, CA 94145-0878
In person	555 County Center, Floor 1, Redwood City, CA 94063
Transfer tax when you sell	$0.55 per $500 of the sale price at the county level; cities may add their own

When are San Mateo County property taxes due?

The first installment is due November 1 and becomes delinquent if it is not paid by 5:00 p.m. on December 10. The second is due February 1 and becomes delinquent after 5:00 p.m. on April 10. When a delinquent date lands on a weekend or holiday, the penalty is not imposed until 5:00 p.m. the next business day. The practical deadlines are therefore December 10 and April 10, not the first of the month.

• A U.S. Postal Service postmark, not a private postage meter date, decides whether a mailed payment is on time.
• Checks are payable to San Mateo County Tax Collector.
• If a lender pays through an impound account, confirm the payment posted before the delinquent date.

How do I pay my San Mateo County property tax bill?

You can pay by mail using the envelope and coupons supplied with the bill, by phone at (866) 220-0308 with Visa, MasterCard, Discover or American Express, on the Tax Collector’s website, or in person at 555 County Center in Redwood City.

Card payments carry a 2.35 percent service fee that the county does not retain. The county also notes that owners can pay the annual secured bill monthly through a program it links from the page; the page does not state the terms, so ask the office whether you qualify.

What happens if I don’t pay property taxes in San Mateo County?

A first installment paid after December 10 takes a 10 percent penalty. A second installment paid after April 10 takes 10 percent plus a $40 cost. Starting July 1, a $35 redemption fee is added to delinquent parcels along with a monthly redemption penalty of 1.5 percent.

The county’s page does not state a separate default interest rate or when a defaulted property can be sold, so ask the Tax Collector for the timeline on your parcel. Paying as early as you can stops the monthly penalty from growing.

San Mateo County property tax calculators

Use these to estimate your annual bill, what a late installment costs, and the transfer tax on a sale. Use the figures on your own tax bill for the closest result.

How to sell a house in San Mateo County when you owe property taxes

You can sell a house in San Mateo County with unpaid property taxes. Taxes are a lien on the home, so escrow pays what is owed from your proceeds at closing and the buyer receives the property with the taxes current.

1. Get your payoff figure. Contact the Tax Collector at (866) 220-0308 or taxmaster@smcgov.org. Ask for the amount due in the month you expect to close, since redemption penalties grow monthly.
2. Expect proration. Escrow splits the current year’s tax between you and the buyer by the closing date.
3. Budget for transfer tax. The county-level rate is $0.55 per $500 of the sale price, so a $1,200,000 sale is $1,320 before any city tax. Ask escrow what applies to your address.
4. Watch the calendar. Closing before December 10 or April 10 avoids the 10 percent penalty on that installment, and closing before July 1 avoids redemption charges.

A cash sale helps when time is the problem. There is no loan approval to wait for, so closing can be scheduled ahead of a tax deadline. See how we buy houses in San Mateo County, our local pages for San Mateo, Redwood City and Daly City, and the California real estate transfer tax report.

Behind on San Mateo County property taxes and thinking about selling? Call (424) 435-2326 or request a cash offer. There is no cost and no obligation.

San Mateo County property tax FAQ

What is the penalty for paying San Mateo County property tax late?

A late installment gets a 10 percent penalty, and a late second installment also gets a $40 cost. After July 1 a $35 redemption fee and a 1.5 percent monthly redemption penalty apply.

Can I pay San Mateo County property taxes monthly?

The Tax Collector says owners can pay the annual secured bill monthly through a program it links on its page. It does not state the terms, so ask the office about eligibility.

Where do I mail my San Mateo County property tax payment?

San Mateo County Tax Collector, PO Box 45878, San Francisco, CA 94145-0878. A U.S. Postal Service postmark by the delinquent date decides whether it is on time.

Who pays property tax in the year a San Mateo County house is sold?

Both sides, each for their share of the year. Escrow splits the bill by the closing date and pays any unpaid balance from the seller’s proceeds.

How do I sell a house in San Mateo County with delinquent property taxes?

Get the payoff amount from the Tax Collector, give it to escrow, and the delinquent taxes are paid from your proceeds at closing.

Sources

• San Mateo County Tax Collector: Secured Property Taxes

This guide is general information, not tax or legal advice. Rates, fees and dates can change; confirm the amount on your own bill with the San Mateo County Tax Collector.