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Tax-Defaulted Property Auctions in Sonoma, Napa and Marin Counties

By Matthew Martinez, Founder, CEO & Managing Broker, Diamond Real Estate Group. California DRE #01869679.

A California tax-defaulted property auction is a public sale, run by the county tax collector, of property whose secured property taxes have gone unpaid for at least five years, or three years for nonresidential commercial property, under Revenue and Taxation Code section 3691. Sonoma County runs its sales online through Bid4Assets, most recently in November 2025; Napa County’s last listed sale was on GovEase in September 2023, and Marin County’s was on Public Surplus in March 2024, with none scheduled when its page was last updated. Every parcel is sold as is, the county does not guarantee title, and most title companies will not insure for a year after the tax deed is recorded.

This guide explains how these sales work from the bidder’s side: the legal timeline, what the tax deed conveys and what survives it, how each of the three North Bay counties has run its recent sales, and the research to finish before you register. It sits alongside our other guides to buying REOs and short sales. Facts are as of October 2026.

How a property ends up at a tax sale

Unpaid secured property taxes eventually put a parcel into tax-defaulted status, and penalties and redemption charges build from there. The owner can redeem by paying everything owed. Section 3691 gives the tax collector the power to sell once the property has been in default for five years or more, or three years or more for nonresidential commercial property, which the statute defines as everything except permanent residential property and land used and zoned for commercial agriculture.

Who may bid: section 3691 says any person may purchase, regardless of any prior or existing lien.
Disaster damage: for property damaged in a declared disaster and not substantially repaired, the five-year clock is tolled until five years after the damage.
Nuisance abatement liens: a separate three-year track applies to property with a recorded nuisance abatement lien, but only when a public agency, nonprofit or lienholder requests the sale.
Postponement claims: a county may vote to delay sales of property whose owner may have been eligible to file a state property tax postponement claim before January 1, 2017.

Many parcels on a sale list never sell, because an owner or someone else with an interest redeems them first, as Sonoma County’s 2025 results below show.

The redemption deadline and the minimum bid

The owner’s right to redeem ends at the close of business on the last business day before the sale begins, under section 3707. For an online sale that runs over several days, the start date is what counts. If the parcel does not sell, the right of redemption revives.

That rule explains the attrition. Of the 57 parcels on Sonoma County’s November 2025 list, the results posted on the county’s auction page (as viewed in October 2026) show 18 sold, 34 redeemed, 3 withdrawn and 2 with no bid. A bidder can research a parcel for weeks and see it disappear the day before the auction opens.

For a parcel offered for the first time, Sonoma County’s FAQ says the minimum bid is no less than the total needed to redeem plus costs, and the tax collector may set it higher. Bidding then runs up from there; on the November 2025 list, one parcel sold at its $140,700 minimum and another sold for $666,100.

What the tax deed conveys, and what survives

Section 3712 says the tax deed conveys title free of all encumbrances existing before the sale, with listed exceptions. A deed of trust recorded against the parcel is generally wiped out; these are not:

Survives the tax sale	What it means for a buyer
Tax and special assessment installments that come due on the secured roll after the sale	Budget the next bills from day one
Taxes and rights of a taxing agency that did not consent to the sale	Ask the tax collector which agencies consented
Special assessment liens not included in the redemption amount	Check for assessment districts on the parcel
Easements of any kind, including prescriptive ones, separately held water rights, and recorded restrictions	A neighbor’s road, a utility line or a CC&R can stay with the land
Recorded, unaccepted irrevocable offers of dedication and recorded public-purpose purchase options	Part of the parcel may be committed to a public use
Unpaid 1915 Improvement Bond Act assessments and Mello-Roos special taxes not satisfied by the sale	These can carry over at a significant cost
Federal IRS liens that federal law does not discharge	Have a title professional check for federal tax liens

The deed is also only as good as the sale. Sonoma County’s FAQ notes that a legal action to challenge a tax sale must be brought within one year of the tax deed’s recording, which is why title insurers usually wait out that year.

Title insurance, quiet title and occupants

Sonoma County’s FAQ says most title companies will not insure title for one year after the tax deed is recorded, and that a quiet title action may be needed. Plan on holding the parcel uninsured for at least that year, or on paying a real estate attorney to bring a quiet title action, before you can sell or finance it normally.

Two other practical points follow from the counties’ terms:

Possession: the county does not handle evictions. If someone is living on the property, removing them is the buyer’s job, through the courts.
Financing: payment is due within days, by wire, electronic transfer or cashier’s check, so tax sale purchases are effectively cash purchases. A conventional lender will generally want insurable title before it lends.

Sonoma, Napa and Marin: how each county has run its sales

County	Most recent sale listed	Platform	Terms worth knowing
Sonoma	November 7 to 10, 2025 (earlier sales in November 2023, September 2022, May 2022, October 2018 and October 2016)	Bid4Assets	$5,000 bid deposit plus a $35 processing fee, due before bidding; balance due by 1:00 p.m. PDT on November 13, 2025; county transfer tax of $0.55 per $500 plus city tax in Santa Rosa and Petaluma
Napa	Online sale starting September 6, 2023	GovEase	Sold “as is,” “Buyer Beware,” all sales final; no county guarantee of title
Marin	March 2024	Public Surplus (online only, no live auction)	No public auction scheduled as of the page’s February 10, 2025 update; anyone except Marin County Department of Finance employees can bid

Platforms change between sales, so treat this table as history and check each county’s page for the next one. Sonoma County publishes the parcel list in the Press Democrat three times in the month before a sale, and the tax collector’s office does not register bidders or take bids itself; Bid4Assets does. Sonoma also warns that a winning bidder who fails to pay cannot be replaced by the second-highest bidder, and may be barred from future county tax sales.

A sale list can mix improved property with rural lots, remnant strips and parcels with no clear access, so confirm what each one actually is. Our guides to land for sale in Napa County and Marin County land cover the access, septic and permit questions those parcels raise.

Due diligence before you register

The counties put the burden of research on the buyer. Sonoma’s terms say so in nearly those words. A workable order:

Pull the parcel map and assessor data. Confirm the parcel’s size, shape, access and whether it is a buildable lot or a strip.
Order a title search, at your own expense, for easements, recorded restrictions, assessment liens, Mello-Roos taxes and federal tax liens.
Check zoning, hazards and utilities with the city or county: flood and fire zones, sewer or septic feasibility, water source.
Look at the property from the road. You will not get an interior inspection, and you may find occupants or structures the listing does not show.
Budget the full cost, including the deposit, buyer’s fees, transfer tax, a possible quiet title action, a year of uninsured holding and the next tax installments, plus any supplemental tax bill after the new assessment.
Set a maximum bid from what the parcel is worth with clean title, less those costs and your margin, and do not chase it past that number.

The same discipline applies to bank-owned property; our REO due diligence checklist covers the inspection side, and our property tax guide for investors explains how the new assessment will be set.

Tax sale, trustee’s sale or REO?

A tax sale is one of several distressed-property channels, and it carries the most title risk. A trustee’s sale under a deed of trust also requires cash and offers no interior inspection, but the title questions are different, and the California foreclosure process that leads to it has its own notices; our comparison of foreclosure auctions and REOs explains that route. An REO, sold by a lender after foreclosure, usually comes with insurable title and a normal escrow; see investing in REO properties. For how these channels fit together, see our guide to distressed property investing.

Diamond may refer you to partners we work with, such as title officers or real estate attorneys; you’re free to choose any provider.

Questions people ask

When is the next Sonoma County tax sale?

The county’s auction page lists November 2025 as its most recent sale and, when we checked in October 2026, did not list an upcoming one. Check the tax collector’s page and Bid4Assets’ Sonoma page for the next date.

How long must taxes be unpaid before a California county can sell a property?

Five years or more after the property becomes tax defaulted, or three years or more for nonresidential commercial property, under Revenue and Taxation Code section 3691.

Can the owner pay the taxes and stop the sale?

Yes, until the close of business on the last business day before the sale begins. If the parcel does not sell, the right to redeem revives.

Do mortgages survive a tax sale in California?

Generally no; section 3712 conveys title free of prior encumbrances. Easements, recorded restrictions, some assessment liens, Mello-Roos taxes and federal tax liens not discharged by the sale are among the exceptions.

Can I get title insurance on a tax deed?

Usually not right away. Sonoma County’s FAQ says most title companies will not insure for one year after the tax deed is recorded, and a quiet title action may be needed.

Can I inspect a property before a tax sale?

Not inside, as a rule. Counties sell as is with no warranty, and the property may be occupied, so research from public records and the street.

Bids at a county tax sale are placed by the bidder directly on the county’s auction platform. If you are weighing a parcel at an upcoming sale, or would rather buy distressed property with insurable title, we can help you compare it with listed and bank-owned options and run the numbers. Contact us with the parcel number or your criteria.

This page describes California tax sale law and county practices in general terms and is not legal advice; a California real estate attorney or title professional should review a parcel’s title and any quiet title plan before you bid.

Sources & notes

Last reviewed October 2026 by Matthew Martinez.