Sonoma County Defaulted Property Taxes - Parcel, Balance Due

Sonoma County Defaulted Property Taxes

Defaulted secured property-tax bills in Sonoma County, California - the step before a tax sale. One row per defaulted tax year of a parcel, from the county's public open data, refreshed daily (newest county update 9 November 2026).

Low cost

From $0.00005 per record, down to $0.00003 at Gold.

What you get

Each record is one defaulted tax year of one parcel:

• assessmentNumber, feeparcel - the assessment (parcel) number and the fee parcel it sits on (2,746 rows differ after a parcel split)
• originatingAssessmentNumber - the original assessment number when the parcel was split
• taxYear, rollYear, taxRateArea - tax-rate year, roll year and rate area
• defaultNumber, defaultDate, billDate - the county's default reference, default date and bill print date
• totalDue - base tax + 10% penalty + cost charge for that tax year
• balanceDue - totalDue minus what has been paid (never negative)
• baseTaxAmount, penaltyAmount, costCharge, paidAmount
• defaultAmount - the county's first-year default amount (see below)
• amountBasis - components when totalDue comes from the three components, defaultAmount on the 72 rows where all three are 0 and the county's default amount is the only figure available
• redemptionFee, redemptionTotalFees, priorYearTaxesPaid, delinquencyInterestPaid
• redeemedDate, saleNoticeDate, status - outstanding or redeemed (our derivation from the redemption date and amount paid; mode="parcel" can also say mixed when a parcel's tax years disagree)
• redemptionPeriodEnd, yearsInDefault, powerToSellRecorded - the California five-year power-to-sell timeline
• netValue, agPreserve - net assessed value and the agricultural-preserve flag
• exemptionCode1 / exemptionLabel1 / exemptionAmount1 (and slot 2) - the county exemption, e.g. E01 Homeowner
• address, city - the property's own location

How the money reads

The county publishes one row per defaulted tax year, and the amount fields do not all mean the same thing:

• totalDue is the figure to use per tax year. It follows the county's own redemption formula (base tax + 10% penalty + cost charge); 1,913 of the 2,043 redeemed parcels (93.6%) have paidAmount equal to their summed totalDue as delivered (1,972 match if you sum only the three components - the difference is the fallback rows below).
• 95 rows have all three components at 0 while the county still records an amount (72 of them non-zero, $782,473 in total across 72 parcels - large assessments whose tax detail was never broken out). On those, totalDue falls back to defaultAmount and amountBasis says defaultAmount. Without that fallback those parcels - including 68 whose every row has zero components - would read as owing nothing. The fallback applies to the single row that carries defaultAmount; the parcel's other zero-component tax-year rows still show totalDue=0 in rows mode - use mode="parcel" for the parcel's combined amount.
• defaultAmount exists on one row per parcel only - the earliest tax year of the default. On the other tax-year rows of the same parcel it is 0, and a 0 there does not mean "nothing is owed"; use totalDue.
• A redeemed row can still carry a balance. 81 rows have a partial payment (0 < paidAmount < totalDue), and 142 redeemed rows in total show balanceDue > 0 (the remainder are fallback rows whose default amount exceeds what was paid, including rows with paidAmount=0). So status="redeemed" and balanceDue > 0 can both be true. Use minBalanceDue to find money still owed rather than relying on status alone.
• redemptionTotalFees, priorYearTaxesPaid, redeemedDate and saleNoticeDate are default-record values repeated on every tax-year row. Do not sum them across rows. defaultDate is normally the same on every row of a parcel too, but two parcels in the current file carry more than one default date.
• taxYear is the tax-rate year, not the default year. A default recorded on 30 June 2026 can carry tax years 2023-2025; taxYear="2026" returns nothing.
• These are the county's redemption figures. They do not add the interest that keeps accruing, so they are not a title company's payoff quote.

The five-year timeline

California lets the tax collector record a power to sell once a property is five years delinquent. The source's saleNoticeDate is exactly that event. We surface it three ways:

• redemptionPeriodEnd = defaultDate + 5 years (a statutory calculation, not a county promise)
• yearsInDefault = years since the default date
• powerToSellRecorded = true when a sale notice is on record, else false

332 rows carry a sale notice; 242 of them are still outstanding. Sale notices appear only on defaults from 2014-2021 - consistent with the five-year rule.

Examples

The 50 newest defaults:

{ "mode": "rows", "maxResults": 50 }

One parcel - 13 defaulted tax years, outstanding, power to sell recorded:

{ "mode": "parcel", "assessmentNumber": "095032008000" }

Still outstanding, at least $5,000 due in a single tax year:

{ "status": "outstanding", "minTotalDue": 5000, "maxResults": 200 }

Money still owed (a partial payment leaves a balance even on a redeemed row):

{ "minBalanceDue": 1000, "maxResults": 200 }

Defaulted tax-year rows where the county has recorded a power to sell (332 rows across 80 parcels):

{ "hasSaleNotice": true, "maxResults": 100 }

Homeowner-exemption rows:

{ "exemptionCode": "E01", "maxResults": 100 }

Defaults from the 2024 delinquency year onward (every default date in the file is 30 June):

{ "defaultYearFrom": "2024", "maxResults": 100 }

Defaults by tax year:

{ "mode": "aggregate", "groupBy": "taxYear" }

Defaults by city:

{ "mode": "aggregate", "groupBy": "city" }

Coverage and honest limits

• 9,789 tax-year rows across 6,776 parcels at build time. Rows are neither parcels nor bills: one parcel can carry up to 13 defaulted tax years.
• 7,321 rows outstanding (4,733 parcels) and 2,468 rows redeemed (2,043 parcels).
• 1,724 rows carry an exemption in slot 1 (1,619 of them E01 Homeowner). Unknown codes are returned with an empty label rather than a guess.
• The dataset is the county's defaulted list. It is not every delinquent bill in the county, and it does not include the full payoff quote a title company would compute.
• No owner name is published in this dataset. The owner's mailing address is deliberately excluded - only the property's own location is returned.
• bankruptcy and taxability are omitted: the source returns "No" / null on every row, and a column that never varies carries no information.
• The source's four "value split" columns (billedmarketlandvalue, billedfixedimprvalue, billedgrowingimprvalue, billedstructuralimprvalue) are identical to each other on every one of the 9,789 rows, so they are not a land/improvement breakdown and are not exposed; netValue is.
• 12 rows have no location address and 15 no city in the source; the city filter also cannot reach 20 rows whose combined field holds only CA. Address or city filters therefore skip 12 and 35 rows respectively.
• mode="parcel" returns the parcel's rollup: defaultNumbers, firstDefaultDate, latestDefaultDate, taxYears, recordCount, totalBaseTax, totalPenalty, totalCost, totalDue, totalPaid and balanceDue sum the parcel's tax years, while defaultAmount stays the first-year figure. The property fields (address, netValue, exemption*, agPreserve, taxRateArea) come from the parcel's most recent tax-year row - an exemption that existed only in an earlier year is not carried forward.
• A single run can deliver the whole file (9,789 rows; the cap is 10,000). Larger pulls are metered per record. When maxResults or the run-level charge cap stops a query, the dataset also carries one unbilled _meta row with truncated, delivered (a lower bound when stopReason="charge-limit"), totalMatched and stopReason.
• Assessment numbers are 12 digits in the source; a leading zero dropped by a spreadsheet is restored, so 95032008000 and 095032008000 are the same parcel.
• The county refreshes daily. New defaults appear in a batch each July; redemptions update through the year. sourceUpdatedAt is the county's last update date.

Related

Also available in this account: NYC Tax Lien Sale Lists (tax-lien sale notices with BBL, borough, block and lot) and CA county business licenses (Sonoma and Sacramento).