The Lien Date Explained: Revenue and Taxation Code Section 2192 in Plain Words

California Revenue and Taxation Code section 2192 is one sentence: "Except as otherwise specifically provided, all tax liens attach annually as of 12:01 a.m. on the first day of January preceding the fiscal year for which the taxes are levied." In plain words, once a year, one minute after midnight on January 1, the property tax for the coming tax year becomes a legal claim against the property, and that January 1 becomes the date the property's value for that year is measured. The lien date is not a filing deadline, and it is not the day the bill arrives.

Owners in Claremont and in Montclair, on either side of the Mills Avenue county line, work from the same January 1. What differs between the two counties is everything around it.

What does section 2192 say, phrase by phrase?

• "Except as otherwise specifically provided." The statute leaves room for other rules. Some events carry their own dates. The State Board of Equalization's guide to residential appeals, for example, describes a supplemental assessment, an assessment of fair market value as of the date a change in ownership occurs or new construction is completed. Those events are valued as of their own dates.
• "All tax liens." A lien is a legal claim against the property that secures payment of a debt, here the property tax.
• "Attach annually." A new lien attaches every year. Each year's tax has its own lien date.
• "As of 12:01 a.m." One minute after midnight. The moment falls on New Year's Day, not on the evening of December 31.
• "On the first day of January preceding the fiscal year." The January 1 comes before the fiscal year the tax pays for. The date is fixed first; the bill follows later.
• "For which the taxes are levied." The fiscal year whose tax this lien secures.

Why does a date for a lien also fix a date for value?

Because section 51 ties the two together. On each lien date, the taxable value of real property is the lesser of two numbers: its factored base year value, the value set when the property last changed hands or was newly built, compounded each year by an inflation factor the statute caps, and its full cash value as of the lien date. Section 110 defines full cash value as the price the property would bring if exposed for sale on the open market, between a buyer and seller who each know its uses and neither of whom can take advantage of the other.

The State Board of Equalization's guide puts the consequence in one line: for decline-in-value appeals, the lien date is the valuation date. The county's assessed value, the value the Assessor enrolls under those rules, is not an appraisal. It is a tax figure tied to January 1, and any evidence offered against it has to speak to the same January 1.

What is the lien date not?

• Not the date on the bill. The guide notes that tax bills are generally sent out in October, so an owner usually first sees the enrolled value many months after the date it measures.
• Not a filing deadline. Informal reviews and formal appeals have their own periods, set by each county and published on its pages. Those periods are not stated here. Confirm the current period on the Los Angeles County Assessor's decline-in-value page, the Los Angeles County Assessment Appeals Board page, the San Bernardino County Assessor's appeals page or the San Bernardino County Clerk of the Board page.
• Not the hearing date or the inspection date. A hearing, or an appraiser's visit, may come many months later. Neither moves the date the value is measured.

Is the lien date the same on both sides of Mills Avenue?

Yes. Section 2192 is state law, so a postwar ranch house in Claremont just west of Mills Avenue and a similar house in Montclair just east of it share the same January 1. Mills Avenue is Montclair's western boundary and the line between the counties, and almost everything else changes there.

Claremont sideMontclair side

Lien date

January 1, section 2192

January 1, section 2192

Who assesses

Los Angeles County Office of the Assessor

San Bernardino County Assessor-Recorder-County Clerk

Who hears formal appeals

Los Angeles County Assessment Appeals Board

San Bernardino County Assessment Appeals Board, through the Clerk of the Board

Informal step

Decline-in-value review with the Assessor

Informal review with the Assessor, which the Assessor encourages first

Filing periods

Set and published by the county

Set and published by the county

The Claremont area page and the Montclair area page describe the housing on each side. For how the two counties run their reviews and appeals, see the guide to property tax appeals on the Los Angeles and San Bernardino county line.

What should an owner keep from around January 1?

Because the question is always about one morning in January, records from around that morning carry weight.

• Dated photographs of the house, inside and out, especially of anything worn, damaged or unfinished.
• Repair estimates, invoices and inspection reports dated near January 1.
• Permits and final sign-offs for additions, garage conversions or an ADU, showing what was complete on that date.
• Purchase documents, if the house was bought shortly before or after January 1; a sale of the house itself is evidence a board will ask about.
• The assessment notice or tax bill and the assessor's parcel number.

How does the lien date shape an appraisal?

It sets the effective date, the date the opinion of value applies to. A tax appeal appraisal is usually a retrospective appraisal, an appraisal whose effective date is in the past, because it is written after January 1. Its sales are chosen for that date: the State Board of Equalization's guide says sales dated more than 90 days after the valuation date cannot be admitted. Why the effective date is the lien date covers that in detail, and decline in value (Prop 8) in plain words covers section 51. Every article in this series is collected under property tax appeals on the county line.

The appraisal is an independent opinion of market value as of that date. It is not a prediction of what the Assessor or the board will decide, and nothing is said about the value before the work is done.

Next step

If you are preparing a review or an appeal in Claremont, Montclair or a neighboring city, read how the property tax appeal appraisal is scoped and tell us which year's January 1 is in question, or call (909) 324-6122. The fee is set by the scope of the assignment and quoted before work begins, and it does not depend on the value.

Sources

• California Revenue and Taxation Code section 2192 (lien date): https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=RTC&sectionNum=2192 (accessed October 30, 2026)
• California Revenue and Taxation Code section 51 (taxable value on each lien date): https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=RTC&sectionNum=51 (accessed October 30, 2026)
• California Revenue and Taxation Code section 110 (full cash value): https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=RTC&sectionNum=110 (accessed October 30, 2026)
• California State Board of Equalization, Publication 30, Residential Property Assessment Appeals: https://www.boe.ca.gov/proptaxes/pdf/pub30.pdf (accessed October 30, 2026)
• Los Angeles County Office of the Assessor, decline in value: https://assessor.lacounty.gov/tax-relief/decline-in-value (accessed October 30, 2026)
• San Bernardino County Assessor-Recorder-County Clerk, assessment appeals and informal reviews: https://arc.sbcounty.gov/assessment-appeals/ (accessed October 30, 2026)

Gordon Hall, California Certified Residential Real Estate Appraiser, BREA No. AR003877 (lookup: https://www2.brea.ca.gov/breasearch/faces/party/view.xhtml?id=23601). Reports are prepared in conformity with the Uniform Standards of Professional Appraisal Practice (USPAP). Nothing here is legal or tax advice; admissibility is always the court's decision.