California Property Tax Appeal | 2026 Guide

Under Proposition 13, your factored base year value stays in place until a change in ownership or new construction occurs. Cal. Rev. & Tax. Code §60 defines a change in ownership as a transfer of a present interest in real property, including the beneficial use thereof, the value of which is substantially equal to the value of the fee interest. When that happens, the assessor sets a new base year value at the property's current market value as of the transfer date — usually the purchase price.

Cal. Rev. & Tax. Code §61 lists transfers that do count as a change in ownership, and §62 lists key exclusions that do not trigger reassessment, including:

• transfers between spouses or registered domestic partners;
• transfers that only change the method of holding title without changing proportional interests;
• certain transfers into and out of revocable trusts — note §61(h) provides a change in ownership occurs when a revocable trust becomes irrevocable and interests vest in someone other than the trustor or the trustor's spouse/partner.

Why this matters for an appeal:

• A wrongly-triggered reassessment is appealable. If the assessor reappraised based on a transfer you believe was excluded (e.g., a spousal transfer or a title-method change), you can dispute that a change in ownership occurred — often via a supplemental (§75.31) or escape (§1605) assessment appeal.
• File the change-in-ownership statement on time. Doing so preserves favorable burden-of-proof treatment if value is later contested.

Proposition 19 separately narrowed the parent-child/grandparent-grandchild exclusion (see the state BOE Proposition 19 page), so inherited-property transfers now trigger reassessment far more often than before.

On the BOE-305-AH application there is a box to state whether the appeal is intended to constitute a claim for refund. Whether you check it changes your post-decision timeline under Cal. Rev. & Tax. Code §5097.

Here is how §5097 works after the board rules:

• If you do designate the application as a claim for refund, the appeal application itself serves as the refund claim — you preserve the right to file suit for a refund without a separate filing step.
• If you do not designate it, §5097 still lets you file a claim for refund within one year after the appeals board makes its final determination on your application. But if the board's decision notice advises you to file within six months, that shorter clock applies.

Why designate it:

• A claim for refund is the gateway to superior court. California has no administrative appeal of an AAB decision to the state BOE; your only escalation is a refund action in superior court, and you generally must have a valid refund claim on file first (you must file suit within the limitations period after the claim is denied or deemed denied).
• It avoids missing the post-decision window. Homeowners who win a reduction but forget to file a refund claim can lose the money already paid on the higher assessment.

Practical advice: check the claim-for-refund box on the application unless you have a specific reason not to. It costs nothing and protects your downstream rights. The state BOE assessment appeals page and Publication 30 both note the refund-claim election.

An escape assessment is a back-assessment the county adds when value that should have been on the roll was missed — for example, an unrecorded change in ownership, completed new construction that was never picked up, or a reappraisable event the assessor learns of late. It can reach back several years and arrive as a surprise tax bill.

The appeal clock is short. Under Cal. Rev. & Tax. Code §1605, an application to appeal an escape assessment must be filed with the clerk of the board within 60 days of the date you were notified — and receipt of a tax bill based on the escape assessment counts as that notice. The regular July–November §1603 period does not govern escape assessments.

What to do:

• File a BOE-305-AH within the 60-day window — diary the date from the notice or bill immediately.
• You can challenge both the value and the underlying event. Often the dispute is whether a reappraisable change in ownership or new construction actually occurred under Cal. Rev. & Tax. Code §60, not just the dollar amount.
• Burden of proof can favor you. Under Cal. Rev. & Tax. Code §1610.8, for an escape assessment where you supplied the assessor all required information — and the escape did not result from your failure to file required documents — the assessor carries the burden of proof.
• Pay or arrange the bill to avoid penalties while the appeal is pending.

The state BOE assessment appeals page covers the general filing mechanics; §1605 controls the escape-assessment deadline.

An exchange of information is a pre-hearing discovery tool under Cal. Rev. & Tax. Code §1606. It forces both sides to disclose the basis of their opinion of value before the Assessment Appeals Board hearing, so neither party is ambushed.

How it works:

• Who can initiate: When the assessed value is $100,000 or less, only the applicant may request an exchange. When it exceeds $100,000, either the applicant or the assessor may request one.
• What you disclose: Each side states the basis of its value opinion. For a comparable-sales approach, you must identify each comparable property with enough certainty — assessor's parcel number, street address or legal description, approximate sale date, zoning, price paid, and terms of sale.
• Timing: A request may accompany the BOE-305-AH application or be filed any time up to 30 days before the hearing.
• At the hearing: If you initiated an exchange, you generally may introduce only the evidence and comparables you disclosed — but you can rebut new matter the assessor raises. This is why the exchange is strategic: it locks in the assessor's comps and prevents surprises.

For most homeowners with assessments above $100,000 (common in California), an exchange of information is worth requesting: it reveals the assessor's comparable sales early so you can prepare rebuttals. The state BOE assessment appeals page and Publication 30 describe the procedure, and §1606 is the controlling statute.

California assesses property under Proposition 13 rather than annual market value. When you buy a home or complete new construction, the assessor sets a base year value — generally the purchase price or cost of construction. Each year after, that figure is multiplied by an inflation factor (the California Consumer Price Index change), but the factor is capped at 2% per year. The result is your factored base year value (FBYV).

The factored base year value matters for appeals because of the lesser-of rule in Cal. Rev. & Tax. Code §51: the taxable value enrolled each year is the lesser of (a) the factored base year value or (b) the property's current market (full cash) value on the January 1 lien date. The state BOE decline-in-value page confirms the assessor enrolls the lower of those two numbers.

Why this drives strategy:

• If market value is above the FBYV, you are already protected by Prop 13 — there is usually nothing to appeal, because you are taxed on the lower factored base year value.
• If market value has fallen below the FBYV, you are entitled to a temporary Proposition 8 reduction down to market value. This is the most common residential appeal in California.
• The FBYV is the ceiling. An appeal cannot lower your assessment permanently below the base year value, and a Prop 8 reduction can be restored toward the FBYV (faster than 2%/year) as the market recovers.

A new base year value is only triggered by a change in ownership or new construction under Cal. Rev. & Tax. Code §60 — which is why recent buyers are most likely to have a FBYV near current market and thus a viable Prop 8 case.

Many California counties offer an assessment hearing officer as a faster, less formal alternative to the full Assessment Appeals Board. Under Cal. Rev. & Tax. Code §1641.1, a county board of supervisors may authorize hearing officers to hear applications where the property is a single-family dwelling, condominium or cooperative, or a multiple-family dwelling of four units or less — regardless of value — or where the total assessed value on the current roll does not exceed $500,000.

For a homeowner this is usually the better venue:

• Most owner-occupied homes qualify by property type alone, so the $500,000 ceiling rarely matters for residential appeals.
• The hearing is typically shorter and less adversarial than a three-member board hearing, though the officer applies the same valuation law.
• The officer issues a recommendation or decision that the board adopts; in some counties either party can object and escalate to the full board.

Important limits:

• A hearing officer must be authorized by your county. Not every county uses them; check with the clerk of the board.
• The same value rules apply. The officer still determines full value under Cal. Rev. & Tax. Code §1610.8, including the assessor's burden of proof on an owner-occupied single-family dwelling — and the value can still be increased, not just reduced.
• You request the hearing-officer option on or with your BOE-305-AH application.

The state BOE assessment appeals page and county clerks of the board describe the local hearing-officer program.

California's lien date is January 1. The property's taxable status, ownership, and value for the coming fiscal year (July 1–June 30) are all determined as of that single date. This is the reference point for every appeal: when you argue your home is over-assessed, the question is what its full cash value was on January 1, not on the date you file or the date of the hearing.

The lien date anchors the lesser-of comparison in Cal. Rev. & Tax. Code §51: the assessor enrolls the lesser of your factored base year value or the market value as of the lien date. A Proposition 8 decline-in-value claim therefore stands or falls on comparable sales clustered around January 1 — sales months later that show a recovery (or a further drop) are generally less persuasive than sales near the lien date.

Practical implications for an appeal:

• Gather comps near January 1. The strongest evidence is arm's-length sales of similar properties closing in roughly the fourth quarter of the prior year through the first quarter of the assessment year.
• Mid-year events don't change the regular lien date — a purchase or new construction after January 1 instead triggers a supplemental assessment with its own §75.31 60-day appeal clock.
• The regular appeal window to challenge the lien-date value opens July 2 under §1603, roughly six months after the lien date, and closes September 15 or November 30 by county.

The state BOE assessment appeals page frames the appeal around the lien-date value.

Los Angeles County uses the November 30 closing date. The regular filing period under Cal. Rev. & Tax. Code §1603 opens July 2 and, because the L.A. County Assessor does not send an assessed-value notice to all secured-roll owners by August 1, the deadline extends to November 30 rather than September 15.

In Los Angeles County you file the BOE-305-AH Assessment Appeal Application with the Los Angeles County Assessment Appeals Board / Clerk of the Board, not with the assessor. The county also runs a decline-in-value (Proposition 8) path: if your market value on the January 1 lien date is below your factored base year value under Cal. Rev. & Tax. Code §51, you can request an informal review, but that request does not extend the November 30 formal-appeal deadline.

Key reminders for L.A. County owners:

• Confirm the date annually — November 30 applies as long as the August 1 universal-notice condition is unmet, which is the county's longstanding practice, but verify on the Clerk of the Board's published filing period each year.
• Pay the tax bill on time regardless of a pending appeal to avoid penalties.
• Supplemental assessments (after a purchase or new construction) carry their own 60-day appeal window under Cal. Rev. & Tax. Code §75.31, separate from the November 30 regular period.

The state BOE assessment appeals overview confirms the July 2 / September 15 / November 30 framework that L.A. County follows.

Proposition 19 (effective 2021) reshaped two California property-tax transfer rules, both administered through the state BOE Proposition 19 page. The piece most relevant to homeowners is the base year value transfer, codified at Cal. Rev. & Tax. Code §69.6.

Under §69.6, a person who is over 55, severely and permanently disabled, or a victim of a wildfire or natural disaster, and who resides in a home eligible for the homeowners' or disabled veterans' exemption, may transfer the factored base year value of that home to a replacement principal residence purchased or newly constructed anywhere in California within two years of selling the original. Eligible owners may use this transfer up to three times, regardless of any earlier transfer under the old Propositions 60/90 or 110.

Why this matters for assessments and appeals:

• It can reset what your "correct" assessed value should be. If you qualified for a Prop 19 transfer but the assessor enrolled a full-market base year value on your replacement home instead of your transferred factored base year value, that is a basis to seek correction — file the transfer claim with the assessor first.
• If the replacement home costs more than the original, the difference is added to the transferred value, so the new base year value is the transferred value plus the excess.
• Proposition 19 also tightened the parent-child and grandparent-grandchild exclusion (via §63.2), narrowing inherited-property reassessment relief — a separate issue from the value transfer.

A Prop 19 dispute usually turns on eligibility and the transfer claim, handled by the assessor, rather than a standard market-value BOE-305-AH appeal. If the assessor denies the transfer or miscomputes the value, escalate through the assessment appeal and refund process.

Proposition 8 (1978) added Cal. Rev. & Tax. Code §51, which requires the assessor to enroll the lesser of (a) your property's factored base year value — the Prop 13 base value adjusted by up to 2% per year — or (b) its current market (full cash) value as of the January 1 lien date. When the market value falls below the factored base year value, you are entitled to a temporary reduction known as a Prop 8 decline-in-value assessment, explained on the state BOE decline-in-value page.

Many county assessors run an informal decline-in-value review on request — and some review properties automatically after a market drop — without requiring you to file a formal appeal. You typically submit two or three comparable sales near the January 1 lien date showing your home's market value is below the factored base year value. If the assessor agrees, the roll is lowered for that year.

Two things to know:

• Prop 8 reductions are temporary. The assessor can restore value year to year (up to the factored base year value) as the market recovers — increases are not capped at 2% while the property is in Prop 8 status, only at the factored base year ceiling.
• Informal review does not extend the appeal deadline. If the assessor declines or the lien date passes, you must still file a BOE-305-AH by your county's §1603 deadline to protect a formal appeal.

Prop 8 is the most common path for recently-purchased homes whose market value has slipped below the purchase-price-based base year value.

Cal. Rev. & Tax. Code §51 is the statute that operationalizes Proposition 13's value cap together with Proposition 8's relief. It states that for each lien date after the base year is set, the taxable value of real property is the lesser of:

1. its factored base year value — the Prop 13 base value adjusted by the annual inflation factor (capped at 2% per year), or 2. its full cash value (current market value) as of the January 1 lien date.

This lesser-of rule is the single most important concept for a California appeal:

• It protects you in a rising market. Even if your home's market value jumps, you are taxed on the lower factored base year value — there is usually nothing to appeal.
• It entitles you to relief in a falling market. When market value drops below the factored base year value, §51 requires the assessor to enroll the lower market figure — this is the Proposition 8 decline-in-value reduction described on the state BOE decline-in-value page.
• It defines what you must prove. To win a Prop 8 appeal you must show, with comparable sales near the lien date, that current market value is below the factored base year value the assessor enrolled.

Section 51 also explains why Prop 8 reductions are temporary: once market value recovers, the assessor restores the enrolled value year over year, never exceeding the factored base year value ceiling. The annual factor itself comes from the change in the California Consumer Price Index but is statutorily limited to 2%. Understanding §51 tells you whether you even have a case — if your factored base year value is already well below market, an appeal will not help and could expose you to an upward adjustment under §1610.8.

California's appeal deadline depends on your county. Under Cal. Rev. & Tax. Code §1603, the regular filing period opens July 2 and closes on one of two dates:

• September 15 — in counties where the assessor mails an assessed-value notice to all owners of real property on the local secured roll by August 1.
• November 30 — in counties where the assessor does not provide that notice to all owners by August 1.

The statute reads that the filing period runs "from July 2 to September 15, inclusive," and that "the last day of the filing period shall be extended to November 30" when the August 1 notice condition is not met. Per the state BOE assessment appeals page, most California counties fall into the November 30 group; a minority — including several large urban counties — use September 15.

Practical points:

• Confirm your county's date every year. A county can switch between the two dates annually depending on its notice practice, so do not assume last year's deadline. The clerk of the board or the county's appeals page publishes the current period.
• Weekend/holiday rule. If the final date falls on a Saturday, Sunday, or legal holiday, an application postmarked the next business day is timely.
• Supplemental and escape assessments have their own 60-day clocks that run independently of the July–November regular period.

Missing the deadline generally forfeits your formal appeal for that roll year, so file the BOE-305-AH early.

A supplemental assessment is issued when a property changes ownership or completes new construction mid-year, capturing the value change from the date of the event rather than waiting for the next January 1 lien date. Because it arrives off the normal cycle, it has its own appeal clock.

Under Cal. Rev. & Tax. Code §75.31, the supplemental notice must advise you of the right to an informal review and the right to appeal, and the appeal "shall be filed within 60 days of the date of mailing printed on the notice or the postmark date therefor, whichever is later." In counties that have adopted the relevant option (and in Los Angeles County), the 60 days runs from the date printed on the supplemental tax bill instead.

Key points:

• File a BOE-305-AH with the clerk of the board within that 60-day window — do not wait for the regular July–November period, which does not govern supplemental assessments.
• Late notice protection: if you did not receive the notice at least 15 days before the regular §1603 deadline, §75.31 lets you file within 60 days of the tax bill with an affidavit that the notice was not timely received.
• Stipulated error: if you and the assessor agree there is an error, an application may be filed within 12 months of notification.
• A supplemental assessment usually reflects a change in ownership or new construction, so the underlying dispute is often whether a reappraisable event actually occurred, not just the value.

The state BOE assessment appeals page covers the general filing mechanics.