1. The Tax Bill Reveals Which Charges Can Be Challenged
A larger bill does not establish an incorrect assessed value. First separate valuation disputes from charges another agency must review.
Assessed Value, Tax Rates, and Direct Assessments
The Los Angeles County Assessor determines taxable values and handles exemption claims. The Auditor-Controller calculates taxes using the general 1% levy, applicable voter-approved debt rates, and direct assessments. The Treasurer and Tax Collector issues bills and receives payments. A disputed sewer or lighting charge generally belongs with the imposing agency, not the Assessment Appeals Board. These are California and local tax matters, not IRS assessments.
Annual, Supplemental, and Business Property Bills
Annual secured bills cover real property. Supplemental assessments may follow purchases or new construction; unsecured bills can cover taxable business equipment. Check the Assessor's Identification Number (AIN), tax year, valuation notices, and earlier bills. A valuation challenge requires different evidence from a duplicate-payment complaint.
2. Assessment Evidence Establishes the Grounds for Review
California's Proposition 13 generally establishes a base-year value after a qualifying ownership change or new construction. Proposition 8 permits a temporary reduction when market value on January 1 falls below the factored base-year value. An increase alone does not prove error.
Comparable Sales Must Support the January 1 Value
A lower asking price alone does not prove overassessment. Compare sales near the January 1 lien date, accounting for differences in condition, size, location, and permitted use. For commercial property, leases, vacancy, expenses, and capitalization assumptions may matter. When market value recovers, a Proposition 8 assessment can rise more than 2%, though generally not above the factored base-year value absent another reassessment event.
Ownership Changes and Exemptions Require Separate Analysis
The Homeowners' Exemption reduces the taxable assessed value of an eligible principal residence by $7,000. It does not subtract $7,000 from the tax owed. Under Proposition 19, certain transfers of family homes or farms may avoid full reassessment, subject to statutory eligibility and filing rules. A child receiving a family home must meet principal-residence and exemption-claim requirements to qualify. Inherited property tax issues require deed, occupancy, and transfer-date records.
Business Valuations Must Separate Taxable and Intangible Assets
Machinery and equipment may be taxable, while business inventory held for sale is generally exempt. Revenue and Taxation Code §212(c) excludes intangible assets from property taxation. But assessors may assume intangible rights needed for the productive use of taxable property. The question is whether an appraisal attributes independent brand, goodwill, or enterprise value to taxable assets.
3. Assessment Appeals Depend on Notice Type and Filing Date
Owners may request an Assessor review or file a formal appeal with the independent County Assessment Appeals Board. Each route has distinct filing requirements.
An Informal Assessor Review Is Not a Formal Appeal
For the 2026–2027 tax year, the Assessor accepts decline-in-value applications from July 2 through November 30, 2026. A decline-in-value review addresses market value; errors in property records may require a separate correction request. Do not assume an informal request preserves formal appeal rights. A pending review is not the same as a filed real property tax assessment appeal.
Regular and Supplemental Assessments Carry Different Deadlines
The Los Angeles County regular assessment appeal period runs from July 2 through November 30 each year. Supplemental, adjusted, and escape assessments generally require filing within 60 days of the mailing date printed on the notice or tax bill, or its postmark date, whichever is later. Use County form AAB-100 or its online filing system. The nonrefundable filing fee is $46, with hardship waivers available. Keep the envelope and notice to establish the filing date.
The Hearing Record Affects Later Court Options
An attorney may review the appraisal, evidence, and Assessor's position, then prepare filings and present a hearing record. The board may lower, retain, or raise an assessment based on the record. A later refund action in California Superior Court generally requires payment of the disputed tax and compliance with applicable administrative and refund-claim procedures under Revenue and Taxation Code §§5097, 5140, and 5142. An adverse hearing result does not bypass those requirements.
4. Property Sales Can Produce Bills Beyond Closing Estimates
Escrow allocations and County tax collection answer different questions. A sale may also trigger a new assessed value and supplemental billing after the transaction closes.
An Escrow Credit Is Not Proof of County Payment
A closing statement may divide estimated annual taxes between buyer and seller without sending that amount to the Treasurer and Tax Collector. Compare the statement with the County payment history, particularly when the annual bill was unavailable during escrow. Commercial real estate purchase agreements may allocate later tax liabilities between the parties, but their terms do not cancel an unpaid County bill.
Supplemental Taxes Require Separate Payment Checks
A reassessment after purchase can generate a supplemental secured bill in addition to annual taxes. Mortgage impound accounts generally do not pay these supplemental bills automatically. Annual secured installments are due November 1 and February 1, becoming delinquent after December 10 and April 10, respectively, subject to applicable calendar adjustments. Filing an assessment appeal does not suspend tax payments. Review the payment instructions and deadlines on each bill to avoid penalties.
10 Nov, 2026
