Alameda County Property Assessor 2026: Search & Tax Records

by
Alameda County California Property Records Navigator

Find Alameda County APNs, Assessed Values and 2026–27 Property Taxes

The Alameda County Assessor determines taxable property values throughout Oakland, Berkeley, Fremont, Hayward, Dublin, Pleasanton, Livermore, Alameda, San Leandro and the rest of the county. The Treasurer-Tax Collector separately issues and collects secured, supplemental and unsecured property taxes, while the Clerk-Recorder maintains legal deeds and other recorded real-property documents.

This 2026 guide shows how to locate a property by address or Assessor’s Parcel Number, understand Proposition 13 base-year value, check a current tax bill, distinguish annual taxes from supplemental taxes, claim the Homeowners’ Exemption, request a Proposition 8 decline-in-value review, use Proposition 19 where applicable, file a 2026 assessment appeal before September 15 and research deeds or liens.

Find APN, parcel map and assessed values
Decode Proposition 13 and supplemental bills
Pay secured tax with free online e-check
2026 regular appeal deadline: September 15
Search Property Assessment Open Parcel Viewer Look Up / Pay Taxes File Assessment Appeal
County Assessor Phong La
Assessor telephone 510-272-3787
Treasurer-Tax Collector Henry C. Levy
Regular appeal deadline September 15, 2026
Last reviewed August 7, 2026
Current August 2026 status

The 2026–27 Assessment Roll Is Set—and the Appeal Window Is Open

If you disagree with your 2026 regular assessment, this is the important window. Alameda County accepts regular-roll Assessment Appeal Applications from July 2 through September 15. As of August 7, 2026, that filing period is open.
January 1, 2026 This is the annual lien date—the date on which taxable property is assessed for the 2026–27 roll.
July 1 The Assessor delivers the annual assessment roll to the Auditor-Controller and the new assessment-roll year begins.
Mid-July Alameda County’s calendar identifies mid-July as the annual mailing period for assessment notices to real-property owners.
Do not wait for the October tax bill if your dispute is about value. The deadline-protected action for a regular 2026 assessment is an Assessment Appeal Application filed by September 15.
Tax payment is later. The annual secured bill is normally issued in the fall, but assessment appeals happen before the first installment becomes delinquent.
Use the correct Alameda County office

Assessor, Tax Collector, Appeals Board and Clerk-Recorder Do Different Work

County Assessor

  • Assessed land and building value
  • Assessor’s Parcel Number
  • Parcel maps
  • Exemption values
  • Tax Rate Area code
  • Property use code
  • Prop 13 base-year assessment
  • Supplemental assessment

Treasurer-Tax Collector

  • Secured tax bills
  • Supplemental tax bills
  • Unsecured taxes
  • Payment status
  • Online payments
  • Prior-year delinquency
  • Tax default
  • Receipts

Assessment Appeals

  • Formal value appeals
  • Regular-roll appeals
  • Supplemental appeals
  • Hearing scheduling
  • Agent authorization
  • Hearing documents
  • Board findings

Clerk-Recorder

  • Recorded deeds
  • Deeds of trust
  • Liens
  • Reconveyances
  • Official Public Records
  • Recorded document copies
  • Legal property descriptions
An Assessor record is not proof that the tax was paid and a tax bill is not proof of legal title. Use each office for its own record.
California works differently from Tennessee. Proposition 13 controls Alameda County’s base-year assessment system. For a Tennessee comparison, see the Bradley County Property Assessor guide.

Choose the Alameda County Property Task You Need

Find a parcel Search by property address or APN and save the Assessor’s Parcel Number.
Check assessed value Review land, building, exemption and total assessed values.
Check taxes Search secured, supplemental, unsecured or prior-year tax records.
Appeal the 2026 roll File the regular assessment appeal no later than September 15, 2026.
Check reassessment Determine whether a sale, transfer or construction event created a new base-year value.
Research deed/title records Move to the Clerk-Recorder for the actual recorded instrument.

Jump to Your Alameda County Property Task

Alameda County Assessment Record Field Decoder

Field What it means What to check
APN Assessor’s Parcel Number assigned to the parcel. Save it for tax, appeal, map and supplemental workflows.
Property Address Physical situs of the parcel. Do not confuse this with the owner’s mailing address.
Assessed Land Value Taxable value allocated to land. Review along with improvements and base-year history.
Building Value Taxable value allocated to improvements. New construction can create a separate new base-year component.
Exemption Applicable exemption amount reducing taxable assessed value. Confirm a Homeowners’ or other exemption appears when expected.
Total Assessed Value Taxable assessment used to calculate ad valorem property tax. This is not necessarily current market value.
Tax Rate Area Geographic taxing-area code. Special taxes and voter-approved charges can vary by area.
Property Use Assessor use classification. Verify the property has not been coded for the wrong use.
California Proposition 13

Why Alameda County Assessed Value Can Be Far Below Market Value

BASE
Base-Year Value

A purchase or other reassessable change in ownership generally establishes a new base-year value at fair market value.

≤2%
Annual growth limit

The Proposition 13 assessed value generally increases by no more than 2% per year, subject to the applicable inflation factor.

NEW
New construction

Qualifying new construction can be separately assessed at current market value and added to the existing assessment.

P8
Prop 8 restoration

A temporarily reduced assessment can rise by more than 2% as market value recovers, but not above the factored Proposition 13 value.

A 10%, 20% or larger increase is not automatically illegal. It may result from a change in ownership, new construction or restoration of a prior Proposition 8 reduction.
California property-tax framework

How Alameda County Property Tax Is Calculated

Taxable assessed value Prop 13 / Prop 8 value after applicable exemption
×
1% base tax Proposition 13 general levy
+
Other charges Voter-approved debt, special taxes and assessments
Simple example: if the taxable assessed value after exemptions were $700,000, the Proposition 13 base 1% component would be $7,000 before voter-approved bonded debt, direct assessments or other parcel-specific charges.
Do not use 1% as an exact final bill. Alameda County’s actual secured tax bill can contain additional voter-approved or special charges tied to the property’s Tax Rate Area.
2026–27 secured property-tax year

Alameda County Assessment and Payment Calendar

Lien date Property is assessed as of 12:01 a.m. for the annual roll.
Exemption deadline Regular filing deadline for several exemptions, including Homeowners’ and Disabled Veterans’.
Appeals open First day to file a regular assessment appeal.
Appeal deadline Last regular filing day for the 2026 annual roll.
First installment cutoff Last day to pay the first secured installment without penalty.
Second installment cutoff Last day to pay the second secured installment without penalty.
First installment Due November 1; becomes delinquent after December 10 unless a weekend/holiday rule shifts the statutory deadline.
Second installment Due February 1; becomes delinquent after April 10, subject to applicable weekend/holiday rules.
Supplemental tax bills do not necessarily follow these dates. Read the due dates printed on each supplemental bill.
Common surprise after purchase or construction

Alameda County Supplemental Assessments Explained

Change occurs Property changes ownership or qualifying new construction is completed.
Assessor reappraises A new base-year value is established for the reassessable portion.
Supplemental notice The Assessor mails a Notice of Supplemental Assessment.
Separate tax bill The Tax Collector later issues a prorated supplemental bill or refund.
Supplemental means additional to the annual bill. It covers only the change in assessed value and is generally prorated from the first day of the month after the qualifying event through the end of the fiscal year.
Your mortgage lender may not pay it. Alameda County explains that supplemental tax bills are mailed directly to the owner rather than to the lender. Do not assume escrow will automatically handle the bill.
If the new value is lower: a qualifying supplemental reassessment decrease can produce a one-time supplemental refund after the regular bill is paid.
Read the Official Supplemental Assessment Guide Review the notice, proration rules, bill timing and examples before paying or appealing.
Reduce taxable assessed value when eligible

Alameda County Homeowners’ and Other Exemptions

Homeowners’ Exemption Qualifying owners who occupy the property as their principal residence on January 1 can receive a $7,000 reduction in taxable assessed value.
Typical tax savings Alameda County estimates the $7,000 Homeowners’ Exemption saves approximately $70–$80 per year.
Disabled Veterans’ Exemption A separate California exemption can provide significantly larger benefits when disability and eligibility requirements are met.
The regular February 15, 2026 exemption filing date has passed. Alameda County’s calendar also identifies December 10 as the late-claim deadline for certain homeowner, veteran and disabled-veteran exemption filings, with reduced benefit rules applying to late claims.
Need a Homeowners’ claim form? The Assessor asks qualifying property owners to call the Homeowners’ Exemption unit at 510-272-3770 for the system-generated claim form tied to the parcel.
Review Alameda County Exemptions Check Homeowners’, Disabled Veterans’, Veterans’ and other available exemption categories.
Decline in Market Value

When Proposition 8 Can Temporarily Lower a 2026 Assessment

The test Compare the property’s January 1 market value with its factored Proposition 13 base-year value.
Lower value wins If market value is below the factored base value, the Assessor must use the lower market value for that year.
Temporary reduction Proposition 8 value is reviewed each year and can rise as market value recovers.

Evidence the Assessor specifically wants

  • APN
  • Your January 1, 2026 value opinion
  • Comparable property sales
  • Sale dates near January 1
  • Comparable sales no later than March 31
  • Property-condition documentation
  • Income data for applicable commercial property
  • Current Assessor notice
Do not let an informal review replace a formal appeal deadline. If you still disagree with the 2026 annual assessment, file the Assessment Appeal Application by September 15.
Request a Decline-in-Value Review Prepare the APN and comparable-sale evidence before starting the owner e-form.
California Proposition 19

Base-Year Transfers and Family Transfers in Alameda County

Age 55+ / severely disabled An eligible homeowner can transfer a qualifying principal-residence base-year value to a replacement principal residence anywhere in California.
Up to three transfers Proposition 19 allows qualifying age/disability base-year transfers up to three times.
Parent-child rules changed Parent-child and grandparent-grandchild exclusions are narrower under Proposition 19 and generally focus on a qualifying family home used as a principal residence.
A more expensive replacement home can still qualify. Proposition 19 allows transfer of the old base value with an adjustment for the portion of the replacement property above the applicable equal-or-lesser-value threshold.
Do not assume an inherited home automatically keeps the parent’s assessment. Proposition 19 changed the family-transfer rules beginning in 2021.
Review Alameda County Proposition 19 Check base-year transfer and family-transfer requirements before recording or filing a claim.
Time-sensitive: filing open now

How to File an Alameda County 2026 Assessment Appeal

Regular assessment appeal deadline: September 15, 2026. Alameda County’s regular filing period runs July 2 through September 15.
Check the assessment Verify APN, assessed value, property facts and exemption status.
Build evidence Determine your supported January 1 market value and comparable sales.
File by Sep. 15 Submit the Assessment Appeal Application to the Clerk of the Board.
Prepare for hearing Upload or organize evidence and follow the assigned hearing instructions.
Processing fee: Alameda County currently identifies a nonrefundable $50 per-parcel Assessment Appeal Application processing fee. A fee-waiver request form is also published by the Appeals Unit.
Supplemental and escape assessments use a different deadline. The Assessor states those appeals generally must be filed within 60 days of the Notice of Supplemental Assessment or Notice of Enrollment of Escape Assessment, using the notice/postmark rule stated by the county.
Appealing does not suspend your tax-payment obligation. Pay the tax bill on time while the value appeal is pending to avoid penalties; refund procedures apply later if the assessment is reduced.

Evidence checklist

  • APN
  • 2026 assessment notice
  • Owner’s value opinion
  • Comparable arm’s-length sales
  • Independent appraisal
  • Property-condition photos
  • Repair estimates
  • Building-size corrections
  • Income/expense evidence for income property
  • Relevant sale or construction documents
“I am reviewing Alameda County APN __________ for the 2026–27 assessment roll. The enrolled value is __________, and my supported January 1, 2026 market value is __________. My evidence includes __________. I want to make sure my regular Assessment Appeal Application is complete before September 15.”
Assessment Appeals Unit Open the online appeal application, forms, fee-waiver form and hearing resources. Assessor Appeal Guidance Review regular, supplemental and escape-assessment filing periods.
Alameda County Clerk-Recorder

How to Search Deeds, Liens and Official Property Records

1853 to present Alameda County’s official real-property records date back to the county’s incorporation in 1853.
1969 to present Records from 1969 forward are electronically indexed and can be searched using the county’s public-record system.
Before 1969 Earlier indexes are on microfilm and must be researched in person at the Clerk-Recorder’s Office.
Start with the property assessment record. Copy the APN, address and any transfer information you already know.
Open Official Public Records. Use the Alameda County Official Public Records portal.
Search the parties or known document information. Recorded real-property indexes are organized around parties and recorded instrument information.
Use the instrument number for a copy request. The county online ordering system accepts the recorded instrument number.
Check later records. Finding a deed of trust or lien does not tell you whether a later reconveyance, satisfaction or release was recorded.
Use title professionals for legal certainty. Public record access is not an insured title search or legal opinion.
Official Public Record copy Current published fee
Plain copy $3.50 per page
Certified copy $4.50 first page; $3.50 each additional page
Online order convenience fee $2.00 per online order
Recorder office: 1106 Madison Street, Oakland, CA 94607. Local telephone 510-272-6362; toll-free 888-280-7708.
Business Personal Property

Alameda County Business Property Uses a Different Assessment Workflow

What is included Furniture, fixtures, equipment, computers and other taxable tangible assets used by a business can be assessed.
April 1 Business Personal Property statements such as Form 571-L are due annually by April 1.
May 7 Alameda County’s property-tax calendar identifies May 7 as the last filing date before the 10% late-filing penalty.
Do not apply a homeowner Prop 13 workflow to business equipment. Alameda County states that business personal property is assessed at fair market value as of January 1 each year.
Business Personal Property contact 510-272-3836
AssessorBPP@acgov.org

Alameda County Property Checklist by Situation

Situation Records to verify Best next action
Buying a home APN, assessed value, current secured taxes, deed, supplemental-tax estimate and exemptions. Budget for both annual tax and a possible supplemental bill.
Recent buyer Prior roll value, purchase price, Notice of Supplemental Assessment and supplemental bill. Do not assume mortgage escrow will pay the supplemental bill.
Longtime homeowner Prop 13 base value, annual factored value and Homeowners’ Exemption. Investigate any increase above the normal limit.
Market value fell January 1 value, comparable sales and current factored base value. Request Prop 8 review and preserve the Sep. 15 appeal deadline.
Owner age 55+ Original principal residence, replacement home and purchase/sale dates. Review Prop 19 base-year transfer before filing.
Inherited family home Transfer date, family relationship, principal-residence status and value. Do not assume the old Prop 13 assessment automatically transfers.
2026 value dispute Assessment notice, APN, January 1 evidence and comparables. File the regular appeal by Sep. 15, 2026.
Title or lien research APN, party names, deed/instrument number and later recorded documents. Use Clerk-Recorder Official Public Records.

Alameda County Property Offices, Phones and Map

Alameda County Assessor Phong La
1221 Oak Street, Room 145
Oakland, CA 94612
510-272-3787
Toll-free: 800-660-7725
Lobby: 9 a.m.–4:30 p.m., Monday–Friday
Dublin Assessor Satellite 7600 Dublin Blvd, #270
Dublin, CA 94568
510-272-3787
9 a.m.–4:30 p.m., Monday–Friday
Treasurer-Tax Collector Henry C. Levy
1221 Oak Street, Room 131
Oakland, CA 94612
510-272-6800
Call center / office: 8:30 a.m.–4:30 p.m.
Clerk-Recorder 1106 Madison Street
Oakland, CA 94607
510-272-6362
Toll-free: 888-280-7708
Assessment Appeals Unit: Clerk of the Board of Supervisors, 1221 Oak Street, Oakland. Appeal help: 510-272-3854.

Alameda County Property Search Problems and Fixes

Problem Practical fix Correct office
Do not know the APN Search Property Assessment Information by address, then save the APN. Assessor
Cannot find owner name online Alameda County intentionally does not publish owner names online; call/email the Assessor or visit the public records counter. Assessor
Need legal ownership proof Obtain the recorded deed rather than relying only on assessment information. Clerk-Recorder
Assessed value is far below sale estimates This can be normal under Prop 13’s base-year system. Assessor
Assessment rose more than 2% Check for ownership change, new construction or Prop 8 restoration. Assessor
Bought home and received another bill Determine whether it is a supplemental bill resulting from the ownership change. Assessor / Tax Collector
Mortgage company did not pay supplemental tax Supplemental bills are mailed directly to the owner; confirm payment responsibility immediately. Tax Collector
Property worth less than assessed value Submit Prop 8 evidence and preserve the Sep. 15 regular appeal deadline. Assessor / Appeals
Need current tax payment status Use the Treasurer-Tax Collector tax database, not the assessment page. Tax Collector
Want to avoid online payment fee Pay by e-check; Alameda County currently lists no convenience fee for online e-check. Tax Collector
Mailing check close to deadline Allow extra time or request manual USPS postmark; county warns of changed postmark processing rules. Tax Collector
Parcel-map line looks wrong Do not treat the online parcel map as a legal survey. Assessor / Surveyor
Need deed from before 1969 Research the microfilm index in person at the Clerk-Recorder. Clerk-Recorder
“I am researching Alameda County APN __________ at __________. My question concerns the 2026–27 assessed value, Proposition 13 base year, Prop 8 review, supplemental assessment, Homeowners’ Exemption, tax bill, September 15 appeal deadline or recorded deed. Please confirm which record or filing controls my next step.”
Official final-action routes

Alameda County Property Search and Tax Action Center

Keep the APN, property address, assessment notice, tax year and any supplemental notice or recorded instrument number available before switching between county systems.

Search Assessment Find APN, assessed values, exemptions and parcel information. Check / Pay Tax Search secured, supplemental, unsecured and prior-year taxes. File 2026 Appeal Complete the regular-roll appeal before September 15. Search Recorded Documents Research deeds and other official public records.
10 Alameda County-specific answers

Alameda County Property Assessor Search and Tax FAQs

1. How do I search Alameda County property records in 2026?

Start with Alameda County Assessor Property Assessment Information and search by property address or Assessor’s Parcel Number. Save the APN, then review the parcel map, assessed land and building values, exemption value, total assessed value, Tax Rate Area and property-use information.

2. Who is the Alameda County Assessor in 2026?

Phong La is the Alameda County Assessor. The main Assessor office is at 1221 Oak Street, Room 145, Oakland, CA 94612. The main telephone number is 510-272-3787 and public lobby hours are generally 9 a.m. to 4:30 p.m. Monday through Friday except holidays.

3. Can I search an Alameda County property owner by name online?

The Assessor does not publish owner names on its public website. Ownership information for a limited number of properties can be requested by telephone or email, and public ownership records can also be reviewed at the county office. For legal proof of ownership, use the recorded deed through the Clerk-Recorder.

4. How does Proposition 13 affect an Alameda County assessment?

Proposition 13 generally establishes a base-year value when property is purchased or otherwise reassessed and limits annual increases in that assessed value to no more than 2% based on the applicable inflation factor. A change in ownership, new construction or restoration of a temporary Proposition 8 reduction can cause a larger increase.

5. What is the Alameda County Homeowners’ Exemption?

A qualifying owner who occupies a home as the principal residence on January 1 can receive a $7,000 reduction in taxable assessed value. Alameda County estimates this typically saves about $70 to $80 per year in property tax.

6. When are Alameda County 2026–27 secured property taxes due?

The first secured-tax installment is due November 1 and must generally be paid by December 10 to avoid penalty. The second installment is due February 1 and must generally be paid by April 10 to avoid penalty. Weekend or legal-holiday rules can move statutory deadlines to the next business day.

7. What is an Alameda County supplemental property-tax bill?

A supplemental bill can result when a property changes ownership or qualifying new construction is completed. The Assessor establishes a new value for the reassessable portion and the Tax Collector later issues a separate prorated bill based only on the added value. Supplemental bills are in addition to the regular annual bill.

8. What is the Alameda County 2026 assessment appeal deadline?

Regular assessment appeals for the 2026 annual roll may be filed from July 2 through September 15, 2026. Supplemental and escape assessments use a separate deadline that is generally 60 days from the applicable assessment notice under the county’s stated notice/postmark rules.

9. How do I pay Alameda County property taxes without an online convenience fee?

Use an electronic check from a checking or savings account through Alameda County’s official online property-tax system. The county currently lists no convenience fee for e-check, while credit-card transactions carry a 2.3% convenience fee.

10. Where do I find an Alameda County deed or lien record?

Use the Alameda County Clerk-Recorder Official Public Records system. Records from 1969 to the present are electronically indexed, while records before 1969 must be searched in person using microfilm. The Clerk-Recorder is located at 1106 Madison Street in Oakland.

Official Sources and Editorial Verification

Alameda County Assessor Current Assessor Phong La, property services and office information. Property Assessment Information Official property-assessment and tax-information gateway. Assessor Parcel Viewer APNs, parcel maps, boundaries and parcel-map cautions. Proposition 13 Base-year assessment, 1% base tax and assessment-growth framework. Supplemental Assessments Change-in-ownership, new-construction and prorated supplemental billing. Property Tax Exemptions $7,000 Homeowners’ Exemption and other exemption programs. Treasurer-Tax Collector Secured, supplemental and unsecured tax payments and current mailed-payment notice. Property Tax Lookup Tax search, payment, free e-check and current card convenience fee. Assessment Appeals Online appeal application, processing fee, waiver form and hearing resources. Official Public Records Deeds and recorded-property research through the Clerk-Recorder.
Verification scope: current Assessor and Treasurer-Tax Collector, property-record fields, online ownership limitations, parcel maps, Proposition 13 rules, Proposition 8 review, Proposition 19, $7,000 Homeowners’ Exemption, supplemental assessments, 2026 regular appeal deadline, assessment appeal fee, secured tax due dates, e-check/card fees, Clerk-Recorder record availability, office addresses, phones and hours were reviewed for this update.

CountyPropertyAppraiser.org is an independent informational website. It is not affiliated with the Alameda County Assessor, Treasurer-Tax Collector, Assessment Appeals Board, Clerk of the Board of Supervisors, Auditor-Controller/Clerk-Recorder, California State Board of Equalization or any property-tax payment processor.

Assessed values, exemption status, tax rates, special assessments, payment balances, convenience fees, appeal requirements, office hours and online systems can change. Confirm time-sensitive information with the responsible official office before paying a tax bill, filing an appeal, transferring property or relying on a record for a legal transaction.

Last reviewed: August 7, 2026.

Slug: alameda-county-assessor-property-search

Leave a Comment

County Property Search, Homestead & Tax Help Toolkit

Use this free helper to find the right county office, prepare a property search, understand appraised value, review homestead exemption steps, and organize TRIM notice or tax bill questions before using official county websites.

Built for Florida county property guides
Helps users find official resources
No fake database or approval claim
Useful after every article

Find the Correct County Office

Property Appraiser, Tax Collector, Clerk, GIS, and VAB offices do different jobs. Pick your task below.

Quick rule: Property Appraiser = value, records, parcel details, exemptions. Tax Collector = bill and payment. Clerk/Recorder = deeds and recorded documents. VAB = formal value disputes.

Official Property Search Helper

Use this when a county article tells you to search by owner, address, parcel number, folio, PCN, STRAP, or alternate key.

Search tip: If address search fails, try only the house number and main street name. Avoid typing Street, Avenue, Road, Drive, unit numbers, or punctuation unless the official portal requires it.

Homestead Exemption Readiness Check

This helps homeowners prepare before filing through the official county Property Appraiser website.

Important: This is not an eligibility decision. The official county Property Appraiser decides approval, required documents, late filing options, and exemption status.

TRIM Notice & Value Review Helper

Use this to organize your questions before calling the Property Appraiser or preparing an appeal.

Your preparation checklist

Value term Simple meaning
Market value The appraiser’s estimate of the property’s value as of the assessment date.
Assessed value The value after limits or caps may be applied.
Exemptions Approved reductions such as homestead or other exemptions.
Taxable value The value used by taxing authorities after exemptions.

Property Tax Bill Direction Helper

The Property Appraiser values property, but the Tax Collector usually handles the actual bill and payment.

Florida timing reminder: Many Florida tax bills are mailed around November and become delinquent if unpaid after March 31. Always verify exact dates, discounts, and payment fees with the official county Tax Collector.

County Office Call Script Generator

Generate a simple call or email script so you can ask the right office the right question.