Alameda County property tax starts with the 1% base rate set by California’s Proposition 13, then adds voter-approved bonds and local assessments that vary by city. Most homeowners pay a combined rate between roughly 1.13% and 1.34% of assessed value. Bills arrive annually and are paid in two installments, due November 1 and February 1.
This guide covers the current rates by city, the payment deadlines and penalties, how to look up and pay your bill online, what supplemental taxes catch new buyers off guard, and how to appeal an assessment you believe is too high.
How Alameda County Property Taxes Work
Property taxes are annual charges that local governments levy on real estate. In Alameda County, that revenue funds public schools, fire and police services, road and library maintenance, and a long list of local districts. For most owners, the tax bill is one of the higher recurring costs of homeownership, second only to the mortgage payment itself.
Your bill starts from your property’s assessed value. Under Proposition 13, the county sets that value at your purchase price when you buy, then raises it by no more than 2% per year for as long as you own the home. The tax itself is 1% of that assessed value, plus the voter-approved bonds and special assessments tied to your specific location. Add it all together and you get your effective rate.
The county calculates the bill by multiplying your assessed value by the combined rate for your Tax Rate Area, or TRA. Your TRA is set by your address and reflects which school bonds, city measures, and special districts apply to your parcel. Two homes on the same block can carry different rates if a bond covers one and not the other.
How Much Is the Alameda County Property Tax Rate?
The 1% base rate is fixed countywide. What moves the number is everything stacked on top: school district bonds, city bonds, and special assessments approved by local voters. The result is a combined rate that shifts from one city to the next.
The table below shows representative rates by city from the Alameda County Auditor-Controller’s most recent published tax rate book (fiscal year 2024-2025). These are typical figures for each city. Your exact rate depends on your parcel’s TRA, and rates adjust each year slightly as bonds are added or paid off.
| CITY | REPRESENTATIVE COMBINED RATE |
|---|---|
| Berkeley | 1.1327% |
| Livermore | 1.1348% |
| Fremont | 1.1537% |
| Alameda | 1.1663% |
| Castro Valley | 1.1791% |
| Hayward | 1.1842% |
| San Leandro | 1.2246% |
| Dublin | 1.2442% |
| Oakland | 1.3391% |
For a quick budgeting estimate on a purchase, many buyers use 1.25% of the price countywide, or closer to 1.34% in Oakland. To put that in dollars, a home assessed at $1,000,000 in the city of Alameda carries an annual tax of about $11,663 at the 1.1663% rate. The same assessed value in Oakland runs about $13,391. That gap is real money, and it belongs in your monthly payment math before you write an offer.
One item to watch in newer subdivisions is a Mello-Roos tax, a special assessment that funds infrastructure in certain districts and can push the combined rate meaningfully higher. To confirm the exact rate on a specific property, use the Alameda County Auditor-Controller’s tax rate search and enter the address or TRA.
Alameda County Property Tax Due Dates for 2026
Property taxes in Alameda County are billed once a year and paid in two installments. Bills are mailed in October.
| INSTALLMENT | DUE DATE | DELINQUENT AFTER |
|---|---|---|
| First Installment | November 1 | December 10 |
| Second Installment | February 1 | April 10 |
Miss the December 10 or April 10 deadline and a 10% penalty is added to the unpaid installment immediately. If December 10 or April 10 lands on a weekend or holiday, you have until 5 p.m. on the next business day. Not receiving a bill does not waive the deadline or the penalty, so track your dates even if the mail goes astray.
If your taxes are paid through an impound account, your lender pulls the money from your monthly escrow deposit and pays the county on your behalf. Review your annual escrow analysis to confirm the amount being collected matches the current bill, especially after a rate or assessment change.
How to Make Your Alameda County Property Tax Payment Online
The Alameda County Treasurer-Tax Collector accepts payments through its official online property tax portal. You can pay by electronic check at no cost, or by credit or debit card for a convenience fee of around 2.5%.
To pay online:
- Open the county’s property tax portal and choose whether you are paying secured or supplemental taxes.
- Search for your bill by parcel number (APN) or property address.
- Select the installment you want to pay.
- Choose e-check for no fee or a card for the convenience fee, then submit.
Save the confirmation number once the payment posts. You can also pay by mail with a check made out to the Treasurer-Tax Collector, or in person at 1221 Oak Street, Room 131, in Oakland. Payments totaling $50,000 or more across both installments must be sent by wire transfer.
How to Do an Alameda County Property Tax Lookup
Before you rely on any rate or bill figure, pull the actual record for the specific parcel. An Alameda County property tax lookup lets you verify the assessed value, the current amount due, payment history, and the parcel map for any address.
The Assessor’s property search lets you look up a parcel by address or APN to see the assessed value and parcel details. The Treasurer-Tax Collector’s lookup shows your current balance, prior-year history, and any supplemental bills. The county also offers an AC Property mobile app that combines the lookup and payment functions in one place.
For buyers, this step matters more than the citywide averages. The record tells you what the parcel is actually assessed at today and which special assessments apply, which is the number you want in your budget rather than a rule-of-thumb estimate.
Supplemental Tax Bills After You Buy
Supplemental taxes are the surprise that catches new Alameda County homeowners most often. When you buy, the county reassesses the property at its new value, which is usually your purchase price. If that new value is higher than what the prior owner was assessed at, you owe a supplemental bill for the difference.
The supplemental amount is prorated for the months left in the fiscal year, which runs July 1 through June 30, from your closing date. Buy between January 1 and June 30, and you may receive two supplemental bills, because the reassessment touches two fiscal years.
These bills arrive on their own schedule, often months after closing, and most impound accounts do not cover them. Set the cash aside so the supplemental tax bill does not blindside you. If you are working through the wider California mortgage process, factor supplemental taxes into your reserves along with your regular closing costs.
How to Appeal Your Alameda County Assessment
If your home is assessed for more than its market value, you have the right to appeal, and the process is more approachable than most owners assume. The Assessment Appeals Board reviews the evidence from you and the Assessor’s Office and sets the value.
An appeal makes sense when comparable homes in your area sold for less than your assessed value, when the Assessor worked from outdated data, or when a property-specific issue was not accounted for. The board weighs your property’s market value as of January 1, the lien date, so your comparable sales should sit close to that date.
Here is the path to file:
- Start with an informal review. Contact the Alameda County Assessor and provide comparable sales that support a lower value. Many cases resolve here without a formal hearing.
- Gather your evidence. Pull recent sales of similar nearby homes, and add an appraisal or photos where they help.
- File an Assessment Appeal Application with the Clerk of the Board of Supervisors at 1221 Oak Street, Room 536, in Oakland. A nonrefundable processing fee applies per application, so confirm the current amount when you file.
- Attend your hearing and present your case. The board can lower, keep, or in rare cases raise the value.
For a regular assessment, the filing window runs July 2 through September 15 each year. For a supplemental or escape assessment, you have 60 days from the date of the notice or bill. One thing to remember: you still have to pay your taxes on time while the appeal is pending. If the value is later reduced, the county issues a refund or a corrected bill.
Proposition 13 and Your 2% Cap
Proposition 13 is the reason a longtime Alameda County owner and a recent buyer on the same street can pay very different taxes. Once you buy, your assessed value resets to the purchase price, and from that point it can rise no more than 2% per year for as long as you own the home.
The cap holds until a reassessment event: a sale, a transfer of ownership, or new construction. That protection is one of the most valuable a California homeowner has. It also means the assessed value on a home held for decades can sit far below its current market value, which is exactly how the law is designed to work.
Exemptions That Lower Your Bill
A few exemptions reduce your assessed value and, with it, your tax. The most common is the Homeowners’ Exemption, which knocks $7,000 off the assessed value of an owner-occupied primary residence and saves roughly $70 a year. File the claim with the Assessor by February 15 to receive the full benefit for that year.
Alameda County also administers a Veterans’ Exemption, a larger Disabled Veterans’ Exemption, and Proposition 19 base-year transfers that let qualifying homeowners aged 55 and older, or those with a severe disability, carry their existing assessed value to a new home. If any of these fit your situation, the Assessor’s office can confirm eligibility and the current amounts.
Frequently Asked Questions
What is the property tax rate in Alameda County?
Alameda County property taxes start with the 1% Proposition 13 base rate, then add voter-approved bonds and special assessments tied to your Tax Rate Area. Most homeowners pay a combined rate between about 1.13% and 1.34% of assessed value, with the city of Alameda near 1.17% and Oakland near 1.34% in the county’s most recent published rates.
When are Alameda County property taxes due?
The county bills once a year and collects in two installments. The first is due November 1 and becomes delinquent after December 10. The second is due February 1 and becomes delinquent after April 10. A 10% penalty applies immediately to any installment paid after its delinquency date.
How do I pay my Alameda County property tax bill online?
Use the Treasurer-Tax Collector’s official property tax portal. Search by parcel number or address, select the installment, then pay by electronic check at no cost or by credit or debit card for a convenience fee of roughly 2.5%. Save the confirmation number after the payment posts.
What is the Homeowners’ Exemption in Alameda County?
The Homeowners’ Exemption reduces the assessed value of your owner-occupied primary residence by $7,000, which saves about $70 a year. File the claim with the Alameda County Assessor by February 15 of the tax year to receive the full benefit.
How do I appeal my Alameda County property tax assessment?
File an Assessment Appeal Application with the Clerk of the Board between July 2 and September 15 for a regular assessment, or within 60 days of the notice for a supplemental or escape assessment. Include comparable sales near the January 1 lien date. Keep paying your taxes on time while the appeal is pending.
What is a supplemental property tax bill in Alameda County?
A supplemental bill covers the difference between the prior owner’s assessed value and your new value, usually your purchase price, after a sale or new construction. It comes separately from your regular bill, often months after closing, and most impound accounts do not cover it. Set cash aside to pay it out of pocket.
What happens if I pay my Alameda County property taxes late?
A 10% penalty is added to the unpaid installment right after the delinquency date. If taxes stay unpaid, additional penalties and fees accrue, and after five years of default, the property can be sold at a tax sale.
Getting the Numbers Right Before You Buy
Property taxes are a permanent line in your monthly payment, and getting them right at the pre-approval stage keeps the surprises out of your first year of ownership. A home in a higher-rate city or a Mello-Roos district changes your payment, and that belongs in the math before you make an offer, not after.
If you are buying or refinancing in Alameda County, we can build your full monthly payment, including the escrow for taxes and insurance, so you see the real number in about 15 minutes. And if a refinance is on the table, especially for debt consolidation, run your full Alameda County tax bill through the new escrow analysis. A higher rate that lowers your total monthly payment can still be the right move.
Ready to talk through your Alameda County home purchase or refinance? Contact JVM Lending today for a free rate quote.
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Sources
Alameda County Auditor-Controller (2024-2025 Tax Rate Book and Tax Rate Search); Alameda County Assessor (assessment appeals, calendar, and exemptions); Alameda County Treasurer-Tax Collector (payment and due dates); California State Board of Equalization (Proposition 13).
*Please Note: The information provided in this blog post is intended for informational and educational purposes only. JVM Lending is not a tax professional or financial advisor. Property tax laws and regulations can be complex and may vary by location and individual circumstances. We strongly recommend consulting with certified tax professionals for personalized advice and guidance on property tax matters. If you’d like a referral to a tax professional or financial advisor, contact us, and we’ll happily refer you to one of the trusted professionals in our network.
