Alameda County property tax.
What you’ll pay, when, and how to pay less.

By Amrit Singh, REALTOR® · The Oberoi Group at Intero Real Estate · Published October 11, 2026 · Rates and dates checked October 11, 2026

Property tax is the biggest bill most homeowners never read closely. Buy a home in Alameda County and you’ll pay somewhere between about 1.1% and 1.35% of the price every year, split into two installments, with an extra bill a few months after closing that catches a lot of people off guard.

Here’s how the bill works, what the rate is in every city this year, when it’s due, and the legal ways to pay less.

How your bill is calculated

Every regular bill comes down to three things:

• Your assessed value. Under Prop 13 it’s set to the price when you buy, then it can rise at most 2% a year, whatever the market does. For the 2026 to 2027 bills the increase was the full 2%. Add a room or an ADU and the addition gets assessed too.
• The tax rate. 1% of the assessed value countywide, plus voter approved bonds for your school district, community college, BART, parks and water. That second part is why rates differ from city to city.
• Fixed charges. Parcel taxes, assessments and Mello-Roos are flat amounts listed separately on the bill. They don’t depend on your home’s value.

If the home is your main home on January 1 and you’ve claimed the homeowners’ exemption, $7,000 comes off the assessed value first.

So a $1,500,000 home in Fremont that you live in works out to $1,500,000 minus $7,000, times 1.1746%: about $17,537 a year, plus whatever fixed charges the parcel carries. That’s two installments of about $8,768.

Estimate your tax

Pick the city, enter the price or your assessed value, and add any fixed charges from the bill.

Property tax rates by city, 2026 to 2027

These are the 2026 to 2027 rates from the Alameda County Auditor-Controller for each city’s main tax rate area. Some cities have more than one tax rate area, so your exact rate is printed on your bill.

*A main home with the $7,000 homeowners’ exemption, before fixed charges. Castro Valley, San Lorenzo and Sunol are unincorporated areas.

Livermore and Sunol sit at the low end. Albany is the highest of the cities. Fremont’s rate barely moved from last year’s 1.1741%.

Why Union City pays more than Fremont

Every rate starts at the same 1%. The difference is the bonds each area’s voters have approved:

Main tax rate area in each city: Fremont 12-013, Union City 15-030, Newark 11-010, Hayward 25-001. School districts: Fremont Unified, New Haven Unified (Union City), Newark Unified and Hayward Unified. Colleges: Ohlone (Fremont and Newark) and Chabot-Las Positas (Union City and Hayward).

Union City’s rate is higher mostly because of school bonds: New Haven Unified’s add 0.1720%, against 0.0912% for Fremont Unified. On a $1,500,000 home the total difference comes to about $1,340 a year. Weigh that against what the same budget buys in each city.

When it’s due

The tax year runs July 1 to June 30, and bills go out in the fall. You can pay both installments at once.

*April 10, 2027 is a Saturday, so the deadline moves to the next business day.

Taxes still unpaid after June 30 go into default, and penalties of 1.5% a month start adding up. If your lender pays from an impound account, it pays the regular bill for you, but check that it did.

The supplemental bill nobody warns you about

When a home sells, the Assessor resets its value to the price as of the closing date. But that year’s regular bill was already set at the seller’s lower value. The supplemental bill makes up the difference:

(Your new value minus the old value) × your tax rate × the share of the tax year that’s left.

Say you buy a Fremont home for $1,500,000 and the seller’s assessed value was $600,000. The difference is $900,000, which at 1.1746% is about $10,571 for a full year. Close in October, and the bill covers November through June, about two thirds of the year: roughly $7,000.

Close between January 1 and May 31 and you’ll get two supplemental bills, one for the rest of that tax year and one for the next, because the next year’s regular bill was also based on the old value.

• It goes to you, not your lender. Plan to pay it yourself, and set the money aside at closing.
• It has its own due dates, printed on the bill.
• It can be a refund. If you paid less than the old assessed value, the supplemental is negative and the county sends you money.

At closing, escrow splits the current year’s regular bill between you and the seller. Your regular bills switch to your value once you’ve owned the home on a January 1. Until then, the supplemental bills cover the difference.

Legal ways to pay less

Claim the homeowners’ exemption

If it’s your main home, the $7,000 exemption saves about $80 to $95 a year depending on the city: about $82 in Fremont, $88 in Union City, $80 in Newark and $84 in Hayward. It’s small, but you file once and it stays on until you move. File by February 15 for the full amount. File between February 16 and December 10 and you get 80% of it. New owners usually get the claim form in the mail after closing; the Assessor’s exemption line is (510) 272-3770.

Ask for a lower value if the market dropped

Prop 13 caps how fast your assessed value can rise. Prop 8 works the other way: if your home’s market value on January 1 was below its assessed value, the Assessor can lower it for that year. That mostly matters if you bought near a peak, and in some East Bay neighborhoods prices have already come down.

Start with an informal review: send the Assessor a letter with your parcel number, the address, your opinion of value and your reasons, with “INFORMAL REVIEW” on the envelope. To protect your formal appeal rights, file with the Assessment Appeals Board between July 2 and September 15. The fee is $50 and you can file online ↗. A supplemental assessment can be appealed within 60 days of the notice. When prices recover, the value can climb back up to the Prop 13 level faster than 2% a year.

Moving at 55 or older? Take your tax base with you

Prop 19 lets homeowners 55 and older carry their assessed value to a new home anywhere in California, up to three times. Run your numbers with my Prop 19 calculator.

Inheriting a home

A parent’s low assessed value can pass to a child who moves in, up to a cap. The Prop 19 calculator covers that case too.

Postpone it if you’re 62 or older

California’s Property Tax Postponement program lets homeowners who are 62 or older, blind or disabled put off the current year’s tax if household income was $57,002 or less in 2025, they have at least 40% equity and they don’t have a reverse mortgage. It’s a loan, not forgiveness: the state pays the tax, charges 5% a year, and is repaid when you sell, move out or refinance. Applications for 2026 to 2027 opened October 1, 2026 and close February 10, 2027, and funding is limited.

Disabled veterans

Veterans rated 100% disabled from their service, or paid at the 100% rate, and some surviving spouses can exempt a large part of their home’s value. The amount changes every year. The Assessor’s office has the claim form.

Fixed charges and Mello-Roos

Look at the second half of your bill. Fixed charges are flat amounts for things like school and city parcel taxes, mosquito and vector control, and park or lighting districts. They don’t go down when your value does, and they don’t move with you under Prop 19. Some school parcel taxes have senior exemptions; call the agency listed on your bill.

Newer neighborhoods can also carry a Mello-Roos special tax that pays off the bonds that built their streets, parks and schools. In Hayward’s Eden Shores, the city’s Community Facilities District No. 1 tax for the 2025 to 2026 tax year was $1,182.32 for a home in Zone A and $853.90 in Zone B. Before you write an offer, ask for the seller’s last tax bill and find out how many years any Mello-Roos tax has left.

Transfer tax when you sell

Separate from property tax, Alameda County charges a documentary transfer tax of $1.10 per $1,000 of the price when a home sells. Some cities add their own:

On a $1,500,000 sale that’s $1,650 in Fremont, Union City or Newark, and $14,400 in Hayward. By local custom the seller pays the county tax and buyer and seller split any city tax, but it’s negotiable. Here’s everything else that comes out of a sale.

Questions people ask

I’m a REALTOR®, not a tax advisor or attorney. This guide and the estimator are general information, not tax or legal advice. Rates, dates and amounts are for the 2026 to 2027 tax year and were checked October 11, 2026. Your bill, the Assessor and the Tax Collector have the final word.