Alameda County Property Tax Guide for Homeowners and Sellers

Last updated November 13, 2026. Reviewed by the Cash Home Buyers CA team. Dates and fees come from the Alameda County Treasurer-Tax Collector; sources are listed at the end.

Alameda County secured property taxes are paid in two installments: the first is late after 5 p.m. on December 10, and the second is late after 5 p.m. on April 10. A late first installment adds a 10 percent penalty, and a late second installment adds 10 percent plus a $10 cost.

Taxes still unpaid after June 30 are declared defaulted and start growing every month. If you sell, taxes owed are paid out of your proceeds at closing.

Alameda County property tax at a glance

First installment	Due November 1, late after 5 p.m. on December 10: 10% penalty
Second installment	Due February 1, late after 5 p.m. on April 10: 10% penalty plus a $10 cost
Weekend or holiday deadline	Payment by 5 p.m. the next business day avoids the penalty
After June 30	Defaulted: delinquent penalties and costs, a 1.5% redemption penalty added on the first of each month, and a redemption fee
Tax sale	The Tax Collector may sell defaulted property not redeemed after 5 years
Pay online	propertytax.alamedacountyca.gov: free eCheck, or a card with a fee
Pay by phone	(510) 272-6800, 24-hour automated system
Office	Treasurer-Tax Collector, 1221 Oak Street, Room 131, Oakland, CA 94612
Returned payment fee	$61.00

When are Alameda County property taxes due?

The first installment is due November 1 and becomes delinquent at 5 p.m. on December 10. The second is due February 1 and becomes delinquent at 5 p.m. on April 10. When either date lands on a weekend or legal holiday, a payment made by 5 p.m. the next business day avoids the penalty.

For the 2026-27 bill, December 10, 2026 is a Thursday, and April 10, 2027 is a Saturday, so the second deadline moves to Monday, April 12, 2027.

• You can pay both installments at once. Send the total due with both installment stubs by December 10.
• If you have not received a bill, contact the Treasurer-Tax Collector. The county’s 2025 notice asked owners without a bill by November 10 to get in touch.
• Online payments are available around the clock, and the county’s phone system runs 24 hours a day.

How do I pay my Alameda County property tax bill?

Start at the county’s property tax website, propertytax.alamedacountyca.gov, to look up a bill by parcel number or address. Payment options are:

• eCheck online: free, available 24 hours a day.
• Credit card: online or by phone, with a convenience fee. Cards are not accepted by mail or at the counter.
• Drop box and mail slot: checks only, never cash. The drop box is at the County Administration Building entrance, and a mail slot is at the Hayward Business License Office, 224 W. Winton Ave., Room 169. Both are open 8:30 a.m. to 5 p.m. on weekdays.
• By mail: send a check to the county’s lock box at P.O. Box 45862, San Francisco, CA 94145-0862.

If an online payment is rejected, the county says the current year’s payment must then be mailed with the $61.00 returned-check fee before the due date, so pay early enough to fix a problem.

What happens if I don’t pay property taxes in Alameda County?

A late installment gets the 10 percent penalty immediately. If taxes remain unpaid after 5 p.m. on June 30, the first year of delinquency is declared defaulted.

From then on you owe the delinquent penalties and costs, a redemption fee, and a 1.5 percent redemption penalty that is added on the first day of each month. That monthly charge is 18 percent a year on the defaulted amount, which is why a small bill can grow quickly.

The Tax Collector may sell defaulted property that is not redeemed after five years. Before that point you can redeem by paying everything owed. Our guide to the tax-defaulted auction process explains how the five-year clock works in a neighboring county, and the same state rules apply in Alameda County. If you are also behind on the mortgage, see California’s foreclosure report.

What is a supplemental tax bill in Alameda County?

A supplemental bill taxes an increase in assessed value caused by a change of ownership or new construction, prorated from the date of the change. It comes in addition to the regular annual bill.

The county also issues escape bills, which tax an increased valuation from a delayed reappraisal or an exemption that was applied by mistake. Questions about either go to the Assessor’s Office at (510) 272-3787.

New owners and heirs who inherit a home are the ones most often surprised by these bills.

Estimate the transfer tax when you sell

Property tax is one cost of selling; transfer tax is another. State law sets the county documentary transfer tax at $0.55 per $500 of value. The calculator below uses that rate. Some cities in Alameda County add their own transfer tax, which this estimate leaves out, so ask your escrow officer for the exact total.

How to sell a house in Alameda County when you owe property taxes

You can sell a house in Alameda County with unpaid property taxes. Taxes are a lien on the home, so the escrow company pays what is owed from your proceeds at closing and the buyer receives the property with the taxes cleared.

1. Get the payoff amount. Look the parcel up on the county’s property tax website or call (510) 272-6800. Defaulted amounts grow on the first of each month, so ask for the figure in the month you expect to close.
2. Expect proration. The current year’s tax is split between you and the buyer by the closing date.
3. Time the closing. Closing before December 10 or April 10 avoids the penalty on that installment.
4. Check your options. Compare a listing, which brings showings, repairs and a buyer’s loan approval, with a cash sale that closes on a date you choose.

We buy houses across the county as they are. See our Alameda County cash home buyer page, our Oakland page and how our Oakland cash-offer process works.

Behind on Alameda County property taxes and thinking about selling? Call (424) 435-2326 or request a cash offer. There is no cost and no obligation.

Alameda County property tax FAQ

When is the Alameda County property tax deadline?

December 10 for the first installment and April 10 for the second, both at 5 p.m. A deadline on a weekend or holiday moves to the next business day.

What is the late penalty on Alameda County property taxes?

10 percent on either installment, plus a $10 cost on the second installment. Taxes unpaid after June 30 also accrue a 1.5 percent monthly redemption penalty.

Can I pay Alameda County property taxes online?

Yes. eCheck is free and cards carry a convenience fee. Online and phone payments are available 24 hours a day.

How long can property taxes go unpaid in Alameda County before the home is sold?

The Tax Collector may sell defaulted property that is not redeemed after five years.

How do I sell a house in Alameda County with delinquent property taxes?

Get the payoff amount from the Tax Collector, give it to escrow, and the taxes are paid from your proceeds at closing. If the amount is close to what the house will sell for, call us before listing so the numbers are clear first.

Sources

• Alameda County Treasurer-Tax Collector: Taxes FAQs
• Alameda County: Secured Property Tax Due 2025-2026 press release
• Sacramento County Clerk-Recorder fee schedule (statutory $0.55 per $500 under Revenue and Taxation Code 11911)

This guide is general information, not tax or legal advice. Dates, fees and rates can change; confirm the amount on your own bill with the Alameda County Treasurer-Tax Collector.