Every L.A. County Property Tax Deadline That Costs Money, in the Order They Arrive

Twelve dates run the Los Angeles County property tax year. One of them is three weeks away, two of them move in 2027, and one late fee is published two different ways on two county pages. Here is the whole calendar, with the penalty attached to each miss.

Nobody misses a property tax deadline on purpose. They miss it because the bill arrives in October for a payment the county wants in November, because the second half is due in February and not penalized until April, because the window to argue about the value closed four months before the bill that reflects it showed up, or because the envelope went to the address they moved out of in 2019. The dates are all published. They are published across four different government websites, in four different vocabularies, and nowhere in one list.

So here is the list. We read the Treasurer and Tax Collector's secured and unsecured pages, the Board of Supervisors' assessment appeals rules, the Assessor's own decline-in-value guide and the seven sections of state law that set the dates, and put the whole cycle in the order a property owner actually meets it. Every penalty below is the one the county or the code names, and every date is the one it names it for.

First, the shape of the year

Two things explain most of the confusion. The first: the county's tax year is not the calendar year. The fiscal tax year runs July 1 through June 30, which is why a bill mailed in October covers a year that started in July, and why paying in full in December still leaves you six months from the end of the year the payment belongs to.

The second: everything about that year was decided on a single morning. Under Revenue and Taxation Code section 2192, "all tax liens attach annually as of 12:01 a.m. on the first day of January preceding the fiscal year for which the taxes are levied." That is the lien date, and it is the reason the answer to almost every question below is a January 1 fact: who owned it on January 1, what it was worth on January 1, whether you lived there on January 1.

There are also two separate tax systems with two separate calendars. Secured taxes are the ones on real property — the house, the lot, the building. Unsecured taxes are the ones on everything else the county assesses: the Treasurer and Tax Collector's own definition covers boats, jet skis, aircraft, business fixtures, business furniture and business machinery. They do not share a due date, and the nearest deadline on the whole calendar belongs to the second one.

August 31, 5 p.m. — boats, planes and business equipment

Unsecured property tax, delinquent after 5 p.m. on August 31. The bills went out between March 1 and June 30; if one never arrived, the county's instruction is that you should have gone looking for it by July 15, when a copy becomes viewable online. Under Revenue and Taxation Code section 2922, the tax is due on receipt and delinquent after 5 p.m. Pacific time on August 31. This year that is a Monday, so the weekend-and-holiday extension the county applies does not help anyone: August 31, 2026 is the deadline itself.

Note the two different clocks in the same paragraph of the county's page. A mailed payment has to be received or postmarked by August 31. An online payment is accepted until 11:59 p.m. on the delinquency date — nearly seven extra hours, for the same money, at no fee if you pay from a checking account.

This is also the deadline with the most aggressive collection tail. Beyond the penalty, the Treasurer and Tax Collector lists liens, summary judgments, legal action, seizure and sale of personal property, interception of Franchise Tax Board refunds, and a hold on Department of Motor Vehicles registration for boats and jet skis. The boat is the collateral for the tax on the boat.

The same late fee, published two ways

We compared the county's two pages on that penalty, and they do not agree. The unsecured property tax page says a late payment draws a 10 percent penalty plus a $12.00 Notice of Enforcement cost, and that "starting the first day of the third month after the delinquency date" the county adds a $93.00 Notice of Lien cost and 1.5 percent per month until the tax is paid.

The Treasurer and Tax Collector's dedicated penalties page, for the same tax and the same August 31 date, says a 10 percent penalty plus a $20.00 Notice of Enforcement collection cost — and that "starting the first day of the second month after the delinquency date" the county adds a $29.00 Notice of Lien cost and the same 1.5 percent per month.

You're wondering which one is right. On the dollar amounts we can't tell you from the outside, and that is the honest answer: both pages were live on the county's own site this morning, neither carries a revision date, and the difference is $8 in one direction and $64 in the other. On the timing, the statute settles it — section 2922 attaches the additional 1.5 percent per month after two months, which matches the penalties page's "first day of the second month" and not the unsecured page's third. The number that governs your payment is the one printed on your bill. And the practical reading is simpler than the discrepancy, because the two pages agree on the part that costs real money: 10 percent, which is $200 on a $2,000 bill, before anyone argues about a notice fee.

July 2 to November 30 — the two doors for arguing about your value

One window, two entirely different procedures, and most people only know about the expensive one.

Door one: the decline-in-value review, filed with the Assessor. If your property's market value on January 1 was lower than the assessed value on the roll, the Assessor's own guide says you file form RP-87, the Decline-in-Value Review Application, between July 2 and November 30, and that an application is valid if it is postmarked by November 30. This is Proposition 8 relief — the constitutional amendment California voters passed in 1978, which the Assessor's guide describes as allowing a temporary reduction in assessed value when a property's market value falls below it. The form asks you to name two comparable sales that closed as near to January 1 as possible, and no later than March 31. The Assessor's brochure describes the form, the window and the process, and names no filing fee.

Door two: the formal assessment appeal, filed with the Board of Supervisors. Same window — the Assessment Appeals Board's filing dates are July 2 to November 30 for all real and personal property assessments — but a different body hears it, in a quasi-judicial hearing, and it costs $46 to file. The board's page states the fee is non-refundable and has applied to every application since October 1, 2021. If paying it would cause undue financial hardship, a waiver form exists and must be filed with the application.

November 30, 2026 falls on a Monday, so neither door gets a weekend extension this year. And if you want written findings of fact from your appeal hearing — the document you would need to take the decision any further — the board's published fee for that is a minimum of $492.00 per parcel and issue, which is ten times the cost of filing the appeal itself.

One warning the Assessor's guide makes plainly, and almost nobody hears until it happens: a decline-in-value reduction is temporary. It lasts at least one year, and the base value it suspends keeps rising underneath it. When the market recovers, the assessed value snaps back to that trended base value — which means a bill can rise by far more than 2 percent in a single year without anyone breaking Proposition 13. The Assessor's office made the same point in its announcement this summer, telling property owners in a news release reported by The Signal that "as market values recover, assessed values may increase accordingly."

October and November 1 — the bill arrives, or it doesn't

October: annual secured bills are mailed. The Treasurer and Tax Collector mails them throughout October to every owner on the secured roll, and no later than November 1 under state law. If you have an impound account with a lender, the bill goes to the lender and you get an information-only statement.

If it never comes, the clock runs anyway. This is the single most expensive misunderstanding in the system, and the law is one sentence long. Revenue and Taxation Code section 2610.5: "Failure to receive a tax bill shall not relieve the lien of taxes, nor shall it prevent the imposition of penalties imposed by this code." The same section carries two real reliefs, though, and they are worth knowing before you argue: penalties are canceled if the delinquency resulted from the tax collector's failure to mail the bill to the address on file, and where a bill is late, amended or corrected, penalties are canceled if you pay within 30 days of its mailing. Both turn on the address the Assessor has for you, which is the one you change with the Assessor, not the Tax Collector.

December 10 — two deadlines on one day

First installment, delinquent after the close of business on December 10. It was due November 1; the ten weeks between those two dates are the grace period, and the penalty is what waits at the end of it — a flat 10 percent of the installment. December 10, 2026 is a Thursday. Partial payments are accepted and do reduce what the penalty is calculated against, which is the county's own advice for anyone who cannot pay the whole half.

The last day a late homeowners' exemption is worth anything. If you missed the February deadline below, Revenue and Taxation Code section 275 allows a claim filed on or before December 10 at "the lesser of five thousand six hundred dollars ($5,600) or 80 percent" of the exemption. File after December 10 and the current year is simply gone. Read the number carefully: the exemption removes assessed value, not tax — $7,000 off what the property is assessed at, not $7,000 off the bill.

February 1 and April 10 — the half everyone forgets

Second installment, due February 1, delinquent after April 10. The penalty is 10 percent plus a $10.00 cost for giving notice — the ten dollars only ever attaches to the second installment, which is why the county's own worked example shows $550 owed on a late first half and $560 on an identical late second half.

In 2027 the date is not April 10. April 10, 2027 falls on a Saturday, and the county's rule is that when a delinquency date lands on a Saturday or Sunday it extends to the close of business on the next business day. That makes the real 2027 deadline Monday, April 12. It is two free days, and it is also the kind of thing worth confirming on your own bill rather than taking from anyone's calendar, including ours.

February 15 — the exemption, on a day the counters are closed

Homeowners' exemption, full amount, by 5 p.m. on February 15. The state Board of Equalization describes it as a $7,000 reduction in the taxable value of a qualifying owner-occupied home, claimed no later than February 15 for the full exemption. It is claimed once, not annually, and it turns on the January 1 lien date: the home has to have been your principal residence then.

You're wondering about 2027, and you are right to. February 15, 2027 is the third Monday in February, which is Presidents' Day, a Los Angeles County holiday — county offices are closed on the deadline. File it online, or file it the week before. That is the entire fix, and it costs nothing to apply it early.

April 1 and May 7 — the filing with the biggest penalty in the system

Business Property Statement, due April 1, penalized after May 7. If you run a business with equipment, fixtures or furniture, this is the form that reports it. Revenue and Taxation Code section 441 requires it to be filed with the assessor "between the lien date and 5 p.m. on April 1," and states that the late penalty "applies for property statements not filed by May 7." If May 7 falls on a weekend or holiday, a statement postmarked the next business day counts as timely.

The penalty is the one number on this page that is not a flat fee or a tenth of a bill. Under Revenue and Taxation Code section 463, failing to file on time adds "10 percent of the assessed value of the unreported taxable tangible property" to the assessment itself — not 10 percent of the tax, 10 percent of the value, added to the roll and then taxed. On $200,000 of unreported equipment that is $20,000 of extra assessed value, permanently on that year's roll.

June 30 — the cliff

Pay the whole year by June 30, or the taxes default on July 1. The county's language is exact: if the total for the current tax year is not received or postmarked by June 30, unpaid taxes become defaulted the next day, a $15.00 redemption fee is charged, and defaulted taxes are subject to additional penalties of 1.5 percent of the base tax per month. That is 18 percent a year, compounding onto a bill that has already taken two 10 percent hits.

The distinction that matters here: December 10 and April 10 are penalty dates, and June 30 is a status change. After it, you are not a taxpayer who is late; you are a taxpayer whose parcel is on the defaulted roll, and getting off it is a different transaction with its own paperwork.

The deadlines that are not on any calendar

Supplemental bills: due dates you cannot look up in advance. When you buy a property or finish new construction, the Assessor reassesses it and a supplemental bill follows for the difference — on its own schedule, set by Revenue and Taxation Code section 75.52. If the bill is mailed between July and October, it follows the normal dates: first installment delinquent at 5 p.m. on December 10, second on April 10. If it is mailed in any other month, the first installment is delinquent "at 5 p.m. on the last day of the month following the month in which the bill is mailed," and the second four calendar months after that. A bill mailed in January is therefore delinquent at the end of February. New owners are the people this catches, and it catches them because they are waiting for October.

Sixty days, from a date printed on a notice. Appeals of supplemental, escape and roll-change assessments are not tied to the November 30 window at all. The Assessment Appeals Board's filing dates are within 60 days of the mailing date printed on the notice or tax bill, or the postmark date, whichever is later. Keep the envelope.

Six months, after a disaster reassessment. For misfortune and calamity reassessments — the process that follows a fire, a flood or a landslide — the appeal window is six months after the mailing date of the proposed reassessment notice, per the same board. It is the one deadline on this page most likely to arrive while the property owner is living somewhere else, which is exactly why it is worth writing down before it applies to you.

Three habits that are cheaper than any of the above

Pay online, not by mail, on the last day. The county's penalties page is unusually specific about which postage the U.S. Postal Service actually postmarks: standard stamps yes; metered mail, pre-canceled stamps bought through a private vendor such as stamps.com, Automated Postal Center stamps and permit-imprint mail — the category that includes pre-sorted mail used by online bill-pay services — no. If the USPS does not postmark it, the county imposes the penalty on the date it arrives, and your bank's bill-pay is in the second list.

Change your address with the Assessor, not the Tax Collector. The Treasurer and Tax Collector's page says it plainly: it will keep mailing to the address on file until you update it with the Office of the Assessor. This is the mechanism behind most missed bills, and section 2610.5 above is what happens next.

Put four dates in the phone, not one. December 10 and April 10 for the house, August 31 for anything that floats or flies or sits in a shop, and November 30 for the year's one chance to argue about the number all of the others are calculated from. The rest of the calendar is consequences.

Every date, fee and penalty on this page was checked against the source linked beside it on August 11, 2026. Dates that fall on weekends and county holidays move, and the amount that governs your payment is the one printed on your own bill. This page will be re-verified and updated in place each year.