Marin County’s Tax Collector has mailed 91,194 secured property tax bills for the 2026-27 year, adding up to about $1.6 billion. The first installment says November 1 on the bill, but the penalty does not start until after 5 p.m. on Thursday, December 10. The county’s total tax roll is up 3.62% from a year ago.
For most owners that is five extra weeks. The second installment works the same way: the bill says February 1, and the penalty date is Monday, April 12, 2027. The usual April 10 deadline falls on a Saturday, so it moves to the next business day.
What happens after December 10
The Tax Collector’s September 24 release says the first installment is due November 1 and “must be paid by 5 PM Thursday, December 10, to avoid a late penalty.” Owners can pay in two installments or all at once. Online payments are accepted until 11:59 p.m. that day.
Miss the date and the cost is fixed in advance. The county’s payments page lists a 10% penalty on a late first installment. A late second installment draws another 10% plus a $20 administrative cost. On an $8,000 first installment, the first penalty alone would be $800.
Taxes still unpaid at 5 p.m. on June 30 put the property into tax-defaulted status, and the page says additional penalties and costs pile up from there. A returned check adds a $40 fee on top.
Many owners are asking whether the bill can be lowered or postponed before December 10. The State Controller’s Property Tax Postponement Program lets seniors, blind and disabled homeowners defer current-year taxes on a principal residence if they have at least 40% equity. The county says applications for 2026-27 run October 1 through February 10, 2027.
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A redesigned bill and a big number
The bills have a new layout and font this year, with accessibility changes and a QR code that points to the Tax Collector’s website. A guide to reading the new layout is posted there. Anyone who is used to finding the due date in the same spot should look again.
The $1.6 billion covers more than the basic property tax. The county says it includes voter-approved debt, parcel taxes and special assessments. Divided across 91,194 bills, that is roughly $17,500 a bill on average, though the real range runs far wider, and the 3.62% rise describes the whole roll rather than any one owner’s bill.
Paying without a fee
E-check payments cost nothing, and payers get immediate confirmation that the payment went through. Marin County Director of Finance Mina Martinovich said the online portal gives owners a quick, secure way to view bills and pay. Owners need their assessor parcel number to use it.
Cards cost more. The payments page lists a 2.35% service fee, with a $1.49 minimum, charged by a third-party processor, and the county’s release says the county receives none of it. On an $8,000 installment that fee comes to $188. Phone payments go through 1-800-985-7277, with the bill number ready.
Mail needs care. The Postal Service may postmark an envelope when it reaches a processing center, not when it goes in the box, so anyone mailing near the deadline can ask for a manual postmark at a post office counter. Checks go to the Marin County Tax Collector, PO Box 4220, San Rafael, CA 94913-4220, and the office does not recommend paying through a bank’s bill-pay service.
No bill in the mailbox, or a lender that pays
Owners who have not received a bill by mid-October, especially recent buyers, should contact the Tax Collector’s Office at 415-473-6133, the release says. Bills can also be viewed and printed online. A missing bill does not excuse a late payment.
Homeowners whose lender pays taxes from an impound account, a fund the lender collects with the mortgage, should still look at the bill. The payments page says it should be marked that a copy went to a paying agent. If it is not, the owner should call the lender, because the bill must still be paid in full by the due date.
The office is in Suite 202 at the Marin County Civic Center, 3501 Civic Center Drive in San Rafael, open weekdays from 9 a.m. to 4:30 p.m. Questions about assessed value go to the County Assessor at 415-473-7215.
Relief that exists before the penalty date
Marin’s exemptions page lists the Homeowners’ Exemption and the Veterans’ Exemption, both handled through the County Assessor. The page gives no dollar amounts or filing deadlines for either, so the Assessor’s office is where to ask.
Many school and special districts also offer parcel tax exemptions to qualified seniors, the same page says. An owner over 65 living in the home may be eligible, but each district sets its own rules and deadlines. Application forms are posted for agencies including Belvedere, Corte Madera, Mill Valley, Novato, Ross Valley, San Anselmo, San Rafael and Sausalito.
One limit applies to everyone. The county says California law does not allow exemptions from voter-approved school bond taxes, so those lines stay on the bill.
The state postponement program works differently from an exemption, because it defers the current year’s taxes instead of cancelling them. The State Controller’s office takes questions at 1-800-952-5661. Homeowners weighing it against paying on December 10 have until February 10, 2027 to decide, and each has the same question to settle first: whether they meet the age or disability test, the equity rule and the program’s income limit.
Paying Marin’s first installment before December 10?
A Marin owner who files the wrong form, mails a check without a manual postmark or assumes an exemption covers a bond line can end up with a 10% penalty on an installment that runs to thousands of dollars. The relief programs each have their own dates and rules.
The Senior Property Tax & Home-Cost Relief Kit lays out the 5 kinds of property-tax relief and the circuit-breaker credit that includes renters, so a homeowner can see which kind fits their own bill. It also includes an application log and renewal calendar for tracking each deadline.
Get the relief kit and application log for your Marin tax bill →
More Financial Reading
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This article was produced with the assistance of AI and reviewed by the editorial team.
David M. Keller is a finance writer based in Columbus, Ohio, covering personal finance and consumer-focused economic topics. He earned his degree in journalism from Ohio University and began his career reporting on local business and economic trends for a regional media outlet. Since then, he has contributed to a variety of online publications, focusing on clear, practical coverage of topics such as cost of living, debt, and everyday financial decision-making.
