Mariposa County Property Tax Guide for Homeowners and Sellers

Last updated November 13, 2026. Reviewed by the Cash Home Buyers CA team. Figures come from Mariposa County’s published tax notices and Important Dates page; sources are listed at the end. Always confirm amounts on your own bill.

Mariposa County sends one secured property tax bill a year, payable in two installments: the first is due November 1 and late after 5:00 p.m. on December 10, and the second is due February 1 and late after 5:00 p.m. on April 10. A late first installment adds a 10 percent penalty.

A late second installment adds a 10 percent penalty plus a $20 cost. If you sell a house with taxes owing, the escrow company pays them from your proceeds at closing.

Mariposa County property tax at a glance

First installment	Due November 1; late after 5:00 p.m. on December 10 (2025 bill: December 10, 2025)
Second installment	Due February 1; late after 5:00 p.m. on April 10 (2025-26 bill: April 10, 2026)
Late penalty, first installment	10% of the installment
Late penalty, second installment	10% plus a $20.00 cost
After June 30	Unpaid taxes go on the delinquent tax roll: a $15 fee, then 1.5% a month
Pay both at once	Allowed, but both must be paid by the first installment’s deadline to avoid late fees
By mail	PO Box 247, Mariposa, CA 95338; postmarked by the delinquent date
In person	4982 10th Street, Mariposa, 8:00 a.m. to 5:00 p.m. Monday to Friday, holidays excepted
Phone	209-966-2621

When are Mariposa County property taxes due?

The county’s notice for the 2025-26 tax year lists the first installment as due November 1, 2025 and delinquent if not paid by 5:00 p.m. on December 10, 2025. The second installment is due February 1, 2026 and delinquent after 5:00 p.m. on April 10, 2026. The same November, December, February and April pattern repeats every year.

Supplemental bills, which follow a change of ownership or new construction, work differently. The county says they are due on the date the bill is mailed, so read the delinquent date printed on the bill itself. Unsecured bills for business property have their own schedule, with the county’s Important Dates page listing August 31 as the deadline.

• Mailed payments must be postmarked by the delinquent date, and the county warns owners to mail early because postmark practices have changed.
• You may pay both installments together, but both have to be paid by the first deadline to avoid late fees.
• Delinquent notices for unpaid current-year taxes are mailed in May.

How do I pay my Mariposa County property tax bill?

You can pay online through the county website at mariposacounty.org, by mail, or in person. Mail goes to PO Box 247, Mariposa, CA 95338. The Tax Collector’s counter is at 4982 10th Street in Mariposa and is open 8:00 to 5:00, Monday through Friday, except holidays. For questions about a bill, call 209-966-2621.

If your lender pays taxes from an impound account, you should still check that the payment posted before the deadline, because the owner is the one charged when a payment is missed.

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

Each missed installment carries the penalties above. If taxes are still unpaid on June 30, the county’s Important Dates page says the account moves to the delinquent tax roll around July 1, where a $15 redemption fee applies and a 1.5 percent penalty is added each month to the unpaid amount. At 1.5 percent a month, a $3,000 unpaid balance grows by $45 every month on top of the earlier 10 percent penalties.

The county’s pages I reviewed do not describe the length of the tax-default period or the auction process, so ask the Tax Collector for the timeline on your parcel. Acting early is cheaper than waiting: the penalties are charged on schedule whether or not you received a reminder.

If you are also behind on the mortgage, read how to sell a house in foreclosure.

What is a supplemental tax bill in Mariposa County?

A supplemental bill is an extra bill issued when a property is reassessed after a sale, inheritance or new construction. The county states that supplemental bills are due on the date mailed, with the delinquent date shown on the bill.

They are separate from the annual bill, so a new owner should not assume the regular bill covers them. Heirs who keep or sell a parent’s house should read our page on how to sell an inherited property.

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

You can sell a house in Mariposa County with unpaid property taxes. Taxes are a lien on the property, so escrow pays the amount owed out of your proceeds and the buyer takes the property with the taxes current.

1. Get the amount due. Call the Tax Collector at 209-966-2621 or check your bill. Ask for the figure in the month you expect to close, since interest adds up monthly after June 30.
2. Expect proration. The current year’s tax is split between you and the buyer by closing date.
3. Plan for transfer tax. California law sets the county documentary transfer tax at $0.55 per $500 of the sale price; use the calculator below for an estimate. Check with escrow for any city tax.
4. Watch the calendar. Closing before December 10 or April 10 avoids the penalty on that installment.

A cash sale helps when time is the problem, because there is no loan approval to wait for. See our Mariposa County cash home buyer page for how it works.

Estimate your transfer tax when you sell

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

Mariposa County property tax FAQ

When is the second installment late in Mariposa County?

After 5:00 p.m. on April 10. A 10 percent penalty and a $20 cost are added after that deadline.

Where do I mail my Mariposa County property tax payment?

PO Box 247, Mariposa, CA 95338. It must be postmarked by the delinquent date, and the county recommends mailing early.

What fees apply when taxes go delinquent after June 30?

A $15 redemption fee applies when the account moves to the delinquent roll, and a 1.5 percent penalty is added each month to the unpaid amount.

Who pays property tax in the year a Mariposa County house is sold?

Both sides, each for their share of the year. Escrow prorates the bill to the closing date, and the buyer may later receive a supplemental bill.

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

Get the payoff from the Tax Collector, give it to escrow, and the delinquent taxes are paid from your proceeds at closing.

Sources

• Mariposa County: Notice of 2025 Current Property Taxes Due
• Mariposa County: Important Dates
• Sacramento County Clerk-Recorder: Documentary Transfer Tax (state rate under Revenue and Taxation Code 11911)

This guide is general information, not tax or legal advice. Rates, fees and dates can change; confirm the amount on your own bill with the Mariposa County Tax Collector.