San Mateo County Tax Collector: Pay Property Tax, Search Bills & Get Help
If you need to pay a San Mateo County property-tax bill, find a tax account, check a deadline, mail a payment, understand a delinquency or figure out which county department handles your question, this guide helps you reach the correct official service.
Quick Answer: Who Is the San Mateo County Tax Collector?
The county tax-collection function is handled by the San Mateo County Treasurer-Tax Collector. The office collects secured, unsecured and supplemental property taxes, provides taxpayer assistance, processes payments and administers delinquent-tax and tax-defaulted-property processes.
The current Treasurer/Tax Collector listed by San Mateo County is Sandie Arnott. The main public office is at 555 County Center, 1st Floor, Redwood City, CA 94063.
When Is Your
Next Tax Deadline?
Select your state — see your exact deadline, live countdown, and whether you’re on time or already accruing penalties.
TaxCollectors.org is not the government office. Use the official county system for actual payments, account information and other government transactions.
Property Tax Penalty & Interest Calculator
State-specific penalty rates • Interest accrual • Tax lien deadline • Cost-of-waiting breakdown
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On this page: San Mateo County Tax Collector
How to Pay San Mateo County Property Taxes Online
The safest starting point is the official San Mateo County Tax Collector website. From there, use the county’s property-tax payment system rather than an advertisement or an unrelated third-party payment page.
- Open the official county Tax Collector website. Confirm that the service is for San Mateo County before entering account or payment information.
- Open the property-tax payment system. The county’s payment system can be used to examine parcel information and pay property taxes.
- Verify the tax account. Match the property, bill type, tax year, installment and amount before paying.
- Choose your payment method. E-check is currently listed without a fee. Credit-card and PayPal transactions carry a 2.35% service fee.
- Save the confirmation. Keep the confirmation and transaction details until the payment is reflected in the county record.
Online payments are available around the clock
San Mateo County states that electronic payments can be made 24/7 and are accepted until 11:59 PM Pacific Time on the delinquency date. Do not wait until the final minutes if a payment is important.
Check the account before making a second payment
If an online payment appears delayed or unsuccessful, check your transaction confirmation first. Contact the Tax Collector before submitting another payment when there is a reasonable possibility that the first transaction was accepted.
San Mateo County Property Tax Bill Search
The county’s Tax Payment System is the appropriate starting point for searching and paying property-tax bills. The official county page says taxpayers can examine parcel information and special charges on their bill through the online system.
Secured property tax
This is the regular annual property-tax bill secured by the real property. The standard bill is payable in two installments.
Unsecured property tax
Unsecured taxes follow a different deadline and collection process. Do not apply the secured-property schedule automatically.
Supplemental or escape bill
These bills can arise from specific assessment events and may have different delinquency dates or payment instructions.
Have these details ready
- Property address.
- Tax bill or account information.
- Tax year or fiscal year.
- Installment number when applicable.
- Owner information shown on the bill.
Did not receive your tax bill?
Do not assume that non-receipt eliminates the tax obligation. San Mateo County states that taxpayers can obtain a duplicate bill through the Tax Collector and use the county’s online system to determine the amount due.
San Mateo County Tax Collector Office, Hours & Phone
The main Tax Collector office is located at 555 County Center, 1st Floor, Redwood City, CA 94063. Current county information lists public and phone hours as Monday through Friday, 9:00 AM to 5:00 PM, excluding holidays.
Seasonal satellite offices
San Mateo County has also published seasonal Tax Collector service locations in South San Francisco and Half Moon Bay. Specific dates and hours can vary by collection period, so check the current county announcement or the information included with your tax bill.
Redwood City parking
The county states that meters in the County parking structure allow four hours of parking. Check current county directions before travelling to the office.
San Mateo County Property Tax Payment Fees
The payment method can affect the total amount charged. The current county payment information lists no fee for electronic checks and a percentage-based service fee for card and PayPal transactions.
| Payment method | Current published fee | Important detail |
|---|---|---|
| E-check | No fee | Uses an electronic funds transfer from a checking or savings account. |
| Credit card | 2.35% service fee | The county also lists a $1.95 minimum transaction fee. |
| PayPal | 2.35% online service fee | Review the live county payment page before submitting. |
| PIN debit in person | $2.95 per transaction | Listed by the county as an in-person payment option. |
The county does not keep the card service fee
San Mateo County explains that the credit-card service fee is imposed through the payment/card arrangement and is passed to the customer rather than absorbed by the county.
San Mateo County Property Tax Due Dates
For regular secured property taxes, the annual bill is divided into two installments. These dates should not automatically be applied to supplemental, escape or unsecured bills.
| Date | Event | Published consequence |
|---|---|---|
| July 1 | Beginning of fiscal year | For secured defaulted parcels, redemption and monthly penalties apply under the county’s published rules. |
| August 31 | Unsecured property-tax deadline | 10% penalty and $35 collection fee are added after the deadline. |
| November 1 | First secured installment due | The first installment becomes payable. |
| December 10 | First secured installment deadline | 10% penalty is added after the deadline. |
| February 1 | Second secured installment due | The second installment becomes payable. |
| April 10 | Second secured installment deadline | 10% penalty plus $40 cost is added after the deadline. |
| June 30 | End of fiscal year | Unpaid secured taxes can enter the tax-default process. |
Weekend and holiday rule
San Mateo County states that if a delinquent date falls on a weekend or holiday, the penalty is not imposed until 5:00 PM on the next business day.
Where to Mail San Mateo County Property Tax Payments
San Mateo County uses different mailing instructions depending on the type of bill. Do not automatically send every property-tax payment to the Redwood City office.
| Bill type | Mail payment to |
|---|---|
| Secured annual bills | San Mateo County Tax Collector P.O. Box 45878 San Francisco, CA 94145-0878 |
| Unsecured annual bills | San Mateo County Tax Collector P.O. Box 45901 San Francisco, CA 94145 |
| Supplemental and escape bills | San Mateo County Tax Collector 555 County Center, 1st Floor Redwood City, CA 94063 |
Use the USPS postmark rule carefully
San Mateo County states that a United States Postal Service postmark determines whether a mailed payment was timely. A private Pitney Bowes or other postage-meter date does not replace the USPS postmark for this purpose.
When possible, use the envelope supplied with the tax bill and include the applicable payment coupon. If you have lost the envelope, follow the current county mailing instructions rather than guessing which address to use.
San Mateo County Supplemental Property Taxes
Supplemental property taxes can result from a change in ownership or new construction. The supplemental bill represents tax due on the difference between the old and new assessed values for the applicable period.
Why a supplemental bill appears
- A qualifying change in property ownership.
- New construction or another assessment event.
- A reassessment that changes the taxable value for the applicable period.
Why the deadline can differ
San Mateo County explains that supplemental-tax delinquency dates depend on when the bill was mailed. Use the dates printed on the actual supplemental bill instead of automatically applying the annual secured-tax schedule.
Example of a supplemental schedule
The county’s published information explains that a supplemental bill mailed between July and October can carry December 10 and April 10 delinquency dates. Bills mailed later in the fiscal year can have different dates based on the mailing month.
San Mateo County Delinquent Property Taxes
If a regular secured installment is not paid by its deadline, the county adds the applicable statutory penalty. Continued nonpayment can eventually move the property into tax-default status.
First-installment delinquency
After the December 10 deadline, a 10% penalty is added. If the deadline falls on a weekend or holiday, the county’s next-business-day rule applies.
Second-installment delinquency
After April 10, the county lists a 10% penalty plus a $40 cost. Verify the current account amount through the official county system.
If you are dealing with a prior-year delinquency, do not estimate the payoff from the original bill. Additional charges can accrue after the fiscal year ends, so obtain the current amount directly from the Tax Collector.
San Mateo County Tax Default & Redemption
June 30 is the end of the fiscal year. San Mateo County states that beginning July 1, a $35 redemption fee and a 1.5% monthly penalty are added to secured defaulted parcels.
Tax-default accounts need account-specific information
A normal tax bill does not tell you the current redemption amount for a defaulted parcel. If you are trying to stop a tax-default problem, request the current amount and instructions from the Tax Collector rather than relying on a generic calculator.
The Tax Collector also administers public auctions involving tax-defaulted property. Auction information is separate from ordinary current-year property-tax payment and should be reviewed through the official county tax-sale material.
Can You Pay San Mateo County Property Taxes Monthly?
San Mateo County currently offers a monthly property-tax payment option through Easy Smart Pay. The county’s materials make clear that Easy Smart Pay is a private business and is not controlled by the San Mateo County Treasurer-Tax Collector.
Understand the third-party relationship
If you use the monthly payment program, you are leaving the county’s website and interacting with a private provider. Review the provider’s current terms, security information and payment conditions before enrolling.
This option should not be confused with paying the county directly through its standard property-tax payment system. The regular county system remains the appropriate route when you simply want to make a normal property-tax payment.
San Mateo County Tax Collector vs Assessor vs Controller
Several county departments participate in property taxation. Knowing which office owns the problem can save time and prevent a payment question from being sent to the department responsible for assessed value or tax computation.
Choose the office based on your question
The San Mateo County government describes the Tax Collector as responsible for mailing tax bills and collecting the amount computed by the Controller. The Assessor identifies taxable property, establishes taxable value and applies certain exemptions. The Controller computes the amount of taxes due and apportions and distributes collected property-tax revenue.
Common San Mateo County Property Tax Problems
I did not receive a bill
Use the official tax-payment system or contact the Tax Collector. Do not assume that missing mail removes the obligation to pay.
My payment was returned
Check the payment method and account information, then contact the county if the transaction needs correction. A returned payment can have additional consequences.
My mortgage company pays taxes
Check both the lender’s escrow record and the county account. Confirm whether the installment was actually received before making another payment.
I mailed the payment
Keep proof of mailing and remember that the county uses the USPS postmark for timely mailed-payment determination.
My assessment is wrong
A payment office may not be able to change an assessed value. Start with the Assessor for valuation and related assessment questions.
I have a tax-default notice
Do not calculate the payoff using only the original bill. Contact the Tax Collector for current redemption information.
Official San Mateo County Tax Resources
Property tax and payment
Contact and department routing
San Mateo County Tax Collector FAQs
What is the official San Mateo County Tax Collector website?
The official website is smcgov.org/tax. TaxCollectors.org is an independent guide.
Who is the San Mateo County Treasurer-Tax Collector?
The current Treasurer/Tax Collector listed by the county is Sandie Arnott.
What is the San Mateo County Tax Collector phone number?
The Tax Collector’s customer-assistance number is 866-220-0308.
Where is the San Mateo County Tax Collector office?
The main office is at 555 County Center, 1st Floor, Redwood City, CA 94063.
What are the Tax Collector office hours?
The current public office hours are Monday through Friday, 9 AM to 5 PM, excluding holidays.
When is the first San Mateo County property tax installment due?
The first regular secured-property-tax installment is due November 1. The payment deadline is December 10.
When is the second property tax installment due?
The second regular secured-property-tax installment is due February 1. The payment deadline is April 10.
What happens after December 10?
A 10% penalty is added after the first secured-property-tax installment deadline.
What happens after April 10?
A 10% penalty plus a $40 cost is added after the second secured-property-tax installment deadline.
How much is the San Mateo County credit-card payment fee?
The county currently lists a 2.35% service fee for online credit-card payments and a $1.95 minimum transaction fee.
Can I pay property taxes by e-check?
Yes. The county currently lists electronic-check payments with no fee.
Can I use PayPal to pay San Mateo County property taxes?
Yes. The county currently lists PayPal as an online payment option with a 2.35% service fee.
Can I pay online at night or on weekends?
San Mateo County states that electronic payments can be made 24/7 and are accepted until 11:59 PM Pacific Time on the delinquency date.
Where do I mail secured property tax payments?
For secured annual bills, the county lists San Mateo County Tax Collector, P.O. Box 45878, San Francisco, CA 94145-0878.
Where do I mail unsecured property tax payments?
For unsecured annual bills, the county lists San Mateo County Tax Collector, P.O. Box 45901, San Francisco, CA 94145.
Where do I mail supplemental or escape tax payments?
The county lists 555 County Center, 1st Floor, Redwood City, CA 94063 for other bills including supplemental and escape bills.
Does a private postage-meter date count as the tax payment postmark?
No. The county states that the United States Postal Service postmark is used to determine timely mailed payment rather than a private postage-meter date.
What happens after June 30 to unpaid secured taxes?
Beginning July 1, the county states that a $35 redemption fee and 1.5% monthly penalty are added to secured defaulted parcels.
Is the Tax Collector the same as the San Mateo County Assessor?
No. The Tax Collector handles collection and payment matters. The Assessor handles taxable-property identification, assessed value and certain exemptions and exclusions.
Who handles San Mateo County property tax rates and calculations?
The County Controller handles computation of property taxes and the apportionment and distribution of collected property-tax revenue.
Is TaxCollectors.org the official San Mateo County Tax Collector?
No. TaxCollectors.org is an independent informational website. Actual government payments and account services should be completed through official San Mateo County systems.
Before You Pay San Mateo County Property Taxes
Start with the official Tax Collector website, identify the correct bill type, verify the tax year and installment, check the current payment fee and save your confirmation.
- Use the official county payment system for actual payments.
- Remember December 10 and April 10 for regular secured-tax deadlines.
- Do not apply secured-tax dates to supplemental or unsecured bills without checking the applicable bill.
- Use the correct mailing address for the bill type.
- Remember that the county uses the USPS postmark for mailed-payment timing.
- Contact the Assessor for assessed-value issues and the Controller for tax-computation questions.
- Use account-specific county information for delinquent or tax-defaulted property.