San Mateo County Property Tax Guide: Pay, Search, Due Dates & Exemptions
San Mateo County property taxes are easier to manage when you verify the parcel before you pay. A missing bill, wrong Assessor’s Parcel Number, supplemental bill after a home purchase, escrow payment, late postmark, or exemption issue can change your next step. This guide explains the practical process first, so you understand what to check before using the official Tax Collector or Assessor tools for payment, lookup, forms, refunds, or appeals.
Quick Answer
To handle San Mateo County property tax safely, search the property by Assessor’s Parcel Number or address, confirm the parcel, check the current secured tax bill, verify the installment and due date, review payment status, then use the official Tax Collector payment system for final payment. If you recently bought a property, also watch for supplemental bills because they are separate from the annual secured bill.
Best order: find the property first, read the bill second, check payment status third, then pay. This prevents wrong-parcel payments, missed coupons, duplicate escrow payments, and late penalties.
Before You Pay: 7 Checks That Prevent Most Problems
Most San Mateo County property tax mistakes happen before the payment screen. Use this checklist before entering bank or card details.
San Mateo County Property Tax Help by Situation
Choose the situation that matches your problem. Each path below explains what to check and where to take official action.
| Your Situation | What to Check First | Best Next Step |
|---|---|---|
| I need to find my property tax bill | Search by address or parcel number and confirm the property. | Follow the bill lookup guide |
| I want to pay online | Check APN, installment, amount due, due date, payment status, and fee. | Use the safe payment steps |
| I did not receive a bill | Annual secured bills are mailed by November 1, but you can check the amount online or request a duplicate bill. | Get bill help |
| I just bought a home | Check annual secured bill, supplemental bill risk, escrow documents, and mailing address. | Read new-owner checklist |
| My bill looks too high | Review assessed value, tax rate, special charges, exemptions, and possible supplemental assessments. | Review bill-change causes |
| I may qualify for an exemption | Check Homeowners’ Exemption, Disabled Veterans’ Exemption, and school parcel-tax exemptions if relevant. | Review exemptions |
How to Find a San Mateo County Property Tax Bill
If your bill has not arrived, do not wait for mail near a deadline. San Mateo County Tax Collector resources let you view or pay property taxes online. The Assessor also points users to the Treasurer-Tax Collector’s secured property tax search, where you can look up property tax by address or parcel number.
- Open the official San Mateo County Tax Collector page or secured property tax lookup.
- Search by Assessor’s Parcel Number if you have it.
- Use property address search if the parcel number is not available.
- Confirm the property address, tax year, and installment before relying on the amount.
- Open the bill/payment details and save a copy of the result for your records.
- Open the Assessor’s Property Tax Look-up page.
- Use the link to the secured property tax search.
- Search by address or parcel number.
- Review whether the result is for secured property taxes, not unsecured or supplemental only.
If you did not receive a bill: the Tax Collector says secured bills are mailed by November 1, but you can determine the amount due through the online property system or request a duplicate bill by calling 866-220-0308 or visiting the office.
Search by Parcel Number, Address, or Owner Information
The strongest search method is the Assessor’s Parcel Number because it points to a specific parcel. Address search is useful when the parcel number is missing. Owner-name information can help with research, but it is not the safest payment identifier because names can change after sale, trust ownership, probate, company ownership, or mailing updates.
| Search Method | Best Use | Risk to Avoid |
|---|---|---|
| Parcel number / APN | Best for bills, escrow papers, closing documents, assessment notices, and direct property lookup. | Typing the wrong parcel number or using a parcel from a neighboring property. |
| Property address | Best when you do not have the parcel number. | Selecting the wrong unit, old address, similar street name, or nearby parcel. |
| Owner-related information | Helpful for research or deed-record questions. | Paying based only on a name match without confirming the parcel. |
| Recorded document search | Useful for deed, grantor/grantee, and recorded document research. | Confusing recorded ownership documents with current tax balance. |
- Use recorded document search only when you need deed or grantor/grantee information.
- Confirm the property identity separately before making a tax payment.
- For tax amount due, use the Tax Collector’s property tax system instead.
How to Pay San Mateo County Property Tax
San Mateo County offers online property tax payment through the Tax Collector system. You can pay by e-check or credit card. E-check has no charge; credit card payments are processed by the payment service and include a 2.35% service fee that the Treasurer-Tax Collector does not retain.
- Open the official View/Pay Property Taxes system from San Mateo County Tax Collector.
- Search the property by parcel number or address.
- Confirm the tax year, installment, amount due, and payment status.
- Choose e-check if you want the no-charge electronic check route.
- Choose card only after reviewing the 2.35% service fee.
- Submit payment and save the confirmation or email receipt.
| Payment Method | What to Know | Practical Steps | Official Link |
|---|---|---|---|
| E-check | The official payment-system page says there is no charge for electronic check payments. | Search bill → choose installment → enter bank info → review amount → save confirmation. | Payment system guide |
| Credit card | Credit card payments have a 2.35% service fee through the payment service. | Review service fee → confirm amount → pay → save receipt. | Payment system guide |
| Pay by phone | The secured tax page says card payments can be made by calling 866-220-0308. | Have parcel number and bill details ready before calling. | Secured tax FAQ |
| Mail payments should use the correct coupon and a valid USPS postmark by the delinquent date. | Include coupon → mail early → get proof if close to deadline. | Mail payment rules | |
| In person | The main Tax Collector office is at 555 County Center, Floor 1, Redwood City, CA 94063. | Bring bill, APN, ID if needed, and payment proof. | Office location |
Do not double pay: if your mortgage company usually pays from escrow, check the online payment status before paying yourself. Escrow collection and county payment posting are different events.
Mail Payment Rules, Postmarks, and Coupons
Mail can work, but it has a stricter timing risk. San Mateo County states that the envelope must have a United States Postal Service postmark on or before the tax delinquent date to avoid penalties. A private postage meter date is not the same as a USPS postmark.
- Use the envelope supplied with your tax bill when available.
- Include the proper installment coupon with your check.
- Make sure the correct parcel number appears with the payment.
- If mailing near a deadline, go to the post office counter and request a USPS postmark or proof of mailing.
- Keep a copy of the check, coupon, and mailing proof.
Mailing address shown by the Tax Collector: San Mateo County Tax Collector, PO Box 45878, San Francisco, CA 94145-0878. Make tax checks payable as instructed by the Tax Collector page.
San Mateo County Property Tax Due Dates
San Mateo County secured property tax bills cover the fiscal year from July 1 through June 30 and are paid in two installments. The annual secured tax bill is mailed by November 1.
| Bill / Installment | Due Date | Delinquent Date and Penalty | What to Do |
|---|---|---|---|
| Annual secured tax bill mailed | Bills are mailed by November 1. | Not a payment deadline by itself. | Check online if the paper bill does not arrive. |
| First installment | Due and payable November 1. | Delinquent after 5:00 p.m. December 10; 10% penalty is added. | Pay before the cutoff and keep confirmation. |
| Second installment | Due and payable February 1. | Delinquent after 5:00 p.m. April 10; 10% penalty plus $40 cost is imposed. | Do not wait for escrow; confirm payment posted. |
| Delinquent secured parcels | July 1 starts the next fiscal year. | A redemption fee and monthly redemption penalty may apply to delinquent parcels. | Contact the Tax Collector if prior-year taxes remain unpaid. |
| If due date falls on weekend or holiday | Next business day rule may apply. | Penalty is not imposed until 5:00 p.m. on the next business day. | Still pay early to avoid processing problems. |
- Open the official secured property tax information page.
- Confirm whether you are paying the first or second installment.
- Check the delinquent date and penalty rule.
- If paying online, submit before the official electronic cutoff.
- If mailing, make sure the USPS postmark is on or before the delinquent date.
Why Did My San Mateo County Property Tax Bill Change?
A bill can change because of assessed value, the 1% base tax, voter-approved indebtedness, special charges, supplemental assessments, exemptions, ownership changes, new construction, or delinquent penalties. The Tax Collector explains that tax amounts are based on the January 1 value established by the Assessor, multiplied by the tax rate, usually 1% plus voter-approved indebtedness, with special charges added by local districts and cities.
| Possible Cause | Where to Check | What It Means | Next Step |
|---|---|---|---|
| Assessed value changed | Assessor records and assessment notices. | The taxable value may have changed due to ownership change, new construction, or assessment updates. | Contact the Assessor or review appeal options if the value seems wrong. |
| Special charges added | Tax bill special charges section. | Local districts and cities may add sewer or other special assessments to the bill. | Contact the district listed for charge-specific questions. |
| Supplemental bill issued | Supplemental tax bill and purchase/construction date. | The Assessor reassessed the property after ownership change or new construction. | Read the supplemental tax section before assuming it is a duplicate bill. |
| Exemption missing | Assessor exemption records and bill lines. | A Homeowners’ or Disabled Veterans’ Exemption may not be applied. | Review exemption rules and file if eligible. |
| Late payment penalty | Tax Collector payment status and delinquency date. | Penalty and costs can apply after delinquency deadlines. | Review penalty appeal only if your situation fits official legal criteria. |
Assessor vs Controller vs Tax Collector: Who Handles What?
San Mateo County’s property tax process is split between three main offices. The Assessor determines property value, the Controller determines the amount of taxes to be collected and distributes revenue, and the Tax Collector/Treasurer bills and collects the tax.
| Your Need | Start Here | Why | Official Link |
|---|---|---|---|
| Pay tax or check payment status | Tax Collector / Treasurer. | This office bills and collects taxes, handles payment options, and provides payment help. | Tax Collector |
| Find value or exemption information | Assessor. | This office handles assessed value and many exemption programs. | Assessor |
| Understand tax rate publications | Controller. | The Controller provides property tax overview and tax-rate publications. | Property Tax Rate Book |
| Appeal assessed value | Assessment Appeals Board. | Appeals are separate from paying the tax bill. | Assessment Appeals Board |
| Refund explanation | Controller or Tax Collector depending on issue. | The Assessor says refund inquiries may require the Controller with property details. | Bills and refunds help |
San Mateo County Property Tax Exemptions
Exemptions can reduce taxable assessed value, but they do not all work the same way. Review the Homeowners’ Exemption first if you own and occupy the home as your principal residence. Disabled veterans or qualifying surviving spouses should review the Disabled Veterans’ Exemption separately.
| Exemption or Program | Who Should Review | Key Detail | Official Link |
|---|---|---|---|
| Homeowners’ Exemption | Owners who occupy the home as their principal place of residence on January 1. | San Mateo County Assessor states this may reduce assessed value by $7,000. There is no charge to file. | Homeowners’ Exemption |
| Disabled Veterans’ Exemption | Qualifying disabled veterans, certain 100% disabled veterans, and some unmarried surviving spouses. | The Assessor lists lien-date 2026 exemption amounts and income limits that are subject to annual change. | Disabled Veterans’ Exemption |
| School district parcel tax exemption | Property owners in school districts that place parcel taxes on the bill and offer exemptions. | School districts are responsible for exemption details on their own websites. | Parcel tax exemptions |
| Property Tax Postponement | Eligible senior, blind, or disabled homeowners who need to postpone current-year property taxes on a primary residence. | The State Controller administers the program; applications are accepted October 1 to February 10 each year. | Property Tax Postponement |
| Decline in Market Value / assessment review | Owners who believe assessed value is too high compared with market value. | This is an assessment issue, not a Tax Collector payment issue. | Decline in Market Value |
- Review the eligibility page before filing.
- Confirm the property is your principal residence if applying for the Homeowners’ Exemption.
- Have your property address, mailing address, and Assessor’s Parcel Number ready.
- Use the official Assessor form page or contact the Assessor Division if needed.
Supplemental Property Taxes After Purchase or New Construction
A supplemental tax bill is different from the annual secured bill. San Mateo County explains that supplemental taxes are additional secured taxes due when property undergoes a change in ownership or new construction. The bill reflects the difference between old and new values, adjusted for the months left in the fiscal year.
- Check whether the bill says supplemental, escape, secured, or unsecured.
- Compare the supplemental bill to your purchase date or construction completion date.
- Do not assume the supplemental bill is a duplicate of the annual secured bill.
- Read the installment schedule because delinquent dates depend on when the bill was mailed.
- If your lender collects escrow, ask whether the supplemental bill is included. Many borrowers must pay supplemental bills themselves.
New buyer warning: a supplemental bill may arrive after closing even if your annual secured tax bill or escrow account looks current. Save your closing statement, lender escrow notice, and any supplemental bill together.
New Homeowner Checklist for San Mateo County
New owners often need to solve several tax issues at the same time: annual secured taxes, possible supplemental bills, mailing address updates, Homeowners’ Exemption forms, escrow instructions, and seller-credit confusion.
Unsecured Property Taxes: Business Equipment, Boats, Aircraft, and More
Unsecured property taxes are different from secured real estate taxes. San Mateo County explains that unsecured property can include property that can be relocated and is not real estate, such as business equipment, fixtures, boats, and airplanes. If unpaid, the tax is assessed against the owner, and a personal lien may be filed.
| Topic | Unsecured Tax Rule | What to Do |
|---|---|---|
| Tax lien date | The Assessor establishes value on January 1. | Keep ownership and asset records for that date. |
| Typical bill timing | Most unsecured bills are mailed before July 31. | Pay by 5:00 p.m. August 31 unless the bill has a different extended delinquent date. |
| Penalty | Late payment can add a 10% penalty and $35 collection fee, with later monthly penalties. | Do not ignore unsecured bills, even if the property was sold after January 1. |
| Sold property | Selling after January 1 does not remove the tax liability. | Collect an estimated tax amount from the buyer when appropriate. |
- Confirm whether your bill is unsecured, not annual secured real estate tax.
- Check the mailing date and delinquent date shown on the bill.
- Call the Tax Collector if the property was sold, moved, or transferred.
Late Penalties and Penalty Appeal
San Mateo County follows California Revenue and Taxation Code rules for delinquent penalties and fees. Penalty waivers are not automatic. The Tax Collector may consider waiver requests only in specific circumstances, and the office lists several reasons that do not qualify.
The Tax Collector page says requests based on payment history are not a valid reason for penalty cancellation.
The office considers the USPS postmark, not the date you dropped the envelope in an outgoing mailbox.
The official penalty appeal page says financial circumstances are not considered under the cited rules.
Incorrect information or processing issues caused by taxpayer error may not support an appeal.
- Read the official penalty appeal page first.
- Check whether your reason fits the listed legal criteria.
- Gather supporting documents before submitting the form.
- Follow the Tax Collector’s payment instructions for original tax and penalty/fee amounts.
Assessment Appeals: When the Problem Is Value, Not Payment
If the issue is the assessed value, property classification, decline in market value, change in ownership, or new construction value, the payment office is not the first place to solve it. Payment status is handled by the Tax Collector, while assessed value questions usually start with the Assessor or Assessment Appeals Board.
- Read the assessment notice and compare the property details.
- Check whether the problem is value, classification, exemption, or payment status.
- If value is the issue, review Assessor resources and the Assessment Appeals Board filing period.
- Keep payment deadlines separate from appeal deadlines.
- Do not skip payment just because an appeal is being considered.
Important: filing or considering an appeal does not automatically stop tax collection. Check official payment rules if a bill is due.
San Mateo County Property Tax Rate and Rate Book
The basic property tax calculation is not just one number. The Tax Collector describes tax amounts as the January 1 value established by the Assessor multiplied by the tax rate, usually 1% plus voter-approved indebtedness, with special charges added. The Controller publishes the Property Tax Rate Book, which includes valuations, homeowners property tax exemptions, and property tax rates.
- Open the Controller’s Property Tax Rate Book page.
- Select the current tax-year publication.
- Review tax rates and valuation summaries for context.
- Use your tax bill and parcel details to understand which rate area applies.
If Your Mortgage Company Pays Your Taxes
Mortgage escrow does not remove the need to check payment status. Your lender may collect escrow money monthly, but the county payment must still post before the deadline. This matters most near December 10 and April 10.
- Look up the property by parcel number or address.
- Open the current tax bill and payment status.
- Compare the amount due with your mortgage escrow statement.
- Check whether the lender’s payment has posted before the delinquent date.
- If payment is missing near the deadline, contact the servicer and ask for proof of payment.
- Do not pay personally until you know whether the escrow payment is pending.
Refunds, Overpayments, and Duplicate Payments
Refund questions can happen after duplicate payments, escrow mistakes, appeal changes, supplemental corrections, or overpayments. The Assessor’s property tax bills and refunds page says current or delinquent taxes can be found through the Treasurer/Tax Collector website or by calling 866-220-0308, and refund inquiries may require contacting the Controller with property details.
- Search the property tax record and verify payment status.
- Compare owner payment, lender payment, bank records, and confirmation emails.
- Save the APN, property address, tax year, and payment proof.
- If a refund notice was received, keep the notice and call the appropriate office with details ready.
- For refund explanation, be ready with your name, property address, and APN.
Delinquent Taxes, Tax Sale Risk, and Old Balances
If secured taxes stay unpaid, the situation can become more serious. San Mateo County property tax glossary information explains that secured taxes are assessed against real property and that property may be sold to cover taxes owed if taxes remain unpaid after a period of years.
Urgent note: if your bill mentions delinquent taxes, tax sale, redemption, bankruptcy, foreclosure, probate, or a legal deadline, do not rely only on a general article. Contact the official office or a qualified professional quickly.
- Search the parcel and identify which tax year is unpaid.
- Check whether penalties, costs, or redemption charges have been added.
- Contact the Tax Collector if the parcel shows older delinquent taxes.
- Keep proof of all payments and office communications.
- Use official tax sale information if the property is in a tax-sale process.
Mailing Address Problems
A wrong mailing address can cause missed bills, late notices, refund problems, and exemption mail delays. If you bought a home, moved, inherited a property, or changed mailing arrangements, check the address tied to the property tax record.
- Look up the property tax record.
- Check where the bill or tax notice is being mailed.
- If wrong, use the official change-of-address process.
- Keep a copy or confirmation of the address update.
Before You Visit the Tax Collector’s Office
In-person help is useful when payment status, mailed payment proof, duplicate payment, refund confusion, or account-specific questions cannot be solved online. Bring documents so the visit is productive.
Assessor’s Parcel Number, property address, tax year, installment, and bill copy.
Confirmation number, canceled check image, bank statement, credit card receipt, postmark proof, or escrow statement.
Homeowners’ Exemption form, Disabled Veterans’ Exemption records, mailing address update, or Assessor correspondence.
Photo ID and documents showing your relationship to the property if the issue is owner-specific.
Main office: San Mateo County Tax Collector, 555 County Center, Floor 1, Redwood City, CA 94063. Phone hours and office hours are listed as Monday–Friday, 9:00 a.m. to 5:00 p.m., excluding holidays.
Official San Mateo County Property Tax Links
Use these official sources when you are ready to complete an account-specific action such as payment, lookup, exemption filing, appeal, address change, or refund follow-up.
San Mateo County Tax Collector Office Map
Use the map below for in-person payment or account-specific help. Check office hours, holidays, and accepted payment rules before visiting.
San Mateo County Tax Collector
555 County Center, Floor 1
Redwood City, CA 94063
Phone: 866-220-0308
Email: taxmaster@smcgov.org
Related Property Tax Guides
These internal guides can help you understand general property-tax concepts before taking action on the official San Mateo County website.
Editorial Trust and Update Notes
CountyPropertyTaxes.us is an independent informational guide. It is not the San Mateo County Tax Collector, Assessor, Controller, Clerk-Recorder, or Assessment Appeals Board. This page explains the process and helps users prepare before taking account-specific action on official sites.
Update checklist: due dates, payment fees, e-check/card rules, office address, mailing address, exemption amounts, disabled veteran exemption limits, supplemental bill rules, unsecured tax rules, penalty appeal criteria, tax-rate publications, and official links should be reviewed whenever San Mateo County updates its official pages.
San Mateo County Property Tax FAQs
How do I pay San Mateo County property tax online?
Open the official San Mateo County Tax Collector view/pay system, search by parcel number or address, confirm the tax year and installment, then choose e-check or card. Save the confirmation after payment.
Is there a fee to pay San Mateo County property tax online?
E-check payments have no charge. Credit card payments have a 2.35% service fee processed by the payment service.
When are San Mateo County secured property taxes due?
The first installment is due November 1 and becomes delinquent after 5:00 p.m. December 10. The second installment is due February 1 and becomes delinquent after 5:00 p.m. April 10.
What happens if I miss the first installment deadline?
A 10% penalty is added after the first installment becomes delinquent. Use official payment status and penalty information before sending payment.
What happens if I miss the second installment deadline?
If the second installment remains unpaid after the April 10 deadline, a 10% penalty and a $40 cost are imposed.
How do I find my San Mateo County property tax bill?
Use the Tax Collector’s online property tax system or the Assessor property tax lookup page. Search by Assessor’s Parcel Number or address and confirm the parcel before paying.
What if I did not receive my San Mateo County tax bill?
Annual secured tax bills are mailed by November 1. If you do not receive a bill, use the online property system to determine the amount due or call 866-220-0308 for help.
Can I pay San Mateo County property tax by mail?
Yes. Include the proper payment coupon and make sure the envelope has a United States Postal Service postmark on or before the delinquent date.
Is a private postage meter date enough for mailed payment?
No. California law requires the Tax Collector to accept the USPS postmark, not a private postage meter date, as the payment date.
What is the San Mateo County Homeowners’ Exemption?
If you own and occupy a home as your principal residence on January 1, you may apply for a $7,000 exemption from assessed value. There is no charge to file.
Does San Mateo County offer a Disabled Veterans’ Exemption?
Yes. The Assessor lists Disabled Veterans’ Exemption information, including lien-date 2026 exemption amounts and income limits that are subject to annual change.
What is a supplemental property tax bill?
A supplemental tax bill is an additional secured tax bill issued after a change in ownership or new construction. It reflects the difference between old and new assessed values for part of the fiscal year.
Do supplemental tax bills come through escrow?
Not always. New owners should ask their lender or escrow servicer whether supplemental taxes are included. Many homeowners must handle supplemental bills separately.
Who handles San Mateo County property tax values?
The Assessor determines the underlying property value. The Tax Collector handles billing and collection, while the Controller calculates and distributes tax amounts.
How do I appeal my assessed value?
Review Assessor resources and the Assessment Appeals Board. Keep appeal deadlines separate from property tax payment deadlines.
What are unsecured property taxes?
Unsecured property taxes apply to property that is not real estate and can be relocated, such as business equipment, fixtures, boats, and airplanes.
What should I do if my mortgage company pays my taxes?
Still check online payment status before each delinquent date. Escrow collection does not always mean the county payment has posted.
Where is the San Mateo County Tax Collector office?
The main office is at 555 County Center, Floor 1, Redwood City, CA 94063. The main phone number is 866-220-0308.
Is CountyPropertyTaxes.us the official San Mateo County tax office?
No. This is an independent informational guide. Final payments, filings, appeals, and account-specific verification should be completed through official San Mateo County systems.
Bottom Line
Search the parcel first, confirm the bill, check the due date and installment, review payment status and exemptions, then use the official San Mateo County Tax Collector or Assessor page only for final action.
Find My BillPay Property TaxDue DatesExemptionsOfficial Links