San Mateo County Property Tax Lookup, Online Payment, Rates and Appeal Help
A practical San Mateo County California property tax guide for homeowners, buyers, landlords and investors who need to search secured taxes, pay online, find parcel information, understand due dates, review tax rates, check exemptions or file an assessment appeal.
🔒 Official San Mateo County Property Tax Resources
San Mateo County Property Tax Lookup, Payment and Assessment Basics
San Mateo County property tax is easier when you separate payment questions from assessment questions. The Tax Collector handles bills, payment, payment plans and collection. The Assessor handles value, parcel information and property assessment records.
The secured property tax bill is normally paid in two installments. The first installment is due November 1 and becomes delinquent after December 10. The second installment is due February 1 and becomes delinquent after April 10.
For lookup, San Mateo County resources direct users to the Treasurer-Tax Collector’s secured property tax search, where you can find property tax by searching by address or parcel number and pay online by ECheck or credit card.
| Need | Best Official Place | What You Can Do |
|---|---|---|
| Pay secured tax | San Mateo County Tax Collector | Pay secured property taxes online, by mail, or through official county payment options. |
| Search tax bill | Property Tax Look-up | Search by property address or Assessor’s Parcel Number. |
| Find parcel map | GIS property maps / Assessor resources | Search parcels by address or APN and view assessor maps. |
| Review value | Assessor | Review assessed value, ownership date, parcel data and assessment questions. |
| Appeal value | Assessment Appeals Board | File regular, supplemental, escape or calamity reassessment appeal when eligible. |
How to Look Up San Mateo County Property Tax by Address or Parcel Number
The fastest San Mateo County property tax lookup method is to use the official secured property tax search and confirm the property by address or Assessor’s Parcel Number before payment.
1
Open the official property tax lookup resource
Best for current secured tax bill and payment status
Start from the San Mateo County Assessor’s property tax look-up page or the Tax Collector website. The county explains that the secured property tax search can find property tax by searching by address or parcel number.
Before payment, confirm the parcel, owner, property address, tax year, installment and delinquency status.
2
Use parcel maps when address search is unclear
Best for condos, vacant land, split parcels and boundary checks
San Mateo County GIS property maps allow users to search parcels by address or APN and view property maps and assessor maps.
This is helpful if your address has unit numbers, similar street names, recent subdivision, or parcel boundary confusion.
3
Verify Assessor information separately
Payment amount and assessment value are related but different
If your issue is assessed value, ownership, parcel information or exemption status, use Assessor resources. The payment screen tells you what is due; the assessment record helps explain why the bill exists.
For recent purchases or new construction, also watch for supplemental assessment notices because they can create separate bills.
4
Save bill details before paying
Useful for escrow, refinance, appeal and records
Save the parcel number, tax year, installment, amount due, penalty status, direct charges, payment method and confirmation. Keep the tax bill and receipt together.
How to Pay San Mateo County Property Taxes Online and Avoid Penalties
San Mateo County property taxes can be paid through official Tax Collector resources. The county lists online payment options and notes that property tax payments can also be mailed to the Tax Collector’s payment mailing address.
ECheck payment
Useful for online payment when you want to avoid some card-style percentage fees. Read the official fee screen before paying.
Credit card / PayPal
Convenient for fast payment, but San Mateo County notes online service fees may apply for certain payment methods.
1
Start from the Tax Collector website
Use official route only
Open the San Mateo County Tax Collector website and choose the view/pay property taxes option. No login is needed for the property tax payment search link shown by the county.
2
Pay the correct installment before the delinquency date
California secured tax bills use two installments
The first installment is due November 1 and becomes delinquent after December 10. The second installment is due February 1 and becomes delinquent after April 10.
After the delinquency time, a 10% penalty is added. The second installment can also include an additional cost if unpaid after April 10.
3
Use the correct mailing address for checks
Mail payment address is different from office address
San Mateo County Tax Collector lists check payments payable to Sandie Arnott, San Mateo County Tax Collector.
The county lists mail tax payments to: San Mateo County Tax Collector, PO Box 45878, San Francisco, CA 94145-0878.
4
Save receipt and recheck posting
Important for escrow, refinance and late-fee disputes
Save the confirmation number, parcel number, tax year, installment, amount paid and payment method. Recheck the account after processing to confirm the payment posted.
If your mortgage company pays through escrow, check the county account before December 10 and April 10. Lender mistakes are easier to fix before penalty dates.
San Mateo County Property Tax Rates and Calculator Basics
California property tax is commonly built around the Proposition 13 general 1% property tax framework, but a San Mateo County tax bill can also include voter-approved debt, direct levies, special assessments and parcel-level charges.
That is why two properties with similar assessed values can have different bills. City, school district, bond, sewer, lighting, landscape, community facilities or other direct charges may appear differently by parcel and location.
Assessed value
The Assessor’s value used for property tax calculation.
General tax
Often begins with California’s general 1% property tax framework.
Direct charges
Special assessments and parcel charges can change the final bill.
| Bill Component | Where to Check | Why It Matters |
|---|---|---|
| Assessed value | Assessor / tax bill | Starting value for tax calculation and appeal review. |
| Parcel number | Tax bill / Assessor map | Needed to identify exact bill and parcel. |
| General levy | Tax bill | Base property tax amount before added charges. |
| Voter-approved debt | Tax bill details | Can increase bill above a simple 1% estimate. |
| Direct charges | Tax bill | Parcel-specific charges can explain bill differences. |
| Supplemental bills | Assessor / Tax Collector | New owners or new construction may receive separate bills. |
San Mateo County Homeowner Exemption, Disabled Veterans Exemption and Supplemental Tax Checks
San Mateo County homeowners should check exemptions and supplemental tax risk after purchase, transfer, major remodel or new construction. Regular secured tax bills and supplemental bills are not the same.
Homeowners’ exemption
California exemption may reduce assessed value for eligible owner-occupied homes.
Disabled veterans’ exemption
May provide larger relief for eligible disabled veterans or surviving spouses.
Supplemental bills
Purchase or new construction can create separate supplemental tax bills.
1
Check exemption status after buying
Do not assume closing paperwork handles everything
If the home is your principal residence, review whether a homeowners’ exemption claim is needed or already applied. If you are a disabled veteran or surviving spouse, check disabled veterans’ exemption rules.
Exemption status can affect tax savings, but it does not cancel payment deadlines. Keep paying any bill that is due unless official county guidance tells you otherwise.
2
Expect supplemental bills after ownership change
A new buyer may receive more than one tax bill
In California, a purchase or new construction can trigger supplemental assessment and separate supplemental tax bills. These are in addition to the regular secured bill.
If you recently bought property in San Mateo County, keep your closing statement, deed recording date, purchase price and property tax estimates in one folder.
3
Use the right appeal window for supplemental notices
Supplemental deadlines are shorter than regular appeals
San Mateo County Assessor appeal guidance says appeals on supplemental assessments must be filed within 60 days of the mailing date on the supplemental assessment notice.
Do not wait until the annual November 30 regular appeal deadline if your issue is supplemental assessment.
San Mateo County Assessment Appeal and Value Review Help
If you disagree with the assessed value of your property, San Mateo County allows you to initiate an assessment appeal. Regular assessment appeals are generally filed July 2 through November 30, while supplemental and escape assessment appeals follow separate 60-day deadlines.
Value too high
Use comparable sales, appraisal reports and market evidence.
Supplemental issue
Check purchase date, new base-year value and notice mailing date.
Property data wrong
Check size, use, condition, land area and improvement details.
1
Review the assessed value and notice type
Regular, supplemental, escape and calamity appeals have different timing
Identify whether your issue is regular annual assessment, supplemental assessment, escape assessment or calamity reassessment. San Mateo County appeal preparation guidance lists different filing dates for each type.
If the issue is simple property data, contact the Assessor early. If the disagreement remains, prepare a formal appeal.
2
File regular assessment appeals between July 2 and November 30
Do not miss the annual filing period
San Mateo County assessment appeal guidance states that appeals on annual assessments must be filed between July 2 and November 30.
For 2025, the county noted that November 30 fell on a Sunday, so the deadline rolled to Monday, December 1, 2025. Check the current year’s calendar before filing.
3
Use 60-day deadline for supplemental or escape assessment notices
Notice date controls the clock
San Mateo County appeal resources state that supplemental and escape assessment appeals are generally due within 60 days from the date shown on the notice.
Save the notice, envelope, mailing date, parcel number and evidence. The deadline may arrive much sooner than the annual appeal window.
4
Prepare evidence before hearing
A strong appeal uses facts, not only complaint
Prepare comparable sales, appraisal report, photos, repair estimates, inspection reports, listing history, closing statement, building permit details and proof of incorrect property characteristics.
Pay attention to valuation date. For supplemental assessment, purchase date and transfer date can matter.
Real San Mateo County Property Tax Tips That Prevent Costly Mistakes
San Mateo County tax users often mix up payment, parcel lookup, supplemental assessments, exemptions and appeal deadlines. These practical checks keep the process clean.
Use APN for exact lookup
Address search can be messy. The parcel number is usually safer for exact tax bill search and parcel map review.
Watch December 10 and April 10
These are the two major secured tax delinquency dates. Missing either can add a 10% penalty.
Do not ignore supplemental bills
New buyers may receive separate supplemental tax bills after purchase or new construction. These are not the same as the regular secured bill.
Use mail address correctly
Office address and payment mailing address are different. Use the county-listed PO Box for mailed tax payments.
Appeal by notice type
Regular assessment appeals use July 2-November 30. Supplemental and escape appeals usually use 60 days from notice date.
Check direct charges
A high bill may include voter-approved debt or direct charges, not only the general 1% tax.
San Mateo County Property Tax Due Dates, Penalties and Appeal Calendar
San Mateo County property owners should track secured tax installment deadlines, supplemental notice deadlines and annual assessment appeal filing periods separately.
| Date / Timing | Common Event | What You Should Do |
|---|---|---|
| January 1 | Tax lien date | Ownership and value status are determined as of this date for many assessment purposes. |
| July 2 | Regular assessment appeal filing period opens | File regular assessment appeal if value evidence supports it. |
| November 1 | First secured installment due | Review tax bill and pay before the delinquency deadline. |
| November 30 | Regular assessment appeal filing period generally closes | Check if the date rolls when it falls on weekend or holiday. |
| December 10 | First secured installment delinquent after this date | Pay before 5 p.m. or close of business deadline to avoid 10% penalty. |
| February 1 | Second secured installment due | Confirm escrow or payment plan status. |
| April 10 | Second secured installment delinquent after this date | Pay before deadline to avoid penalty and added cost. |
| Within 60 days | Supplemental or escape assessment appeal window | Use the notice date and file quickly if disputing the assessment. |
San Mateo County Tax Collector, Assessor and Appeal Office Help
Use the Tax Collector for bill, payment, payment plans, mailing address and delinquency. Use the Assessor for parcel and assessed value questions. Use the Assessment Appeals Board for formal appeals.
San Mateo County Tax Collector
555 County Center, Floor 1, Redwood City, CA 94063
Phone: 866-220-0308 • Email: taxmaster@smcgov.org
San Mateo County Property Tax Questions and Answers
These answers cover common searches like San Mateo County property tax lookup, online payment, secured tax due dates, parcel search, rates, penalties, supplemental taxes and assessment appeals.
Where do I pay San Mateo County property taxes online?▾
Use the official San Mateo County Tax Collector website or secured property tax search. The county offers online property tax payment options through official resources.
How do I look up San Mateo County property tax by address?▾
Use the county property tax look-up resource. San Mateo County says the secured property tax search can find property tax by searching by address or parcel number.
When are San Mateo County secured property taxes due?▾
The first installment is due November 1 and becomes delinquent after December 10. The second installment is due February 1 and becomes delinquent after April 10.
What is the late penalty for San Mateo County property tax?▾
A 10% penalty is added after the secured installment delinquency deadline. The second installment can also include an added cost if unpaid after April 10.
Who handles San Mateo County property value questions?▾
The San Mateo County Assessor handles assessed value, parcel information, property records and assessment-related questions.
Where is the San Mateo County Tax Collector office?▾
The office is located at 555 County Center, Floor 1, Redwood City, CA 94063. The county lists phone number 866-220-0308 and email taxmaster@smcgov.org.
How do I calculate San Mateo County property tax?▾
Start with assessed value and California’s general 1% property tax framework, then add voter-approved debt, direct levies, special assessments and other parcel-level charges shown on the official tax bill.
How do I appeal a San Mateo County property assessment?▾
Regular assessment appeals are generally filed July 2 through November 30. Supplemental and escape assessment appeals are generally due within 60 days of the notice date.
What is a San Mateo County supplemental tax bill?▾
A supplemental bill may be issued after a change in ownership or new construction. It is separate from the regular secured bill and has separate deadline and appeal timing.
Is PropertyTaxUSA.org an official San Mateo County website?▾
No. PropertyTaxUSA.org is an independent informational guide. Always use official San Mateo County Tax Collector, Assessor and Assessment Appeals resources for property-specific actions.
Before You Pay or Appeal San Mateo County Property Taxes
Search the official secured property tax record first, confirm the APN, tax year, installment and amount due, then verify Assessor parcel details if the value or property record looks wrong.
If the issue is payment, mailing address, installment, receipt or delinquency, use the Tax Collector. If the issue is value, parcel data or exemption, use the Assessor. If the issue requires formal value review, use the Assessment Appeals Board before the correct filing deadline.