Sales Tax in San Mateo, California in 2025

We'll walk you through how the sales tax rate is determined for San Mateo and address some common questions you may have. We'll also cover how to collect, audit, and remit sales tax in San Mateo.

Plus, we’ll share the best solution that will ensure you are always compliant across the entire sales tax lifecycle.

Disclaimer: Our sales tax data is updated on a quarterly basis.

San Mateo Sales Tax Rate 2025

San Mateo is located in San Mateo County in California, United States, and has a sales tax rate of 9.375%-9.625%. This includes local and state sales tax rates.

Here is the breakdown of the San Mateo's sales tax:

Sales Tax Rates in San Mateo by Zip Codes and Districts

Let’s see the sales tax rates in San Mateo broken down by zip codes and districts:

How Does the San Mateo Sales Tax Compare to the Rest of California?

San Mateo’s 9.375%-9.625% sales tax rate is 1.625% lower than the highest sales tax rate in California, which stands at 11.25% in cities like Palmdale.

It is 2.125% higher than the lowest sales tax rate in California, which stands at 7.25% in cities like Adin.

To give you a better idea, here’s a comparison of San Mateo sales tax rates with a few other cities in California:

What Creates Sales Tax Nexus in San Mateo?

San Mateo follows the California state sales tax law, as it’s located in California. There are no separate nexus rules specifically for San Mateo other than the California state tax law.

Read More: Check out this detailed guide on Sales Tax in California.

California state sales tax nexus rules include:

• Economic Nexus: When a business sells goods worth $500,000 or more in the state within the previous or current tax year.
• Physical Location: This could be a warehouse, office, or distribution center.
• Employee Location: If a company has employees or any other type of representation in a particular state or city, they should pay taxes.
• Affiliate Nexus: When an out-of-state business receives substantial referrals from in-state businesses.
• Trade Shows: Businesses with a physical presence at trade shows for over 15 days within one calendar year.
• Tangible Personal Property: Sales of more than $500,000 worth of personal property like equipment, supplies, or IT systems in the previous or current tax year.

What Products Are Exempt from San Mateo Sales Tax?

The following tax exemptions are granted by the California sales tax law and apply to San Mateo as well. (There are no separate exemptions for San Mateo taxpayers.)

• Groceries
• Diapers
• Feminine hygiene products
• Digital services
• SaaS (if there is no transfer or sale of tangible personal property)
• Services like content writing, digital marketing, videography, and software building projects. However, there is an exception. If these services are closely connected to the sale of a physical product, such as equipment assembly, fabrication, or set-up, they may be taxable in California.

Who Needs a Sales Permit in San Mateo?

A sales permit or seller's permit is typically issued by states in the United States. You can apply for one in California through the CDTFA website. A seller's permit allows you to collect and remit sales tax on your products.

You need one if you:

• Operate as a wholesaler or retailer and conduct business in San Mateo or anywhere in California.
• Plan to sell or lease tangible personal property that’s usually taxable if sold in retail.

How to Collect Sales Tax in San Mateo

Since California is a modified origin-based sales tax state, the same applies to San Mateo as well. According to California sales tax law, two different tax types apply to most sales:

• Sales and use tax: Sales tax is imposed on the sales of products and services. If your clients haven't paid sales tax, you may need to collect and remit use tax on their behalf when they purchase goods.
• District transaction tax: It’s an additional local sales tax imposed on specific state districts on certain transactions. District taxes are approved by voters.

How to File and Pay Sales Tax in San Mateo

Taxpayers have two options for filing and paying San Mateo sales tax returns:

• Pay your sales tax in San Mateo by filing your statewide sales tax return online at the California Department of Tax and Fee Administration Website. Once you file your return, the state will then remit the appropriate amount to the counties and cities. If you prefer in-person assistance with your taxes, you can visit the Internal Revenue Service (IRS).
• Or, you can say goodbye to the tedious paperwork and hello to stress-free sales tax management with Zamp. We help you automate sales tax filings, check your transactions, and manage the nitty-gritty of ongoing compliance without a third-party - wherever you are in the United States!

With our white-glove onboarding, rooftop accurate calculations, proactive nexus monitoring, expert tax professional services, and click-to-approve sales tax registrations & filings, we take care of all the sales tax responsibilities for you. You can focus on your business and clients without worrying about the complexities of sales tax. We also ensure that you always stay compliant.

About the author

Zamp Team

The Zamp Team consists of experienced writers and editors who are dedicated to researching sales tax topics to help readers make smart decisions about their business and sales tax compliance. Collectively, the team has over 200 years of sales tax experience..