91765 Sales Tax Rate for Diamond Bar, California

The 91765 sales tax rate for Diamond Bar, California is 9.75 percent.1California Department of Tax and Fee Administration. California City and County Sales and Use Tax Rates That rate took effect on April 1, 2025, and it applies to taxable purchases anywhere inside the ZIP code. On a $100 purchase, the tax is $9.75. On a $500 laptop, it adds $48.75.

Retailers in Diamond Bar collect the full 9.75 percent on qualifying sales and send it to the California Department of Tax and Fee Administration (CDTFA). The rate is the same whether you’re at a big-box store, a local shop, or a car dealership. To confirm the rate at a specific address, the CDTFA has an online lookup tool that searches by street address or intersection.2California Department of Tax and Fee Administration. Find a Sales and Use Tax Rate

How the 9.75 Percent Breaks Down

California’s statewide base sales and use tax rate is 7.25 percent.3California Department of Tax and Fee Administration. Know Your Sales and Use Tax Rate That base funds the state general fund, local public safety, and county transportation, and it applies everywhere in California. Los Angeles County adds another 2.50 percent on top through voter-approved district taxes, which is how Diamond Bar lands at 9.75 percent.

Five separate half-cent measures make up the county’s 2.50 percent:

  • Proposition A (1980), a transit tax.4LA Metro. Propositions A and C
  • Proposition C (1990), funding transit-related highway improvements, rail and bus security, and commuter rail.4LA Metro. Propositions A and C
  • Measure R (2008), which expanded the Metro rail network.5Los Angeles County Metropolitan Transportation Authority. Local Return
  • Measure M (2016), funding long-range transit construction.5Los Angeles County Metropolitan Transportation Authority. Local Return
  • Measure A (2025), funding homelessness services, affordable housing, rental assistance, and mental health treatment.6City of El Segundo. LA County Sales Tax Rate Change – Effective April 1, 2025

Why the Rate Went Up in April 2025

Measure A replaced the older Measure H, which was a quarter-cent tax set to expire in 2027. Measure A doubled that levy to a full half-cent and removed the expiration date, pushing Diamond Bar’s combined rate from 9.50 percent to 9.75 percent. The increase is permanent unless voters repeal it.6City of El Segundo. LA County Sales Tax Rate Change – Effective April 1, 2025

What You Actually Pay the Rate On

California taxes sales of tangible personal property, which is the legal term for physical goods you can see or touch. Clothing, electronics, furniture, appliances, and sporting goods all carry the full 9.75 percent in Diamond Bar. If you can hold it in your hands or need a truck to get it home, assume it’s taxable unless an exemption applies.

Groceries and Prepared Food

Most grocery items are exempt. The exemption covers fruits, vegetables, meat, dairy, cereals, eggs, coffee, and bottled water, among other food products for human consumption.7California Legislative Information. California Code RTC 6359 – Food Products; Exemption; Conditions It disappears when food is sold as a prepared meal, served for on-site consumption, or sold through a vending machine. Cold groceries from the supermarket are tax-free. A hot sandwich from the deli counter or a restaurant meal is not.

Prescription Medicine

Prescription medicines dispensed by a pharmacist or furnished by a licensed physician are exempt.8California Department of Tax and Fee Administration. Regulation 1591 Over-the-counter drugs you pull off the shelf without a prescription are taxable. Certain medical devices such as insulin syringes and prosthetics also qualify for exemption, though the device-level rules can get specific.

Services

Labor and professional services are generally not subject to sales tax in California. A plumber’s time, a consultant’s advice, or an accountant’s work on your return are not taxable transactions. The line blurs when a service produces a physical product, like custom-built furniture, where the materials are taxed even if the labor isn’t.

Online, Out-of-State, and Vehicle Purchases

When you buy something online or from an out-of-state seller that doesn’t collect California tax, you still owe use tax at the same 9.75 percent rate.9California Department of Tax and Fee Administration. California Use Tax Most large online retailers now collect California tax automatically, but smaller sellers, private-party out-of-state purchases, and items bought while traveling can slip through. The easiest way to report what you owe is on your California income tax return, which has a dedicated line for it. If you haven’t tracked individual purchases, the CDTFA publishes a Use Tax Lookup Table that estimates the amount based on your income.3California Department of Tax and Fee Administration. Know Your Sales and Use Tax Rate There’s no minimum purchase threshold; every dollar of untaxed goods technically triggers the obligation.

If your annual untaxed purchases exceed $10,000 (excluding vehicles, vessels, and aircraft), California classifies you as a “qualified purchaser” and requires you to register directly with the CDTFA to report and pay use tax, rather than reporting it on your income tax return.10California Department of Tax and Fee Administration. Qualified Purchaser Program The threshold mostly affects businesses, but an individual making large out-of-state purchases can hit it too.

Buying a Car

Vehicles work differently from most other goods. The use tax on a vehicle purchase is based on the address where you register the vehicle, not the location of the dealership.11California Department of Tax and Fee Administration. Tax Guide for Purchasers of Vehicles If you live in Diamond Bar and register the car in 91765, you pay 9.75 percent regardless of where you bought it. Dealerships collect the tax at sale; the DMV collects it at registration if you bought from a private party or an out-of-state seller. Driving to a lower-rate city to buy a car doesn’t save you anything, because the tax follows your registration address.

For Businesses Collecting the Tax

Any business selling or leasing physical goods in Diamond Bar needs a California seller’s permit before the first sale. The permit itself is free, though the CDTFA may require a security deposit depending on the business.12California Department of Tax and Fee Administration. Your California Seller’s Permit Out-of-state sellers must also register once their total sales into California exceed $500,000 in the current or preceding calendar year, and California uses only that dollar test, not a transaction count.13California Department of Tax and Fee Administration. Use Tax Collection Requirements Based on Sales into California Businesses buying inventory for resale can avoid paying tax at purchase by giving the supplier a resale certificate with their seller’s permit number and a description of the goods; the tax then gets collected when the finished item is sold to the end customer.14Taxes (California). Resale Certificates Using a resale certificate for items you actually keep is a fast route to penalties in an audit.