If you sell products from a shop, a warehouse or a website in Union City, your sales tax work peaks right when you are busiest. Holiday sales, pop-up events and online orders all land in the fourth quarter, and the return that reports them is due in early 2027. Getting Union City sales tax right means charging the correct rate on every order, filing on the schedule the California Department of Tax and Fee Administration (CDTFA) assigned you, and keeping records that support each deduction.
Accountico Inc. is a CPA firm in Union City, CA that works with business owners in Fremont, Newark, Hayward, San Leandro, Castro Valley and across the Bay Area. This guide is general information based on CDTFA guidance available as of October 8, 2026. It is not tax advice for your specific situation.
What is the Union City sales tax rate in 2026?
According to CDTFA’s city and county sales and use tax rates effective October 1, 2026, the Union City sales tax rate is 10.75%. That total is built from three layers:
- 7.25% statewide base rate. CDTFA’s rate breakdown shows 6.00% going to the state and 1.25% going to local governments (1.00% for city or county operations and 0.25% for county transportation).
- 3.00% Alameda County district taxes. Six countywide taxes of 0.50% each: Bay Area Rapid Transit, Essential Health Care Services, Children’s Health and Child Care, the Alameda County Transactions and Use Tax, and two Alameda County Transportation Commission taxes.
- 0.50% City of Union City Transactions and Use Tax. CDTFA’s active district tax list shows it operative since April 1, 2011, with a sunset date of March 31, 2034.
Rates in neighboring cities are close but not identical, which matters if you deliver across the Tri-City area:
- Union City, Hayward, Newark and San Leandro: 10.75%, because each city adds its own 0.50% district tax.
- Fremont: 10.25%, the Alameda County rate, because Fremont does not add a city district tax.
- Castro Valley and other unincorporated areas: 10.25%, the unincorporated Alameda County rate.
A mailing address that says “Union City” is not proof that a location is inside the city’s tax boundary. Check specific addresses with CDTFA’s Find a Sales and Use Tax Rate by Address tool and save the result with your records. CDTFA’s lookup for our own office at 33476 Alvarado Niles Road, for example, returns the Union City jurisdiction at 10.75%.
Which rate to charge: in-store, delivered and shipped orders
District tax generally follows the place of sale for over-the-counter sales and the delivery destination for orders you ship or deliver. Under CDTFA Publication 105, the practical rules for a local seller look like this:
- Counter sales in your store inside city limits: charge 10.75%.
- Orders delivered to a location outside every special tax district: generally the 7.25% statewide rate.
- Orders delivered into a district: the full rate for that district, if you are “engaged in business” there. You are engaged in business in a district if you have a store, warehouse, office, sales representatives or installers there, or if your combined California sales of tangible goods exceeded $500,000 in the current or preceding calendar year. Above $500,000, you are treated as engaged in business in every California district.
Illustration: a Union City furniture shop ships a $1,000 table by common carrier to a customer in Fremont. Because the shop has a physical presence in Alameda County, the countywide district taxes apply, and the Fremont rate of 10.25% gives $102.50 of tax, compared with $107.50 at the shop’s 10.75% counter rate. If the same shop ships by common carrier to Hayward, has no presence there and is under the $500,000 threshold, it is not required to collect Hayward’s 0.50% city tax and can charge 10.25%. It may collect Hayward’s tax as a courtesy, but then it must show the tax on the invoice and report it on Schedule A of the return. Delivering in its own truck changes the answer, because a business that makes deliveries in a district is engaged in business there.
Good e-commerce and point-of-sale settings handle most of this automatically, but only if each product, location and ship-to address is set up correctly. A quarterly spot-check of a few invoices against CDTFA’s lookup tool catches most rate errors before they compound.
Who needs a seller’s permit in Union City
CDTFA’s seller’s permit FAQ says you must obtain a seller’s permit if you are engaged in business in California and intend to sell or lease tangible personal property that would ordinarily be subject to sales tax at retail. That applies to individuals, corporations, partnerships and LLCs, and to wholesalers as well as retailers. Key points:
- No fee. There is no charge for a seller’s permit, although CDTFA may require a security deposit based on your business and expected sales.
- Holiday pop-ups and markets. If you do not hold a permit and will sell for a temporary period, generally 90 days or less at one location, you need a temporary seller’s permit. If you already hold a permit for a permanent location, you register a sub-permit for each temporary location instead.
- Occasional sellers. Someone who makes no more than two sales in a 12-month period, such as an occasional garage sale, generally does not need a permit.
- City license is separate. A CDTFA seller’s permit does not replace the business license you get from the City of Union City, Fremont or wherever you operate.
If you are opening a new retail or e-commerce business, our company formation services can set up the entity, the EIN and the state registrations in the right order.
Online sellers, marketplaces and the $500,000 threshold
Many Tri-City businesses sell on Amazon, Etsy, eBay or Walmart Marketplace alongside their own websites. Under CDTFA’s Marketplace Facilitator Act guide, since October 1, 2019 a marketplace facilitator that is registered or required to be registered with CDTFA is generally responsible for the sales or use tax on sales it facilitates for you.
That does not mean marketplace sales disappear from your return. If you are required to be registered, you still report total sales, including marketplace sales, and then claim a deduction as “other” for the sales facilitated by the marketplace. Keep the marketplace’s monthly tax reports as support for that deduction.
For sellers on the other side of the state line, CDTFA’s Wayfair guide explains that out-of-state retailers must register and collect California use tax once their combined sales of tangible goods for delivery in California exceed $500,000 in the current or preceding calendar year. Sales by related businesses count toward that total.
CDTFA filing frequency and Q4 2026 due dates
CDTFA assigns each account a filing frequency based on the tax you report or the taxable sales you expected when you registered: monthly, quarterly, quarterly prepayment, fiscal yearly or yearly. A return is required on or before the due date even if you had no sales.
If your estimated measure of tax liability averages $17,000 or more per month and CDTFA notifies you, you are placed on quarterly prepayments. You prepay at least 90% of the state and local tax liability for each of the first two months of the quarter (the second-quarter rules differ slightly). CDTFA’s example: a month with a $30,000 tax liability requires a $27,000 prepayment.
The official California tax filing calendar and CDTFA’s filing dates page give these dates for the rest of 2026 and early 2027:
- November 2, 2026 (Monday): third quarter 2026 and September monthly returns. The normal October 31 date falls on a Saturday.
- November 24, 2026 (Tuesday): October 2026 prepayment for quarterly prepayment filers.
- November 30, 2026 (Monday): October 2026 monthly returns.
- December 24, 2026 (Thursday): November 2026 prepayment.
- December 31, 2026 (Thursday): November 2026 monthly returns.
- February 1, 2027 (Monday): fourth quarter 2026, December 2026 monthly and 2026 yearly returns. The normal January 31 due date falls on a Sunday.
Timing matters on the due date itself. CDTFA treats an online payment started on the due date as timely only if it is completed before midnight Pacific time, or before 3:00 p.m. Pacific time for electronic funds transfer accounts.
Late filing is expensive. CDTFA Publication 75 lists a 10% penalty for a late return and a 10% penalty for late payment, capped at 10% of the tax for the period when both apply, plus interest for each month or fraction of a month the payment is late. On a fourth-quarter return with $5,000 of tax, that is a $500 penalty before interest. Missed prepayments can trigger a separate 6% penalty.
Use tax on business purchases from out-of-state sellers
Use tax is the other half of the system. CDTFA’s use tax guide explains that when you buy merchandise without California tax from an out-of-state seller and use it in California, you owe use tax on that purchase. Equipment, furniture, supplies and store displays are common examples for small businesses.
- If you hold a seller’s permit, report those purchases under “Purchases subject to use tax” (line 2) on your sales and use tax return for the period you first used the item in California.
- If you do not need a seller’s permit, such as a service business, you may be a qualified purchaser. From January 1, 2024 through December 31, 2028, that applies if you make more than $10,000 of purchases subject to use tax in a calendar year on which no California tax was paid. Qualified purchasers file once a year, so 2026 purchases are due by April 15, 2027.
Illustration: a Union City salon buys $8,000 of styling chairs from an Arizona supplier that does not charge California tax. At the 10.75% local rate, the use tax is $860. The same rule applies to items bought tax-free with a resale certificate and then used in the business instead of resold.
Bookkeeping that keeps your CDTFA returns clean
Most sales tax problems start in the books, not on the return. The CDTFA-401 return instructions require you to report total sales, both taxable and nontaxable, and then support each deduction. That makes clean records essential:
- Resale certificates. Sales to other retailers for resale go on line 4 and need a timely, valid resale certificate taken in good faith, such as a CDTFA-230 general resale certificate. Collect them before the sale, not during an audit.
- Shipping vs. handling. Under Publication 100, separately stated shipping by an independent carrier can be nontaxable, but handling is taxable, and any delivery charge above your actual cost is taxable. Label invoices clearly and keep carrier invoices.
- Tax included in sales. If your sales totals include the tax you collected, deduct it on line 9 or you will overpay.
- Bad debts. Uncollectible taxable sales that you charged off for income tax purposes can be deducted, and any later recovery must be reported.
- Record retention. CDTFA Publication 116 says to keep sales and use tax records for at least four years, longer during an audit or dispute. If your POS system deletes data sooner, export it.
The simplest monthly control is a three-way match: POS or website sales reports, payment processor deposits (Square, Stripe, Shopify Payments, PayPal) and marketplace statements should all tie to the revenue in your general ledger and to line 1 of your CDTFA return. Our bookkeeping services include that reconciliation every month, and our guide on how to organize your books before filing taxes covers the basics. Restaurants have extra wrinkles around tips and service charges, covered in our Bay Area restaurant bookkeeping checklist.
Year-end Union City sales tax checklist
- Confirm your CDTFA filing frequency and whether you are on quarterly prepayments.
- Look up and save the rate for every store, warehouse and event location you use, and confirm your POS charges 10.75% in Union City.
- Check that your e-commerce tax settings use the ship-to address for delivered orders, including Fremont, Hayward and Newark deliveries.
- Register temporary sub-permits for holiday markets or pop-up locations before the first sale.
- Download October, November and December marketplace tax reports for the “other” deduction.
- Collect missing resale certificates from wholesale customers.
- List out-of-state purchases bought without California tax and accrue use tax.
- Calendar November 24 and December 24, 2026 for prepayments and February 1, 2027 for the fourth-quarter or yearly return.
- Reconcile 2026 total sales on your CDTFA returns to the gross receipts on your income tax return, and document any differences.
- Review the rest of your Q4 deadlines with our Fremont small business year-end tax checklist and the California $800 franchise tax guide for Union City.
Frequently asked questions
What is the sales tax rate in Union City, CA?
The Union City sales tax rate is 10.75% as of October 1, 2026. It is made up of the 7.25% statewide rate, 3.00% of Alameda County district taxes and a 0.50% Union City transactions and use tax. Always confirm the rate for a specific address with the CDTFA rate lookup tool.
Is the Union City sales tax rate higher than Fremont’s?
Yes. CDTFA lists 10.25% for Fremont and 10.75% for Union City, Hayward, Newark and San Leandro. Unincorporated areas such as Castro Valley use the 10.25% Alameda County rate. The difference comes from city-level district taxes.
When is the fourth quarter 2026 CDTFA sales tax return due?
The normal due date is January 31, 2027, but that date is a Sunday, so returns for the fourth quarter of 2026, for December 2026 monthly filers and for 2026 yearly filers are due Monday, February 1, 2027. Quarterly prepayment filers also owe prepayments by November 24 and December 24, 2026.
Do I have to file a CDTFA return if I had no sales this quarter?
Yes. CDTFA requires a return on or before the due date even if you have no sales to report. You do not need to send a zero payment when no tax is due, but the return itself must be filed.
Do I report Amazon or Etsy sales on my California sales tax return?
If you are required to be registered with CDTFA, report your total sales, including sales made through a marketplace. You can then claim a deduction as other deductions for sales facilitated by a registered marketplace facilitator, because the marketplace is responsible for the tax on those sales.
Does Accountico help Union City businesses with sales tax?
Yes. Accountico Inc. is a CPA firm in Union City that helps retailers, restaurants, contractors and online sellers in Union City, Fremont, Newark, Hayward, San Leandro, Castro Valley and the Bay Area keep sales tax records, reconcile sales channels and prepare CDTFA returns alongside their bookkeeping and income tax work.
Get your Union City sales tax right before February 1, 2027
Union City sales tax is manageable when the rate settings, the books and the CDTFA calendar line up. Accountico’s Union City team handles monthly bookkeeping and sales tax reconciliation, business tax preparation and year-end tax planning for retailers, restaurants and online sellers across the Tri-City area and the Bay Area.
Book a free 30-minute consultation, call (510) 400-9341, or contact our Union City team.
This article is general information based on California Department of Tax and Fee Administration guidance available as of October 8, 2026. It is not tax or legal advice for your specific business. Rates, rules and due dates can change. Confirm current guidance for your situation.
