How to File California Sales Tax Online in 2026

California sales and use tax is filed in CDTFA Online Services, the California Department of Tax and Fee Administration's portal, on the State, Local, and District Sales and Use Tax Return (CDTFA-401-A). Monthly returns are due on the last day of the month after the period ends, quarterly returns on April 30, July 31, October 31, and January 31, and a return is required every period, even with no sales.

This guide covers who files and how often, how to file in Online Services, how California's district taxes and local allocation work, how prepayments and zero returns are handled, how to amend a return, how to pay, and what late filing costs.

This article is educational information, not tax advice. Filing rules, thresholds, and penalties can change, so confirm current requirements with the CDTFA before you file.

California sales tax filing at a glance

• Who administers it: California Department of Tax and Fee Administration (CDTFA).
• Online portal: CDTFA Online Services at onlineservices.cdtfa.ca.gov.
• Return: State, Local, and District Sales and Use Tax Return (CDTFA-401-A), filed online.
• Filing frequency: Monthly, quarterly, quarterly prepay, yearly, or fiscal yearly, assigned by CDTFA when you register.
• Due dates: Generally the last day of the month after the period ends. Quarterly prepay filers also owe prepayments by the 24th. A due date on a weekend or state holiday moves to the next business day.
• Zero returns: Required for every period, even with no sales.
• Payment: ACH debit through Online Services, credit card, EFT, or check or money order. EFT is required when average monthly sales and use tax liability is $10,000 or more over 12 months.
• Economic nexus: Retailers outside California must register and collect use tax when combined sales of tangible personal property for delivery in California, with related persons, exceed $500,000 in the preceding or current calendar year.

Who has to file, and how often

If you hold a seller's permit, you file a return and pay any tax due for each period CDTFA assigns. Out-of-state retailers must register with CDTFA and collect California use tax once their combined sales of tangible personal property for delivery in California, together with sales by related persons, exceed $500,000 in the preceding or current calendar year. Retailers with a physical presence in California, such as inventory, an office, or representatives taking orders or making deliveries, must generally register regardless of that threshold. Our California sales tax guide covers registration and nexus in more detail. Selling software? SaaS becomes taxable on January 1, 2027, and our post on California SaaS sales tax explains the new rules.

When you register, CDTFA assigns a reporting basis from the sales tax you report or the taxable sales you expect:

CDTFA places a business on quarterly prepay when its estimated taxable sales (the measure of tax) average $17,000 or more per month and CDTFA notifies it of the requirement. If you do not know your reporting basis, CDTFA says to call its Customer Service Center at 1-800-400-7115.

Before you start: get into Online Services

You need a California seller's permit or other CDTFA account before you can file. If you have not registered yet, see how to get a seller's permit in California and our overview of the sales tax permit process.

To use Online Services, use CDTFA's Sign Up Now link and create a username and password. Depending on your account type and access level, the profile lets you file and view returns, make payments, request an extension or relief, manage more than one account under one login, and register a new location. To receive filing reminders by email, update your email address in your online profile.

Before filing, gather your CDTFA account number, sales, purchases, and deductions for the period, and payment information. For district tax you also need to know where you are engaged in business and where you deliver.

Step-by-step: filing a California sales and use tax return online

CDTFA describes the return by section, and Online Services calculates the tax from what you enter.

1. Log in to Online Services and select the account.
2. Choose the return for the period that is due.
3. Enter total sales. Report all taxable and nontaxable sales for the period, including lease and rental receipts, labor, service, and shipping and handling charges. Quarterly prepay filers enter sales for all three months, even after making prepayments.
4. Enter purchases subject to use tax. This covers property bought from an out-of-state retailer that did not collect California use tax, or bought with a resale or other exemption certificate and then used in California for something other than resale.
5. Claim deductions. The return lists sales to other retailers for resale (see the California resale certificate rules), nontaxable food products, nontaxable labor, sales to the U.S. government, sales in interstate or foreign commerce, and sales tax included in total sales. If your total sales include California sales tax, deduct it here or you will overpay.
6. Complete Schedule A, district tax allocation. Report sales and purchases subject to district tax and allocate them to the districts where you are engaged in business. Sales subject only to the state rate go in a separate field.
7. Complete the other schedules that apply. Schedule B allocates certain transactions by county, Schedule C allocates local tax to your registered California locations, and Schedule Q claims credits from prior periods such as bad debts and returned merchandise.
8. Review, pay, and submit. Online Services calculates the tax due and lets you pay in the same session. Save the confirmation.

For eligible small businesses, CDTFA added two tools in July 2026 for retailers who file online: Quick File, which checks eligibility with five questions and lets qualifying retailers complete a fiscal-yearly or annual return in under two minutes, and a guided Return Filing Tool. Both are reached by logging in to Online Services.

District taxes and local rate pitfalls

California's statewide base rate is 7.25%, which includes 1.25% of local tax (a 1% local jurisdiction share and a 0.25% local transportation share). Most local jurisdictions have added voter-approved district taxes on top, and more than one district tax can apply in the same place. Neither piece is a single rate you can apply to every sale.

• District tax follows where you are engaged in business. CDTFA says you generally collect, report, and pay the district rate if you have a business location in the district, have representatives making sales or deliveries there, lease property there, own or lease property there (including a computer server), deliver into the district with your own vehicle, or meet the $500,000 threshold that triggers district use tax collection. Sales delivered to a district where you are not engaged in business are reported at the state rate only.
• Local tax is allocated by place of sale. Schedule C allocates to your registered California selling locations, and Schedule B covers transactions such as shipments from out of state with title passing outside California and itinerant or vending sales. CDTFA points to Regulation 1802 on place of sale.
• Vehicles, vessels, and aircraft differ. Registered sellers generally apply the rate where the customer registers the item.
• A ZIP code is not enough. CDTFA says the correct rate cannot always be determined from a mailing address or ZIP code, and offers a rate lookup by address and a city and county rate list.
• Rates change. District rates generally take effect on the first day of the next calendar quarter, at least 110 days after adoption, and CDTFA announces changes in special notices.
• Excess tax is not yours to keep. If you collect more than is due, you must return it to the customer or pay it to the state.

Our California sales tax calculator shows the combined rate for a location.

Due dates and the weekend rule

For quarterly prepay filers in the second quarter, the second prepayment covers May 1 through June 15 and is due June 24. Quarterly prepay filers then file the quarterly return by the dates above. Our California sales tax due dates page lists upcoming dates for every state.

If a due date falls on a weekend or state holiday, it moves to the next business day. For example, October 31, 2026 is a Saturday, so the third-quarter 2026 return is due Monday, November 2, 2026.

Payment cutoffs: A payment made online on the due date must be completed before midnight Pacific time. For accounts that pay by EFT, a payment made through Online Services on the due date must be completed by 3 p.m. Pacific time so the funds settle by the first banking day after the due date.

Filing a zero return

A return is required on or before the due date even if there are no sales to report, and CDTFA says it is not necessary to submit a zero payment when no tax is due. CDTFA's EFT FAQ says you simply enter zero for the sales and transaction amounts.

If you are on quarterly prepay and made no sales in a prepayment period, you do not need to make that prepayment. CDTFA's filing instructions say to indicate on your quarterly return that you had no sales to report for that period, and its prepayment page notes it may ask why no taxable transactions occurred.

Amending a return

If you find an error on a return you already filed, CDTFA says to file an amended return and pay any additional tax due, including penalty and interest. Do not adjust the current period's sales for a prior-period error. To amend electronically:

1. Log in to Online Services and, on the Accounts tab, select the account.
2. On the Recent Periods tab, select the period to amend.
3. Under I Want To, choose File, Amend, or Print a Return/Report, then Amend Return.
4. Enter your corrected figures and follow the prompts to submit.

CDTFA applies payments made with the original return to the amended one, and penalty and interest adjust automatically once it is processed, generally overnight. An amended return that results in a refund is treated as a claim for refund, so no separate claim is needed. For a period not available electronically, CDTFA says to mail a marked copy of the original return with a cover letter.

Payment methods and EFT rules

You can pay by:

• ACH debit: Authorize CDTFA to transfer funds from your bank account through Online Services. CDTFA says there is no cost for using Online Services for this, though your bank may charge a fee for the transfer.
• Credit card: American Express, Discover, MasterCard, and Visa are accepted, with a 2.3% service fee charged by the card processor and retained by the vendor.
• EFT: ACH debit or ACH credit, with the cutoffs above.
• Check or money order: Payable to the California Department of Tax and Fee Administration.

EFT is required by law if your average monthly sales and use tax liability is $10,000 or more over a 12-month period. If you must pay by EFT and pay another way, including by credit or debit card, CDTFA assesses a 10% penalty on returns and a 6% penalty on prepayments. Quarterly prepay accounts satisfy the prepayment requirement with an electronic payment; paper prepayment forms are no longer provided.

If you are on quarterly prepay, each of the first two monthly prepayments must be at least 90% of the state and local tax liability for the period. CDTFA's example is a January liability of $30,000, which means a prepayment of at least $27,000 by February 24. The second-quarter prepayment covering May 1 through June 15 can instead be 135% of May's liability.

Penalties and interest for late filing

• Late return or late payment: 10% of the tax due for each. If both apply to the same period, the total penalty does not exceed 10%.
• Late prepayment: 6% if made after the prepayment due date but before the return due date. CDTFA can increase it to 10% for negligence or intentional disregard.
• Interest: Charged for each month or fraction of a month the tax is late, starting the day after the due date. The rate is set by CDTFA based on the IRS rate plus three percent and reviewed each January and July, so check CDTFA's interest rates page for the current figure.
• Failure to file: If CDTFA determines you should have filed and did not, it bills you for the tax with interest and penalty.

Illustration only: using the stated 10% cap, a return with $2,500 of tax due that is filed late and paid late carries a penalty of at most $250, not $500. Interest is charged in addition.

CDTFA can grant relief from penalty in limited cases, such as a disaster or circumstances beyond your control, and can grant extensions of time to file or pay. Interest can be waived only in limited cases such as a disaster. You can request relief or an extension in Online Services. For how other states compare, see our sales tax filing penalties and discounts by state guide.

Common California sales tax filing mistakes

• Skipping Schedule A. District taxes are allocated to the districts where you are engaged in business, not reported as one lump sum.
• Leaving out purchases subject to use tax. Untaxed out-of-state purchases and resale-certificate purchases used in the business belong on the return.
• Missing prepayments. Quarterly prepay filers owe prepayments by the 24th of each of the first two months of the quarter, not just the quarterly return.
• Correcting past errors on the current return. Amend the period where the error happened.
• Leaving sales tax in total sales. If total sales include California sales tax, deduct it on the sales tax included line or you overpay.
• Paying an EFT account by card or check. It triggers the EFT penalty, and Online Services EFT payments made on the due date must be completed by 3 p.m. Pacific.
• Skipping zero returns. A return is due for every period, sales or not.

If you receive a sales tax notice

A missed or late return often leads to a letter. Our California sales tax notices guide explains the notices the California Department of Tax and Fee Administration sends, including Notice of Delinquency, Demand for Immediate Payment, and Notice of Determination. It also covers how to ask for penalty relief: Request for Relief from Penalty, Collection Cost Recovery Fee, and/or Interest (CDTFA-735). Check the date on the notice, match it to your filing period, and follow the instructions on the notice itself.

Next steps for California sellers

• Download California's due dates as a calendar file, or see them on the due dates page.
• Check the combined rate for any California address.
• Get the California resale certificate to buy inventory without paying tax.
• Check whether you have nexus in other states before your sales cross a threshold.

More state filing guides

Filing in more than one state? These step-by-step guides cover the portals, due dates, and penalties in other states. See them all in our state-by-state guide to filing sales tax online.

• How to file Hawaii sales tax online
• How to file Washington sales tax online
• How to file Arizona sales tax online

Let Kintsugi file for you

If allocating district tax and tracking prepayments takes more time than it should, Kintsugi's sales tax filing software prepares and files California returns on your assigned basis, including zero returns, and remits payment. Monitoring across every US state is free, so you know when you cross a threshold. Filing starts at $75 per filing, with no per-state subscription. See pricing, start free, or book a demo.

Frequently asked questions

How do I file California sales tax online?

Log in to CDTFA Online Services, select your account, choose the return for the period, and enter total sales, purchases subject to use tax, deductions, and your district tax allocation on Schedule A. Online Services calculates the tax, and you can pay in the same session.

How do I log in, and does it cost anything to file?

Create a username and password through CDTFA's Sign Up Now link, then log in to Online Services. CDTFA says there is no cost for using Online Services to make ACH debit payments, though your bank may charge a transfer fee. Credit card payments carry a 2.3% fee charged by the card processor.

When is California sales tax due?

For monthly filers, the last day of the month after the period ends. For quarterly filers, April 30, July 31, October 31, and January 31. Weekend and state holiday due dates move to the next business day.

What is a quarterly prepay account?

An account that makes prepayments for the first two months of each quarter and then files a quarterly return. CDTFA assigns it, with notice, when estimated taxable sales average $17,000 or more per month.

Do I have to file if I had no sales?

Yes. You must file by the due date even with no sales to report.

Can I pay California sales tax by credit card?

Yes, unless your account is required to pay by EFT, in which case a card payment triggers a penalty. The card processor charges a 2.3% service fee.

How do I amend a California sales tax return?

In Online Services, open the account, select the period on the Recent Periods tab, and choose Amend Return. Payments made with the original return are applied to the amended one, and an amended return that results in a refund is treated as a claim for refund.

Who has to pay California sales tax by EFT?

Businesses whose average monthly sales and use tax liability is $10,000 or more over a 12-month period.

What are the penalties for filing late in California?

A 10% penalty on a late return or a late payment, capped at 10% combined for the same period, plus interest for each month or part of a month the payment is late. Late prepayments carry a 6% penalty.

Is there a discount for filing California sales tax on time?

The agency pages and return instructions we reviewed describe no timely-filing discount or collection allowance for California sales tax. Confirm with the California Department of Tax and Fee Administration if you think one applies to your account.

Sources

Checked September 29, 2026.

• CDTFA, Online Services: File a Return
• CDTFA, Online Services overview
• CDTFA, Online Filing Instructions: Sales and Use Tax Return
• CDTFA, Filing Dates for Sales and Use Tax Returns
• CDTFA, Return Prepayments
• CDTFA, Filing and Payments: Tax Guide for New Permit and License Holders
• CDTFA, Amend a Return
• CDTFA, Electronic Funds Transfer FAQs
• CDTFA, Publication 75: When Do Interest, Penalty, and the Collection Cost Recovery Fee Charges Apply
• CDTFA, Publication 75: Relief From Interest, Penalty, and the Collection Cost Recovery Fee
• CDTFA, Know Your Sales and Use Tax Rate
• CDTFA, Use Tax Collection Requirements Based on Sales into California (Wayfair)
• CDTFA, Publication 105: District Taxes and Sales Delivered in California
• CDTFA, News release 26-05: new digital tools for small businesses