California sales and use tax returns are filed through CDTFA Online Services, the California Department of Tax and Fee Administration's secure portal. This guide explains how to get into Online Services, what the return asks for, the due dates for each reporting basis, how prepayments work, and what happens if you file or pay late.
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: Sales and use tax return (Form CDTFA-401), filed online.
- Reporting basis: Monthly, quarterly, quarterly prepay, yearly, or fiscal yearly, assigned when you register.
- Due date: Generally the last day of the month after the period ends. Weekend and state holiday due dates move to the next business day.
- Zero returns: Required, even with no sales.
- Payment: Online through Online Services (ACH debit), credit card, EFT, or check.
Who has to file, and how often
Every seller's permit holder files a return for each assigned period. Remote sellers must register once their California sales of tangible personal property exceed $500,000 in the current or preceding calendar year. Our California sales tax guide covers registration and nexus.
When you register, CDTFA assigns you a reporting basis based on your expected or reported taxable sales:
| Reporting basis | How it works |
|---|---|
| Monthly | One return each month |
| Quarterly | One return for each calendar quarter |
| Quarterly prepay | Monthly prepayments during the quarter, plus a quarterly return |
| Yearly | One return for the calendar year |
| Fiscal yearly | One return for July through June |
CDTFA places businesses on quarterly prepay when their estimated taxable sales (the measure of tax) average $17,000 or more per month and CDTFA notifies them of the requirement. You can check your assigned basis in Online Services.
Before you start: set up Online Services
- Sign up for an Online Services profile. New users start at CDTFA's Sign Up Now link and create a username and password. You will need your account number to link your seller's permit.
- Have your numbers ready. You will need total sales for the period, purchases subject to use tax, your deductions by type, and a breakdown of sales by location or delivery destination for district tax.
Online Services also lets you make payments, request an extension or relief, manage more than one account under one login, and register new locations.
Step-by-step: filing a California sales and use tax return online
CDTFA describes the return by section. Online Services walks you through each one and calculates the tax from what you enter.
- Log in to Online Services and select the seller's permit account.
- Choose the return to file for the period that is due.
- Enter total sales. Report all taxable and nontaxable sales for the period, including lease and rental receipts.
- Enter purchases subject to use tax. This covers items bought from out-of-state retailers without California tax, or items bought with a resale certificate and then used in your business.
- Claim deductions. Common deductions include sales for resale to other retailers, nontaxable food products, nontaxable labor, sales to the U.S. government, sales in interstate or foreign commerce, and sales tax included in total sales.
- Complete Schedule A, district tax allocation. Allocate sales subject to district taxes, the voter-approved local taxes added to the 7.25% statewide base rate, to the districts where you operate or deliver.
- Complete any other schedules that apply. Businesses with more than one location report local tax by location, and some industries have their own schedules. Prior-period credits have a separate schedule.
- Review, pay, and submit. Online Services flags missing items, calculates the tax due, and lets you pay in the same session. Save the confirmation.
For eligible small businesses on a yearly or fiscal yearly basis, CDTFA added two tools in July 2026: Quick File, which checks eligibility with five questions and lets qualifying retailers file in a few minutes, and a guided Return Filing Tool. Both are available inside Online Services.
If you find a mistake in a past return, file an amended return for that period rather than adjusting the current one.
Due dates and the weekend rule
| Reporting basis | Period | Due date |
|---|---|---|
| Monthly | Each month | Last day of the following month |
| Quarterly | January–March | April 30 |
| Quarterly | April–June | July 31 |
| Quarterly | July–September | October 31 |
| Quarterly | October–December | January 31 |
| Quarterly prepay | Monthly prepayments | Generally the 24th of the following month (for example, January is due February 24) |
| Yearly | January–December | January 31 |
| Fiscal yearly | July–June | July 31 |
If a due date falls on a weekend or state holiday, it moves to the next business day. For example, the third-quarter 2026 return is due Monday, November 2, 2026, because October 31 is a Saturday.
Payment cutoffs: Online payments made on the due date must be completed before midnight Pacific time. EFT payments must be completed before 3 p.m. Pacific time on the due date.
Filing a zero return
You must file a return by the due date even if you had no sales. If you are a quarterly prepay filer and had no sales in a prepayment period, you do not need to make that prepayment; you indicate on the quarterly return that you had no sales to report.
Payment methods and EFT rules
You can pay by ACH debit through Online Services, by credit card (the processor charges a fee of about 2.3%), by EFT, or by check or money order.
EFT is mandatory when your average monthly sales and use tax payments over a 12-month period are $10,000 or more. If you are required to use EFT and pay another way, CDTFA can charge a 10% penalty on returns and a 6% penalty on prepayments.
Penalties and interest for late filing
- Late return or late payment: 10% of the tax due. If both happen for the same period, the combined penalty does not exceed 10%.
- Late prepayment: 6% if made after the prepayment due date but before the return due date, increased to 10% for negligence or intentional disregard.
- Interest: Charged for each month or fraction of a month the payment is late, starting the day after the due date.
CDTFA can grant relief from penalties in some cases, such as circumstances beyond your control, if you request it through Online Services.
Common mistakes to avoid
- Skipping Schedule A. District taxes are allocated by location or delivery destination, 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 monthly prepayments around the 24th, not just the quarterly return.
- Correcting past errors on the current return. Amend the period where the error happened.
- Paying EFT late in the day. EFT payments must finish by 3 p.m. Pacific on the due date.
- Skipping zero returns. A return is due for every period, sales or not.
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. Plans start from $75 per filing, with no per-state subscription.
Frequently asked questions
How do I file California sales tax online?
Log in to CDTFA Online Services, select your seller's permit account, choose the return for the period, and enter total sales, purchases subject to use tax, deductions, and your district tax allocation. Online Services calculates the tax, and you can pay in the same session.
When is California sales tax due?
For monthly and quarterly filers, the last day of the month after the period ends: April 30, July 31, October 31, and January 31 for quarterly filers. Weekend and state holiday due dates move to the next business day.
What is a quarterly prepay account?
An account that makes monthly prepayments during each quarter and then files a quarterly return. CDTFA assigns it, with notice, when your 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.
Who has to pay California sales tax by EFT?
Businesses whose average monthly sales and use tax payments over a 12-month period are $10,000 or more.
What are the penalties for filing late in California?
A 10% penalty on late returns or late payments, capped at 10% combined for the same period, plus interest for each month or part of a month the payment is late.
Sources
- CDTFA, Online Services — File a Return
- CDTFA, Online Filing Instructions — Sales and Use Tax Return
- CDTFA, Filing Dates for Sales and Use Tax Returns
- CDTFA, Filing and Payments — Tax Guide for New Permit and License Holders
- CDTFA, Electronic Funds Transfer FAQs
- CDTFA, Publication 75, Interest, Penalties, and Collection Cost Recovery Fee
- CDTFA, News release 26-05: new digital tools for small businesses
Look up the exact rate for any address with our US sales tax calculator.
