To file sales tax in California online, log into the California Department of Tax and Fee Administration (CDTFA) online services portal, open the reporting period for your seller’s permit account, enter your gross sales and deductions, let the system apply the right district tax rates, submit the return, and pay the balance. The statewide base rate is 7.25%, and combined district rates can reach 11.25% depending on where the sale takes place. You must file for every assigned reporting period, even a period with zero sales.
What You Need Before You Log In
You need an active seller’s permit. The permit itself is free, though the CDTFA may require a security deposit at registration to cover potential unpaid taxes if the business later closes.1California Department of Tax and Fee Administration. Obtaining a Seller’s Permit Registration happens on the CDTFA website. Out-of-state sellers who exceed $500,000 in sales delivered into California during the current or prior calendar year must register for a Certificate of Registration to collect use tax, even without a physical presence in the state.2California Department of Tax and Fee Administration. Use Tax Collection Requirements Based on Sales into California
You also need clean numbers for the period. The main figure is total gross sales, covering every transaction whether taxable or exempt. From that, you subtract deductions such as sales for resale, sales in interstate commerce, and sales to the federal government. What is left is your taxable measure. Track any purchases your business made from out-of-state vendors who did not charge California tax; those get reported separately as purchases subject to use tax.
Every figure on the return should be backed by invoices, receipts, shipping records, and bank statements. CDTFA Regulation 1698 requires you to keep these records for at least four years.3California Department of Tax and Fee Administration. Regulation 1698 – Records If an audit comes and you cannot produce documentation, the CDTFA can estimate your liability, which rarely favors the business.
For any resale deduction, keep a completed resale certificate from the buyer on file, and confirm that the buyer’s seller’s permit number is valid. A California resale certificate does not expire while the buyer’s permit stays active. If the CDTFA later finds the buyer was not actually purchasing for resale, you can still be held responsible for the uncollected tax unless you accepted the certificate in good faith.
Filing the Return in the CDTFA Portal
Sign in to the CDTFA online services portal with your username and password, open your seller’s permit account, and select the reporting period you need to file.4California Department of Tax and Fee Administration. Online Filing Instructions – Sales and Use Tax Return The return moves through a series of screens.
Enter your total gross sales first. If you are on a quarterly schedule, enter the full amount for all three months, including any figures already covered by prepayments. The next screens ask for nontaxable deductions: labor charges, sales for resale, exempt food products, sales to the federal government, and other categories that apply to your business. Each entry reduces the taxable measure. After deductions, report any purchases subject to use tax.
The system applies district tax rates based on where your sales occurred, so a business with multiple locations or that delivers into different jurisdictions will see several rate calculations on a single return. The CDTFA publishes an address-based lookup to confirm the right rate for any location.5California Department of Tax and Fee Administration. Find a Sales and Use Tax Rate The portal handles the arithmetic once your figures are in, which removes most calculation errors. Before you submit, compare the summary page line by line against your own bookkeeping.
When you submit, the system generates a confirmation number with a timestamp. Save or print that page. It is your proof of timely filing.
Paying What You Owe
Filing does not complete the obligation. You also have to pay. The CDTFA offers several options:
- ACH debit through Express Check, which pulls funds directly from your bank account at no extra cost.
- Credit card, processed through a third-party vendor that charges a 2.3% service fee on top of the tax. The CDTFA does not receive any part of that fee.6California Department of Tax and Fee Administration. Credit Card Payment Information
- Check by mail, sent with a payment voucher printed from the portal. Allow time for the payment to arrive before the deadline.
A return submitted without payment is not considered complete. Interest and late-payment penalties start accruing on any unpaid balance after the due date.
If your average monthly sales tax liability reaches $17,000 or more, the CDTFA notifies you that prepayments are required during the reporting period, on top of your regular return.7California Department of Tax and Fee Administration. California Revenue and Taxation Code 6471 – Prepayment Missing a prepayment deadline carries its own penalties.
When Your Return Is Due
The CDTFA assigns your filing frequency, typically monthly, quarterly, or annually, based on expected sales volume at the time your permit is issued. The general rule is that the return and payment are due by the last day of the month after the reporting period ends.8California Department of Tax and Fee Administration. California Revenue and Taxation Code 6451 – Due Date
For quarterly filers:
- January through March, due April 30.
- April through June, due July 31.
- July through September, due October 31.
- October through December, due January 31.
Monthly filers follow the same pattern one month at a time; a June return is due July 31. Annual filers covering January through December must file by January 31 of the following year.9California Department of Tax and Fee Administration. Filing Dates for Sales and Use Tax Returns If a due date lands on a weekend or state holiday, the deadline moves to the next business day.
You still have to file even if you had no sales for the period.9California Department of Tax and Fee Administration. Filing Dates for Sales and Use Tax Returns Skipping a zero-sales filing is one of the more common mistakes new businesses make, and it triggers the same penalties as any other late return.
Fixing a Return You Already Filed
If you spot an error after submitting, you can amend through the same portal. Log in, open the account and reporting period, select the option to amend, enter the corrected numbers, and submit.10California Department of Tax and Fee Administration. Amend a Return If the correction increases your tax, pay the additional amount with any penalty and interest that applies. If it decreases your tax, the CDTFA treats the amended return as a refund claim automatically, so no separate filing is needed. Electronic amendments are typically processed overnight.
If You File or Pay Late
Late filing and late payment each carry a 10% penalty. If both happen on the same return, the combined penalty is capped at 10% of the tax due for that period, not 20%.11California Department of Tax and Fee Administration. Having Trouble Paying Taxes Interest also accrues on any unpaid balance. For 2026, the CDTFA charges 10% annual interest on deficiencies, calculated by adding 3 percentage points to the IRS rate.12California Department of Tax and Fee Administration. Interest Rates
If you cannot pay the full balance, the CDTFA offers payment plans. You can apply online if all required returns have been filed and you have a past-due balance. Monthly payments must be at least $10, and you propose the amount.13California Department of Tax and Fee Administration. Online Services – Payment Plan Interest continues to accrue on the remaining balance. Accounts in bankruptcy, probate, or receivership cannot apply online and must contact the CDTFA directly.
If the lateness was caused by circumstances truly outside your control, you can request penalty relief from the CDTFA.14California Department of Tax and Fee Administration. Relief Request Help These requests are decided case by case. A portal outage on the night of the deadline is the kind of thing that can qualify. Forgetting the date is not.
If You Sell Only Through a Marketplace
If a platform like Amazon, eBay, or Etsy handles your sales, the marketplace facilitator is responsible for collecting and remitting California sales tax on those transactions.15California Department of Tax and Fee Administration. Tax Guide for Marketplace Facilitator Act If every one of your sales runs through such a marketplace, you generally do not need a seller’s permit at all.
Marketplace-facilitated sales still count toward the $500,000 economic nexus threshold. Once total California sales across all channels reach that number, you must register with the CDTFA and file returns for any direct sales you make outside the marketplace. The marketplace handles tax on the sales it facilitates; anything you sell directly to California customers stays your responsibility.