The California sales tax deadline for second-quarter returns is July 31. If your business holds a seller’s permit and files quarterly, your April through June return is due to the CDTFA by Friday. This checklist is for owners filing this week; it covers what to gather, what to reconcile, and the mistakes that trigger notices.
The California sales tax deadline for second-quarter returns is July 31, 2026, for businesses holding a seller's permit and filing quarterly. These businesses must submit their April through June return to the California Department of Tax and Fee Administration (CDTFA) by this date. Filing involves a checklist to gather and reconcile sales data, separate taxable from nontaxable sales, and verify district allocations, which helps prevent common errors that trigger notices or audits.
Filing dates come straight from the CDTFA’s schedule: quarterly returns are due the last day of the month following each quarter. For the full background on permits, district rates, and who must file, see our California sales tax guide. This post is the short version for deadline week.
The July 31 filing checklist
- Pull sales by channel for April 1 through June 30. POS reports, invoice totals, and online store payouts, separated, because marketplace sales are handled differently.
- Reconcile the total to your books. The revenue on the return should match the quarter’s revenue in QuickBooks or Xero. A mismatch here is the number one audit flag we see.
- Separate taxable from nontaxable sales. Resale-certificate sales, most services, and marketplace-facilitated sales get reported differently. Guessing creates either an overpayment or a notice.
- Check your district allocations. California layers district taxes on the statewide rate, and deliveries into other districts can owe those rates. This is where multi-city sellers slip.
- File and pay on the CDTFA portal, then save the confirmation. File the return even if you owe nothing; a zero return is still a required return.
California sales tax deadline dates for the rest of 2026
Mark the remaining dates now and the panic disappears:
| Period | Due date |
|---|---|
| Q2 (Apr-Jun) | July 31, 2026 |
| Q3 (Jul-Sep) | November 2, 2026 (Oct 31 falls on a weekend) |
| Q4 (Oct-Dec) | February 1, 2027 |
Larger accounts on a prepayment schedule also owe monthly prepayments, generally on the 24th, per the CDTFA calendar. If you are unsure which schedule you are on, your CDTFA account page says so at the top.
What common mistakes generate California sales tax notices?
- Reporting marketplace sales as your taxable sales. Amazon and similar marketplaces collect and remit for you; those sales are reported, but not taxed twice. Our ecommerce bookkeeping guide covers the split.
- Skipping the return in a slow quarter. Zero sales still means filing a zero return, on time.
- Paying from the wrong number. Filing from bank deposits instead of gross sales understates the return, because deposits arrive net of fees.
What should California sellers with mixed channels know about sales tax?
The messiest returns we see belong to businesses selling in person and online at once. A boutique with a register, a Shopify store, and an Amazon presence has three data sources, three fee structures, and two different sales tax treatments in a single quarter. The fix is structural, not heroic: each channel gets its own revenue account in the books, reconciled monthly against its own reports. Do that, and the quarterly return becomes addition. Skip it, and every deadline week starts with archaeology.
Also, watch the calendar note above about prepayment accounts. Once your volume crosses the CDTFA’s thresholds, they move you to monthly prepayments by notice, and missing the first one is a common surprise. The notice arrives by mail and in your CDTFA portal messages, so check both after any strong quarter.
How does Books LA assist with California sales tax filing?
For clients on our monthly service, the quarter’s sales are already reconciled by channel when the deadline arrives, so the return is a report, not a project. Sales tax is transactional compliance, squarely our lane. Details on our services page.
Frequently asked questions
What if I miss the July 31 deadline?
File as soon as possible. The CDTFA applies penalties and interest to late returns and payments, and they grow with time. If something genuinely prevented filing, the CDTFA has a relief-request process, but filing late beats not filing.
I had no sales this quarter. Do I still file?
Yes. An active seller’s permit means a return every period, even a zero one. Skipped zero returns are one of the most common ways small businesses end up with notices and estimated assessments.
Do I owe sales tax on my Amazon sales?
Generally no; registered marketplaces collect and remit California sales tax for you under the Marketplace Facilitator Act. You still report the figures per the return’s instructions. Direct website sales remain fully your responsibility.
How do I know if I should be filing monthly, quarterly, or annually?
The CDTFA assigns your schedule based on sales volume, and it is shown in your online account. They also move businesses between schedules as volume changes, by notice. Check the account rather than assuming last year’s schedule still applies.
What is a district tax and why does my rate vary?
California’s statewide rate is the floor; cities and counties add voter-approved district taxes on top. Your rate depends on where the sale or delivery happens, which is why deliveries across the region can carry different rates. The CDTFA’s rate lookup by address settles any doubt.
Can my bookkeeper file this for me?
Yes, and for our clients we prepare the numbers as part of the monthly close so filing takes minutes. What matters is that the return ties to the books; whoever files should be working from reconciled records, not raw bank deposits.
If quarterly filings keep turning into fire drills, book a short call with Books LA and we will put them on rails.
This article is general information, not tax advice. Books LA provides bookkeeping services, including sales tax support, and does not provide income tax advice; we work with our clients’ CPAs on income tax matters. Confirm your filing schedule and rates with the CDTFA.
