CA — California

California Business Tax Extension — LLC & Partnership, S Corporation, C Corporation, Fiduciary

California grants every business entity an automatic, paperless extension. There is no California equivalent of federal Form 7004, and you do not need one — the FTB’s own instructions say in as many words that “California does not require filing written extensions.” You get the extra months without asking.

That automatic extension comes with two conditions that are easy to overlook because there is no form to remind you of them. First, the entity must not be suspended or forfeited as of the original due date — by the FTB or by the Secretary of State. Second, you must actually file by the extended due date. Miss either condition and the extension is void, not just late.

The length of that extension is not one number. A C corporation and an LLC or partnership each get seven months; an S corporation and a fiduciary each get six. And in every case, the extension buys you time to file — never time to pay. Whatever you owe is still due on the original March or April date.

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California Business Tax Extension — LLC & Partnership

California LLCs file Form 568 and partnerships file Form 565, both due the 15th day of the third month — Monday, March 16, 2026, since March 15 falls on a Sunday. The automatic extension runs a full seven months, to Thursday, October 15, 2026. That is a month later than the federal Form 1065 extension, and later than many filers expect: an S corporation extending from the same March date only reaches September.

Because the extension is automatic, no form is filed to claim it. A voucher is needed only if a payment is due and you are not paying electronically, and which voucher depends on entity type: LPs, LLPs, and REMICs use FTB 3538; a general partnership has no voucher at all, because it owes no entity-level tax to extend payment on. An LLC uses FTB 3537, but only if it owes nonresident members’ (NCNR) withholding tax — not for the $800 annual tax or the LLC fee, which have their own vouchers below.

This is where California’s LLC rules get genuinely confusing, because an LLC extending its 2025 return is carrying three separate obligations on three separate dates: the Form 568 return itself (extended to October 15), the $800 annual tax for 2026 (due April 15, 2026, on FTB 3522 — a prepayment for the year in progress, unrelated to the return being extended), and the estimated LLC fee for 2026 if California income will exceed $250,000 (due June 15, 2026, on FTB 3536). None of the three extends the others.

LLC & Partnership — 2026 Extension Checklist

One filing deadline in October — but two more payment dates in between.

California Late Filing & Late Payment Penalties — LLC & Partnership

The failure-to-file and failure-to-pay penalties each cap at 25%, but California adds a per-person penalty on top for partnerships, LLCs, and S corporations that the cap does not reach.

California LLC & Partnership — Quick Reference

California Business Tax Extension — S Corporation

California S corporations file Form 100S, due the same March 16, 2026 date as LLCs and partnerships — but the extension is six months, not seven, landing on Tuesday, September 15, 2026. Do not carry the LLC’s October date over to an S corporation; FTB 3539 itself prints “March 16, 2026” for this entity, which is the form’s own confirmation of the shifted start date.

Because a corporation and an S corporation share the automatic-extension conditions, the same trap applies: suspended or forfeited as of March 16, and the six months never existed. No extension form is filed either way; FTB 3539 is a payment voucher, used only if you owe money and are not paying electronically.

The $800 minimum franchise tax applies here at California’s S corporation rate of 1.5% of net income, or $800, whichever is greater — due whether the corporation is “active, inactive, operates at a loss, or files a return for a short period,” in the 100S booklet’s own words. A newly incorporated S corporation gets a first-year exemption from the $800 minimum (though not from tax on actual income); that exemption is unchanged and still applies to corporations in 2026.

S Corporation — 2026 Extension Checklist

Same March start date as an LLC. A different September finish.

California Late Filing & Late Payment Penalties — S Corporation

S corporations face the same failure-to-file and failure-to-pay caps as any other entity, plus the per-shareholder penalty most filers associate only with partnerships.

California S Corporation — Quick Reference

California Business Tax Extension — C Corporation

California C corporations file Form 100 (or Form 100W for water’s-edge filers) by Wednesday, April 15, 2026, and get the full seven-month automatic extension — to Monday, November 16, 2026, since November 15 is a Sunday. This is the same seven months as an LLC or partnership, just measured from April rather than March.

One FTB form sentence, read in isolation, says a corporation’s extension is six months. Three other current sources — the extension-to-file page, the business due-dates page, and the operative 2025 Form 100 booklet itself — all give seven, and the due-dates page ties the seventh month to a statutory change effective for tax years 2019 and later. November 16, 2026 is the date to file by.

The $800 minimum franchise tax applies at the regular corporate rate: 8.84% of net income, or $800, whichever is greater (10.84% for banks and financial corporations). It is due whether the corporation shows a profit, a loss, or files a short-period return, and a newly incorporated or newly qualified corporation is exempt from the $800 minimum — though not the income-based tax — in its first taxable year. A corporation that keeps transacting business after being suspended risks a separate $2,000-per-year penalty on top of everything else.

C Corporation — 2026 Extension Checklist

Pay in April. File as late as November.

California Late Filing & Late Payment Penalties — C Corporation

A C corporation does not face the per-shareholder penalty that hits partnerships, LLCs, and S corporations — but the mandatory e-pay penalty and the suspended-entity penalty are exposures unique to corporations.

California C Corporation — Quick Reference

California Business Tax Extension — Fiduciary / Estate / Trust

California estates and trusts file Form 541, due Wednesday, April 15, 2026. The automatic extension runs six months, to Thursday, October 15, 2026 — the same length as an S corporation, just starting a month later.

The extension voucher is FTB 3563, needed only if a payment is due and is not being paid electronically. Use it, or simply rely on the automatic extension and file Form 541 itself by October 15 — no separate request is required either way, subject to the same suspension condition as every other entity type.

Fiduciary returns carry a penalty the other three entity types do not: file more than 60 days late and the failure-to-file penalty becomes the greater of the standard 5%-per-month calculation or a flat minimum of the lesser of $135 or 100% of the tax due — the minimum is a floor under the ordinary penalty, not an amount added on top of it. A trust or estate that expects to owe little should not assume the exposure is small, since the $135 floor applies regardless of how modest the underlying tax is.

Fiduciary / Estate / Trust — 2026 Extension Checklist

Two dates, six months apart.

California Late Filing & Late Payment Penalties — Fiduciary / Estate / Trust

Fiduciary failure-to-pay works the same as any other entity, but failure-to-file does not simply stack a flat minimum on top — on a return filed more than 60 days late, the minimum replaces the percentage penalty whenever it would be larger.

California Fiduciary / Estate / Trust — Quick Reference

California Business Tax Extensions — Frequently Asked Questions

Ready to Extend Your California Business Return?

California’s extension is automatic once you qualify — but payment is still due on the original date. File your federal extension and cover both in one place.

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