Deadlines
The dates that cost money if you miss them
Federal and California, from now through the end of 2027. An extension extends the time to file and never the time to pay — tax owed is still due on the original date, and interest runs from there.
Read this first
Dates that fall on a Saturday, Sunday or legal holiday move to the next business day, and the IRS and the FTB sometimes postpone dates after a declared disaster. This page is a general guide, not tax advice — always confirm the dates that apply to you against irs.gov and ftb.ca.gov, or ask us.
01Federal
The filing cycle, date by date
| Date | What is due |
|---|---|
| Extended 2025 partnership (Form 1065) and S-corporation (Form 1120-S) returns are due. Third-quarter 2026 estimated tax payment for individuals. | |
| Extended 2025 individual returns (Form 1040) and extended 2025 C-corporation returns (Form 1120) are due. This is the final deadline — there is no further extension. | |
| Fourth-quarter 2026 estimated tax payment for individuals. Paying by this date stops further underpayment interest accruing on the 2026 year. | |
| Forms W-2 to employees and 1099-NEC to contractors, and the same forms filed with the SSA and the IRS. Both the recipient copy and the agency copy are due on this date. | |
| 2026 partnership (Form 1065) and S-corporation (Form 1120-S) returns, with Schedule K-1 to every owner — or Form 7004 for a six-month extension. Also the deadline to elect S-corporation status for 2027 on Form 2553. | |
| 2026 individual returns (Form 1040) and C-corporation returns (Form 1120), or an extension. First-quarter 2027 estimated payment. Last day to make a 2026 IRA contribution. | |
| Second-quarter 2027 estimated tax payment for individuals. | |
| Extended 2026 partnership and S-corporation returns are due. Third-quarter 2027 estimated tax payment. | |
| Extended 2026 individual and C-corporation returns are due. Final deadline for the 2026 year. |
02California
The California-only dates
These are the ones that catch people out, because a federal calendar does not contain them and nobody sends a reminder.
| When | What is due |
|---|---|
| 15 April, every year | California $800 minimum franchise tax or annual LLC tax, for the current tax year — not the year you are filing for. LLCs pay it on Form 3522. It is owed whether or not the business made any money. |
| 15 June, every year | Estimated LLC fee on Form 3536, for LLCs whose California total income is expected to reach the fee thresholds. Underpaying it carries a penalty, so it is estimated from real figures rather than guessed. |
| 30 April, 31 July, 31 October, 31 January | Quarterly payroll returns with the EDD — Form DE 9 and DE 9C — due at the end of the month following each quarter. Federal Form 941 is due on the same dates. |
| Annually or every two years | Statement of Information with the California Secretary of State — annually for corporations, every two years for LLCs, in the filing window tied to your registration month. Filed through bizfile. |
| 4½ months after fiscal year end | Form RRF-1 with the California Registry of Charities and Fundraisers, for registered charitable organisations — 15 May for a calendar-year charity. The federal Form 990 series is due on the same schedule. |
03If a date has passed
A missed deadline is fixable
- File as soon as you can. The failure-to-file penalty runs far faster than the failure-to-pay penalty, so filing without full payment beats not filing.
- Pay what you can on the day you file. Interest is charged only on the unpaid balance.
- Ask about first-time penalty abatement. A clean compliance history often qualifies for relief, and it has to be requested.
- Send us any notice before you respond to it. A wrong reply is harder to undo than a late one.
Dates that fall on a Saturday, Sunday or legal holiday move to the next business day, and the IRS and the FTB sometimes postpone dates after a declared disaster. This page is a general guide, not tax advice — always confirm the dates that apply to you against irs.gov and ftb.ca.gov, or ask us.
Let’s find out what you should actually be paying.
Thirty minutes with an Enrolled Agent, at no charge. Bring last year’s return and we will tell you plainly what we would do differently — and what it would cost.