Every October, somebody calls a CPA on the 14th. The return has been on extension since April, the books are eleven months behind, and there’s exactly one day left. It usually works out. It’s never pleasant, and it’s always more expensive than it needed to be.
This guide exists so that call isn’t you. Below is every 2026 federal deadline that matters to small businesses, freelancers, and individual filers, grouped the way liabilities actually work: income tax, estimated payments, payroll, and information returns. We checked each date against IRS Publication 509, the IRS’s official tax calendar for 2026, and the dates already account for weekends and holidays. That’s why some deadlines you’d expect on the 15th or the 31st fall on the 16th or the 2nd instead.
The short version: September 15 is the third estimated-tax installment and the deadline for extended partnership and S corporation returns. October 15 is the last stop for extended individual and C corporation returns. December 15 closes out corporate estimates for the year, and individuals make their final 2026 estimated payment on January 15, 2027.
The deadlines still ahead in 2026
We’re past the middle of the year, so start with what’s actually coming. If any of these apply to you, they belong in your calendar today, not in a browser tab you’ll lose.
| Date | Who | What’s due |
|---|---|---|
| July 31, 2026 | Employers | Form 941 for Q2; deposit FUTA tax owed through June if over $500; Form 5500 for employee benefit plans |
| September 15, 2026 | Individuals & self-employed | Third installment of 2026 estimated tax |
| September 15, 2026 | Partnerships & S corporations | Extended 2025 returns (Forms 1065 and 1120-S), with Schedules K-1 to owners |
| September 15, 2026 | C corporations | Third installment of 2026 estimated tax |
| October 15, 2026 | Individuals | Extended 2025 Form 1040. The final deadline if you filed Form 4868 in April |
| October 15, 2026 | C corporations | Extended 2025 Form 1120 |
| November 2, 2026 | Employers | Form 941 for Q3; FUTA deposit if over $500 |
| December 15, 2026 | C corporations | Fourth installment of 2026 estimated tax |
| January 15, 2027 | Individuals & self-employed | Fourth and final installment of 2026 estimated tax |
A word to anyone on extension who hasn’t started yet. The extension moved your filing date, not your payment date, so interest has been running on any unpaid 2025 balance since April. And if the real holdup is that the books aren’t done, that’s a bookkeeping problem wearing a tax-deadline costume. It’s fixable in the time you have left. It is not fixable in the last week of it.
Federal income tax deadlines, by filer type
“When are taxes due” has three different answers depending on what you file. Here they are separately, because mixing them up is exactly how new S corporation owners end up a month late without knowing it.
Individuals and sole proprietors
Form 1040 was due April 15, 2026 — and if you freelance, your Schedule C rides along with it, so there is no separate “business return” to file. Americans living abroad on the due date got an automatic two months, to June 15. If you filed Form 4868, your extended deadline is October 15, 2026, and there is no extension of the extension.
Partnerships and S corporations
Forms 1065 and 1120-S were due March 16, 2026, a full month before individual returns. That’s not the IRS being difficult; the K-1s from these returns have to reach the owners in time for them to file their own 1040s. On extension, both come due September 15, 2026. March 16 was also the Form 2553 deadline to elect S corporation status for 2026 — miss it and the election generally waits until 2027, though late-election relief exists for some situations. Whether you qualify is a question for a U.S. licensed CPA, not a forum thread.
C corporations
Form 1120 was due April 15, 2026, with the extended deadline on October 15. Corporations also pay estimated tax in four installments: April 15, June 15, September 15, and December 15.
Estimated taxes: the deadline freelancers miss most
Nobody withholds taxes from a freelancer’s invoices. The IRS knows this, so it asks for the money quarterly instead, through estimated payments on Form 1040-ES:
- April 15, 2026 — first installment (passed)
- June 15, 2026 — second installment (passed)
- September 15, 2026 — third installment
- January 15, 2027 — fourth installment
If you skipped April and June, don’t wait until next spring to deal with it. The penalty accrues per installment, per day, so catching up in September stops the meter on two quarters at once. A tax preparer can tell you exactly where you stand and size the remaining payments so April 2027 holds no surprises.
This is also where a bookkeeper quietly earns their fee. You can’t pay accurate quarterlies from numbers you don’t have. And if the problem isn’t knowing the number but actually having the cash on the date, that’s the conversation a fractional CFO exists for.
Payroll and employer filing deadlines
The moment you hire your first employee, you inherit a second tax calendar that runs all year whether you think about it or not.
Form 941, quarterly. Due one month after each quarter closes: February 2 (Q4 2025), April 30, July 31, and November 2, 2026. The Q4 2026 filing lands at the start of February 2027.
Form 940, annually. The FUTA return for 2025 was due February 2, 2026, but the tax itself deposits during the year — any quarter your FUTA liability passes $500, deposit by the end of the following month.
Forms W-2. To employees and to the SSA with Form W-3 by February 2, 2026 for the 2025 year. One date, both copies.
Household employers. Paid a nanny or caregiver $2,800 or more in cash wages in 2025? Schedule H files with your April 15 Form 1040.
One distinction that catches new employers: the filing dates above don’t control your deposit dates. Payroll tax deposits run on their own monthly or semiweekly schedule under Publication 15, and missing a deposit carries its own penalty even if the quarterly return is filed on time. If the word “semiweekly” just raised your blood pressure, that’s a sign the payroll calendar belongs with your bookkeeping and payroll support, not on a sticky note.
Information returns: 1099s and W-2s
These are the forms with the least tax on them and the most predictable penalties, because they’re charged per form and step up the longer you wait.
Form 1099-NEC — for contractors you paid $600 or more — was due February 2, 2026, both to the IRS and to the contractor, with no later e-file date. This is the one small businesses miss most.
Most other 1099s (interest, rents, royalties, and the rest) went to recipients by February 2, with Forms 1099-B and 1099-S allowed until February 17. Copies to the IRS were due March 2 on paper or March 31 electronically.
Missed one? File it the day you notice. The penalty tiers reward speed and punish waiting, so a 1099 filed a month late costs a fraction of one filed after August.
The full 2026 calendar at a glance
For late filers, amended returns, penalty math, and planning next year, here’s the whole year in one place. Same source, same weekend adjustments.
| Date | Deadline |
|---|---|
| January 15 | Final 2025 estimated tax installment (individuals) |
| February 2 | Form 1099-NEC filed and furnished; Forms W-2 to employees and the SSA with Form W-3; Form 941 (Q4 2025); Form 940 (FUTA); most other 1099 statements to recipients |
| February 17 | Forms 1099-B and 1099-S to recipients; new Form W-4 to continue a withholding exemption |
| March 2 | Paper filing of most information returns with the IRS (Form 1096) |
| March 16 | Partnership returns (Form 1065) with K-1s; S corporation returns (Form 1120-S); Form 2553 S corporation election for 2026; Form 7004 extensions |
| March 31 | Electronic filing of most information returns |
| April 15 | Form 1040 and payment; first 2026 estimated installment; Form 1120 and first corporate installment; household employer Schedule H; Form 4868 extensions |
| April 30 | Form 941 (Q1 2026) |
| June 15 | Second estimated installment; Form 1040 for Americans living abroad |
| July 31 | Form 941 (Q2); FUTA deposit; Form 5500 |
| September 15 | Third estimated installment; extended 1065 and 1120-S; third corporate installment |
| October 15 | Extended Form 1040; extended Form 1120 |
| November 2 | Form 941 (Q3); FUTA deposit |
| December 15 | Fourth corporate estimated installment |
What missing a deadline actually costs
The IRS penalizes not filing about ten times harder than not paying:
- Failure to file: generally 5% of the unpaid tax per month or part of a month, up to 25%.
- Failure to pay: 0.5% per month.
- Information returns like 1099s and W-2s: penalties run per form and step up the longer you wait.
If you take one thing from this article, take this: file on time even when you can’t pay. Owing the IRS money is a solvable problem with payment plans and known interest rates. Not filing is just an expensive silence.
Searching for a “tax consultant near me”? Read this first
Type “tax consultant near me” into Google and you’ll get whoever bought ads in your zip code this month. What you actually want is someone licensed, verifiable, and willing to sign your return. None of that depends on the address.
We run a remote-first practice, and our clients are spread across the country. Documents move through an encrypted client portal instead of email, meetings happen on video, and the credentials are the same ones the office downtown holds: a state CPA license you can verify online before paying us a dollar, and a PTIN on every return we sign. So skip “who’s closest” and ask the better question: who puts their license number on my return? If you’d like our answer to that, the consultation is free.
How to never miss a tax deadline again
- Put every date above that applies to you into your calendar now, with a reminder two weeks out. The IRS also publishes this calendar at IRS.gov/TaxCalendar if you want to subscribe.
- Close your books monthly. Every deadline on this page is easy when the numbers are reconciled and miserable when they aren’t.
- Pay electronically, through EFTPS, IRS Direct Pay, or your IRS online account, so every payment is timestamped instead of trusted to the mail.
- Decide on extensions in March, not on April 14. An extension is a planning tool. It never extends the payment date.
- Hand the calendar to a professional. The real value of a tax preparer isn’t filling in forms; it’s that deadlines, estimates, and elections stop being your job to remember.
Frequently asked questions
When is the tax extension deadline in 2026?
October 15, 2026 for individuals who filed Form 4868, and for C corporations that extended Form 1120. Extended partnerships and S corporations come due earlier, on September 15, 2026.
When are estimated tax payments due in 2026?
April 15, June 15, and September 15, 2026, with the final installment on January 15, 2027. The January 15, 2026 payment that opened the year belonged to tax year 2025.
When are the Form 941 deadlines in 2026?
February 2, April 30, July 31, and November 2, 2026 — one month after each quarter closes, adjusted for weekends. The filing for Q4 2026 lands at the start of February 2027.
Does a tax extension give me more time to pay?
No. It only moves the filing deadline. Tax owed was still due April 15, 2026, and interest plus late-payment penalties run on any unpaid balance from that date.
What was the 1099-NEC deadline for 2025 payments?
February 2, 2026, both for filing with the IRS and for giving contractors their copies. If you missed it, file now. Information-return penalties are charged per form and grow with delay.
When is the S corporation election deadline?
For calendar-year businesses, Form 2553 was due March 16, 2026 to take effect for 2026 — roughly two months and 15 days into the tax year. A late election generally applies to 2027 unless you qualify for late-election relief.
What should I do if I already missed a 2026 deadline?
File as soon as you can, even if you can’t pay in full. The failure-to-file penalty (up to 25%) is about ten times the failure-to-pay penalty (0.5% per month). Once the return is in, payment has options.
Source: IRS Publication 509, Tax Calendars (2026 edition). This article is general information, not advice for your specific situation, and reading it doesn’t create a client relationship. Deadlines can differ for fiscal-year filers, some states, and disaster-relief areas. For advice on your facts, book a free consultation with IMAAR Associates CPA, PLLC, the professional practice of a Washington State Licensed CPA and IRS Certifying Acceptance Agent, providing tax preparation, bookkeeping, and fractional CFO services to clients across the United States.