2026 Tax Deadlines for Individuals and Small Businesses
Missing a tax deadline is one of the most avoidable — and most expensive — mistakes a small-business owner can make. Here's the short version, then the full 2026 calendar.
Direct answer: For most people, 2025 individual returns are due April 15, 2026. Calendar-year S-corporations and partnerships file earlier, by March 16, 2026. And if you pay quarterly estimates, your Q4 2025 payment is due January 15, 2026. Extensions push the filing date out, never the payment date.
When are individual taxes due in 2026?
The federal deadline to file your 2025 Form 1040 and pay any balance due is Wednesday, April 15, 2026.
If you can't file by then, you can request an automatic extension (Form 4868) that moves your filing deadline to October 15, 2026. The catch that trips people up every year: an extension is only an extension of time to file. Whatever you owe is still due April 15, 2026. If you don't pay by then, interest and a failure-to-pay penalty begin to accrue on the unpaid balance.
What are the 2026 business tax deadlines?
Business deadlines depend on your entity type. Here are the key dates for calendar-year filers:
| Entity type | Form | 2026 filing deadline | Extended deadline |
|---|---|---|---|
| S-corporation | 1120-S | March 16, 2026 | September 15, 2026 |
| Partnership / multi-member LLC | 1065 | March 16, 2026 | September 15, 2026 |
| C-corporation | 1120 | April 15, 2026 | October 15, 2026 |
| Sole proprietor (Schedule C) | 1040 | April 15, 2026 | October 15, 2026 |
| Single-member LLC (default) | 1040 | April 15, 2026 | October 15, 2026 |
Why do S-corps and partnerships file a month earlier? Because they're pass-through entities — they issue Schedule K-1s to owners, who then need that information to complete their personal returns by April 15. The earlier deadline keeps the chain moving.
Note that March 15, 2026 lands on a Sunday, so the pass-through deadline shifts to Monday, March 16, 2026.
When are quarterly estimated taxes due in 2026?
If you're self-employed, a business owner, or you have significant income that isn't subject to withholding, you likely owe quarterly estimated taxes. Here's the schedule that spans the 2025 and 2026 tax years:
| Payment | Covers income earned | Due date |
|---|---|---|
| 2025 Q4 | Sept 1 – Dec 31, 2025 | January 15, 2026 |
| 2026 Q1 | Jan 1 – Mar 31, 2026 | April 15, 2026 |
| 2026 Q2 | Apr 1 – May 31, 2026 | June 15, 2026 |
| 2026 Q3 | Jun 1 – Aug 31, 2026 | September 15, 2026 |
| 2026 Q4 | Sept 1 – Dec 31, 2026 | January 15, 2027 |
If a due date falls on a weekend or federal holiday, the payment is on time if made the next business day. (Not sure whether you even need to pay estimates? Our post on quarterly estimated taxes walks through the rules.)
Other 2026 dates worth putting on the calendar
A few deadlines that aren't the "big four" but still catch owners off guard:
- January 31, 2026 — Deadline to furnish W-2s to employees and 1099-NECs to contractors, and to file them with the SSA/IRS. (For 2025 payments, the 1099-NEC reporting threshold is still $600. Beginning with 2026 payments, that threshold rises to $2,000.)
- April 15, 2026 — Last day to make 2025 IRA and HSA contributions.
- September 15, 2026 — Extended deadline for S-corp and partnership returns.
- October 15, 2026 — Extended deadline for individual and C-corp returns.
What happens if you miss a deadline?
The IRS charges two separate penalties, and the bigger one is for not filing:
- Failure-to-file penalty: 5% of the unpaid tax per month (or part of a month), up to 25%.
- Failure-to-pay penalty: 0.5% of the unpaid tax per month, up to 25%.
- Interest: charged on top of both, at a rate the IRS sets quarterly.
The takeaway: even if you can't pay in full, file on time (or file an extension). Filing avoids the much larger failure-to-file penalty, and you can set up a payment plan for the balance.
A quick word of advice
Most of the pain around tax deadlines comes from scrambling at the last minute — not from the deadlines themselves. If you know your S-corp return is due in mid-March, you want clean books by February, which means you want organized records all year. If that feels like a stretch right now, that's exactly what a good CPA relationship is for.
At Frazier Industries, our tax preparation service keeps your filing calendar mapped out so nothing sneaks up on you. If a deadline is bearing down and you're not sure where you stand, book a consultation and we'll get you sorted.
This article is general information, not tax advice. Deadlines can shift for disaster-area relief, fiscal-year filers, and specific situations — check with a CPA about your circumstances.
Frequently asked questions
When are 2025 individual tax returns due in 2026? Individual returns (Form 1040) for the 2025 tax year are due Wednesday, April 15, 2026. An extension moves the filing deadline to October 15, 2026, but not the payment deadline.
What is the S-corp and partnership tax deadline for 2026? Calendar-year S-corporations and partnerships must file by March 16, 2026. The usual March 15 date falls on a Sunday in 2026, so it shifts to the next business day.
Does a tax extension give me more time to pay? No. An extension only extends the time to file the return. Any tax you owe is still due by the original deadline (April 15, 2026 for most individuals), or interest and penalties start to accrue.
When is the last 2025 estimated tax payment due? The fourth-quarter estimated payment for the 2025 tax year is due January 15, 2026. The first 2026 payment follows on April 15, 2026.
What happens if I miss a tax deadline? You may face a failure-to-file penalty (up to 5% of unpaid tax per month), a failure-to-pay penalty, and interest. Filing on time — even if you can't pay in full — avoids the larger failure-to-file penalty.