For calendar-year businesses filing for tax year 2026, these are the federal dates that matter. When a deadline lands on a weekend or federal holiday it moves to the next business day, and the dates below already reflect that.
The short list
| Date | What’s due | Who it applies to |
|---|---|---|
| January 15, 2027 | Q4 2026 estimated tax payment | Owners of sole props, LLCs, S-corps and partnerships who pay estimated tax |
| February 1, 2027 | W-2s to employees and the SSA; 1099-NECs to contractors and the IRS; Form 940; Q4 2026 Form 941 | Any business with employees or contractors |
| March 15, 2027 | S-corp (Form 1120-S) and partnership (Form 1065) returns and K-1s; Form 2553 to be an S-corp for 2027 | S-corps, partnerships, multi-member LLCs |
| April 15, 2027 | Individual returns (Form 1040 with Schedule C), C-corp returns (Form 1120), Q1 2027 estimated tax, extension requests | Sole proprietors, single-member LLCs, C-corps, every owner’s personal return |
| April 30, 2027 | Q1 2027 Form 941 | Employers |
| June 15, 2027 | Q2 2027 estimated tax payment | Estimated-tax payers |
| August 2, 2027 | Q2 2027 Form 941 | Employers |
| September 15, 2027 | Extended 1120-S and 1065 returns; Q3 2027 estimated tax | Extended S-corps and partnerships; estimated-tax payers |
| October 15, 2027 | Extended 1040 and 1120 returns | Anyone who extended their individual or C-corp return |
| November 1, 2027 | Q3 2027 Form 941 | Employers |
| January 18, 2028 | Q4 2027 estimated tax payment | Estimated-tax payers |
Still working on 2025? Extended 2025 individual and C-corp returns are due October 15, 2026.
Which return does my business file?
| Business type | Federal return | Due (calendar year) |
|---|---|---|
| Sole proprietor or single-member LLC | Form 1040, Schedule C | April 15, 2027 |
| Multi-member LLC or partnership | Form 1065, plus K-1s to partners | March 15, 2027 |
| S-corp (including an LLC taxed as one) | Form 1120-S, plus K-1s to shareholders | March 15, 2027 |
| C-corp | Form 1120 | April 15, 2027 |
S-corp and partnership owners still file their own Form 1040 by April 15, using the K-1 from the business.
What changed for 2026 payments: the 1099 threshold
Starting with payments made in 2026, the reporting threshold for Form 1099-NEC (contractors) and most Form 1099-MISC boxes rose from $600 to $2,000. You still need a W-9 from every contractor, and contractors still owe tax on everything you pay them, even when no 1099 is required.
Estimated taxes, briefly
If you expect to owe $1,000 or more when you file, the IRS expects you to pay during the year. Owners usually pay quarterly with Form 1040-ES. You generally avoid an underpayment penalty if your payments cover at least 90% of this year’s tax or 100% of last year’s (110% if last year’s adjusted gross income was over $150,000).
Extensions extend filing, not payment
Form 7004 (businesses) and Form 4868 (individuals) each give six more months to file. They don’t extend the time to pay. Estimate what you owe and pay it by the original date to avoid late-payment penalties and interest.
Don’t forget state deadlines
States set their own dates for income, franchise and sales tax, and many differ from the federal calendar. Sales tax is often due monthly or quarterly. If you sell in more than one state, each one can have its own schedule.
Let someone else watch the calendar
On our Bookkeeping & Tax plan, we keep your books current every month, plan your estimated payments, file your 1099s and prepare your business and owner returns before these dates. The first date on this list is January 15, 2027, and catch-up comes before anything else, so booking in the fall leaves time to get your 2026 books current first. Book a free 15-minute call, or check where you stand with the free AutoTaxScore.
Dates are for calendar-year filers and federal returns. IRS disaster relief can postpone deadlines for affected areas.