Small Business Tax Deadlines 2027: The Full Calendar
Every federal due date by entity type — returns, extensions, estimates, payroll forms, and information returns — in one table
Reviewed by the Fairlight Accounting cross-border tax team — U.S. & Canadian Tax Desks
The 2027 filing season covers tax year 2026. Partnership and S corporation returns are due March 15, 2027; sole proprietor and C corporation returns April 15; quarterly estimates April 15, June 15, September 15, and January 18, 2028; W-2s and 1099-NECs by February 1, 2027. A deadline on a weekend or federal holiday moves to the next business day.
On this page
The 2027 calendar by entity
| Date (2027) | Sole proprietor / single-member LLC | Partnership / multi-member LLC | S corporation | C corporation (calendar year) |
|---|---|---|---|---|
| January 15 | Q4 2026 estimated tax (Form 1040-ES) | — | — | Q4 2026 estimate was due December 15, 2026 |
| February 1 | W-2s to employees and SSA; 1099-NEC to recipients and IRS; Form 940; Q4 Form 941 (January 31 is a Sunday) | Same payroll and 1099 deadlines | Same | Same |
| February 16 | 1099-B, 1099-S, and 1099-MISC box 8 and 10 amounts to recipients (February 15 is Washington's Birthday) | Same | Same | Same |
| March 1 / March 31 | 1099-MISC and other 1099s to IRS (paper February 28 → March 1; electronic March 31) | Same | Same | Same |
| March 15 | — | Form 1065 due; Schedule K-1s to partners; Form 7004 extension to September 15 | Form 1120-S due; K-1s to shareholders; Form 7004 extension to September 15; Form 2553 for a 2027 S election | — |
| April 15 | Form 1040 with Schedule C due; Form 4868 extension to October 15; Q1 2027 estimate; 2026 IRA and HSA contributions; FBAR (automatic extension to October 15) | Q1 estimate for partners | Q1 estimate for shareholders | Form 1120 due; Form 7004 extension to October 15; Q1 2027 estimate; 2026 balance due |
| April 30 | Q1 Form 941 | Same | Same | Same |
| May 17 | Form 990 for calendar-year nonprofits (May 15 is a Saturday) | — | — | — |
| June 15 | Q2 estimate; Form 1040 for U.S. citizens abroad (automatic two-month extension) | Q2 estimate | Q2 estimate | Q2 estimate |
| August 2 | Form 5500 for calendar-year retirement plans; Q2 Form 941 (July 31 is a Saturday) | Same | Same | Same |
| September 15 | Q3 estimate | Extended Form 1065 due | Extended Form 1120-S due | Q3 estimate |
| October 15 | Extended Form 1040 due; extended FBAR | — | — | Extended Form 1120 due |
| November 1 | Q3 Form 941 (October 31 is a Sunday) | Same | Same | Same |
| December 15 | — | — | — | Q4 estimate |
| January 18, 2028 | Q4 2027 estimate (January 15, 2028 is a Saturday and January 17 is Martin Luther King Jr. Day) | — | — | — |
The weekend and holiday shifts above are computed from the 2027 calendar under the Saturday, Sunday, and legal-holiday rule; Publication 509 for 2027 had not been released as of September 29, 2026.
Payroll deadlines through the year
Form 941 is due the last day of the month after each quarter (April 30; July 31 → August 2; October 31 → November 1; and January 31, 2028 for Q4 2027 — a Monday). Payroll tax deposits run on the employer's monthly or semiweekly schedule throughout (the deposit schedule guide). Form 940 and the W-2/W-3 package are due February 1, 2027 for 2026. State payroll returns follow their own calendars, mostly quarterly.
Information returns
Form 1099-NEC (nonemployee compensation) is due to recipients and the IRS by January 31 — February 1 in 2027. Most other 1099s (1099-MISC for rents and other payments, 1099-K from payment processors, 1099-INT, 1099-DIV) go to recipients by January 31 — 1099-B, 1099-S, and certain 1099-MISC amounts by February 15, which is February 16 in 2027 — and to the IRS by the end of February on paper or March 31 electronically. Electronic filing is required for filers with ten or more information returns in aggregate. Form W-9 collection from every vendor before the first payment is what makes the January deadline workable.
Extensions — what they do and don't do
An extension extends the time to file, not the time to pay. Form 4868 (individuals) and Form 7004 (entities) are automatic — filed by the original due date, they push the filing deadline six months (five and a half for estates and trusts) — but any tax owed is still due on the original date, with interest and the failure-to-pay penalty accruing on any shortfall. The extension payment is an estimate of the balance due, made with the extension request. Partnerships and S corporations owe no federal tax themselves in most cases, so their extensions are truly free; the partners' and shareholders' own returns still need the K-1s, which is why a March 15 entity extension pushes the owners' April 15 filings to October.
Estimated taxes
Four installments for individuals (April 15, June 15, September 15, January 15 — shifted for weekends and holidays) covering income tax and self-employment tax on income not subject to withholding; four for C corporations (the 15th of the fourth, sixth, ninth, and twelfth months). The safe harbor guide covers how much; the penalty for missing an installment is computed quarter by quarter on Form 2210.
Worked example
An S corporation with two shareholders and six employees, calendar year: February 1 — W-2s issued and filed, Form 940 filed, Q4 941 filed, 1099-NECs to the three subcontractors; March 15 — Form 1120-S filed with K-1s (or Form 7004 filed, pushing it to September 15); April 15 — each shareholder files Form 1040 (or extends to October 15) with the balance due paid, and pays the Q1 estimate; April 30, August 2, November 1 — Forms 941; June 15 and September 15 — estimates; August 2 — Form 5500 for the company's 401(k); January 18, 2028 — the Q4 estimate. The state's S corporation return, annual report, and payroll filings run alongside on the state's calendar. A missed March 15 for the 1120-S costs a per-shareholder, per-month penalty even though the entity owes no tax — the extension takes two minutes and avoids it.
Frequently asked questions
When are partnership and S corporation returns due?
March 15 for calendar-year entities (Forms 1065 and 1120-S), with an automatic six-month extension to September 15 via Form 7004. K-1s to owners are due the same day.
When are quarterly estimates due?
April 15, June 15, September 15, and January 15 of the following year for individuals, shifted to the next business day when they fall on a weekend or holiday. In 2027, the Q4 installment for 2027 is due January 18, 2028.
When are 1099s due?
Form 1099-NEC by January 31 (February 1 in 2027) to both recipients and the IRS. Most other 1099s to recipients by January 31 (1099-B, 1099-S, and certain 1099-MISC amounts by February 16 in 2027) and to the IRS by February 28 (paper) or March 31 (electronic).
What if a deadline falls on a weekend?
It moves to the next business day. Several 2027 dates shift: January 31 (Sunday) to February 1, May 15 (Saturday) to May 17, July 31 (Saturday) to August 2, October 31 (Sunday) to November 1, and January 15, 2028 (Saturday, followed by a federal holiday) to January 18.
Official sources
Publication 509 states: “Generally, if a due date for performing any act for tax purposes falls on a Saturday, Sunday, or legal holiday, the act is considered to be performed timely if it is performed no later than the next day that isn’t a Saturday, Sunday, or legal holiday.” — Internal Revenue Service, Publication 509, Tax Calendars, https://www.irs.gov/publications/p509
The IRS states: “For estimated tax purposes, the year is divided into four payment periods. Each period has a specific payment due date.” — Internal Revenue Service, Estimated taxes, https://www.irs.gov/businesses/small-businesses-self-employed/estimated-taxes
Next step
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