IRS Publication 509 is the federal government’s annual tax calendar, listing the due dates for returns, payments, deposits, and information filings across the coming year. The IRS updates it each year and splits it into three calendars so that individuals, employers, and excise tax filers can each find their own dates without wading through the others. Missing a date on any of them triggers automatic penalties, and the IRS does not require that you knew about the deadline before those penalties start running.
Most individual filers only need a handful of dates from the publication. Businesses, employers, and anyone paying tax under the pay-as-you-go system need considerably more.
The Three Calendars Inside Publication 509
Publication 509 is organized into three separate calendars, each aimed at a different kind of taxpayer.1Internal Revenue Service. Publication 509 Tax Calendars The General Tax Calendar covers individual and corporate income tax deadlines. The Employer’s Tax Calendar covers payroll obligations, including withholding deposits and quarterly returns. The Excise Tax Calendar covers taxes on specific goods and activities such as fuel, air transportation, and indoor tanning services.
Each calendar is chronological and split by quarter, and each flags the mechanical rules that shift a due date when it lands on a weekend or holiday. An employer with excise tax obligations may need all three; most individual filers only need one.
Individual Filing and Payment Dates
April 15 is the deadline for filing Form 1040 for the prior tax year.2Internal Revenue Service. When to File Filing Form 4868 by that date gives you an automatic six-month extension to October 15.3Internal Revenue Service. Topic No. 301, When, How and Where to File
The extension is only an extension of time to file. Any tax you owe is still due April 15, and the IRS charges interest and a late-payment penalty on any balance unpaid past that date even if your extension is valid.2Internal Revenue Service. When to File
You can make traditional or Roth IRA contributions for the prior tax year up to the filing deadline, not including extensions. For most people that means April 15.4Internal Revenue Service. Traditional and Roth IRAs – Section: What Is the Deadline to Make Contributions? The 2026 contribution limit is $7,500, or $8,600 if you are 50 or older.5Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
Quarterly Estimated Tax
If you expect to owe $1,000 or more after subtracting withholding and credits, you owe quarterly estimated payments on Form 1040-ES.6Internal Revenue Service. Estimated Taxes This applies to freelancers, independent contractors, landlords, and anyone else whose income is not subject to regular payroll withholding. The four payment periods and their due dates:
- January 1 through March 31: due April 15
- April 1 through May 31: due June 15
- June 1 through August 31: due September 15
- September 1 through December 31: due January 15 of the following year
The income periods are not evenly spaced three-month quarters. The second covers two months and the third covers three, which catches some filers off guard.7Internal Revenue Service. When to Pay Estimated Tax
You can avoid the underpayment penalty if your payments and withholding cover at least 90% of your current-year tax or 100% of the tax shown on your prior-year return, whichever is less. If your adjusted gross income exceeded $150,000 in the prior year ($75,000 if married filing separately), the 100% threshold rises to 110%.8Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
Business Entity Filing Dates
Business deadlines depend on entity type, and the IRS staggers them so that pass-through information reaches individual owners before their personal returns come due.
Calendar-year partnerships filing Form 1065 and S-corporations filing Form 1120-S file by the 15th day of the third month after the tax year ends, which is March 15 for a December 31 year-end.9Internal Revenue Service. Starting or Ending a Business 3 Schedule K-1s to partners or shareholders are due by that same date, because owners need the K-1 to complete their personal returns by April 15.
C-corporations filing Form 1120 have until the 15th day of the fourth month after the tax year ends. For calendar-year filers, that is April 15.9Internal Revenue Service. Starting or Ending a Business 3
All three entity types can request an automatic six-month extension by filing Form 7004.10Internal Revenue Service. Instructions for Form 7004 That moves the partnership and S-corporation deadline to September 15 and the C-corporation deadline to October 15. As with individuals, the extension does not extend time to pay.
Fiscal-year filers apply the same formulas to their own year-end. A partnership with a June 30 year-end files by September 15, the 15th day of the third month afterward.2Internal Revenue Service. When to File
Employer Dates
Employers face the most frequent deadlines of any taxpayer category, with obligations hitting monthly, quarterly, and annually.
Form 941 and Deposits
Form 941 reports federal income tax withholding and both shares of Social Security and Medicare tax.11Internal Revenue Service. About Form 941, Employer’s Quarterly Federal Tax Return It is due on the last day of the month following each quarter: April 30, July 31, October 31, and January 31.
The deposits themselves are made electronically through EFTPS, and the schedule depends on your lookback-period liability.12Internal Revenue Service. Instructions for Form 941 Monthly depositors ($50,000 or less in the lookback) deposit each month’s taxes by the 15th of the following month. Semiweekly depositors (more than $50,000) deposit by the following Wednesday for Wednesday-through-Friday paydays and by the following Friday for Saturday-through-Tuesday paydays. Regardless of schedule, if you accumulate $100,000 or more in taxes on a single day, the deposit is due the next business day, and hitting that threshold automatically moves you to semiweekly for the rest of the year and the next.13Internal Revenue Service. Topic No. 757, Forms 941 and 944 – Deposit Requirements
W-2 and Form 940
The W-2 deadline for tax year 2026 is February 1, 2027, because January 31 that year falls on a Sunday. Employee copies and the SSA filing share the same date.14Internal Revenue Service. General Instructions for Forms W-2 and W-3 (2026)
Form 940, the annual federal unemployment tax return, is due January 31. If you deposited all FUTA taxes on time, you get 10 additional days. For the 2025 return, that is February 2, 2026, or February 10 with timely deposits.15Internal Revenue Service. Instructions for Form 940 (2025)
Information Return Dates
If you pay independent contractors, collect rent, or make other reportable payments, you owe information returns. The two most common forms run on different timelines:
- Form 1099-NEC (nonemployee compensation): due to the recipient and the IRS by January 31, paper or electronic.
- Form 1099-MISC (rents, royalties, other payments): due to recipients by January 31, and to the IRS by February 28 on paper or March 31 electronically.
Both follow the standard weekend and holiday shift rules.16Internal Revenue Service. Instructions for Forms 1099-MISC and 1099-NEC
Excise Tax Dates
Form 720, the Quarterly Federal Excise Tax Return, follows the same quarterly rhythm as Form 941 and is due by the last day of the month following each quarter.17Internal Revenue Service. Basic Things All Businesses Should Know About Excise Tax
- Quarter 1 (January–March): April 30
- Quarter 2 (April–June): July 31
- Quarter 3 (July–September): October 31
- Quarter 4 (October–December): January 31
Some excise taxes reported on Form 720 also require semimonthly deposits through EFTPS when the quarterly liability exceeds $2,500.
How the Due-Date Rules Actually Work
Publication 509 spells out mechanical rules that determine the actual calendar date on which an obligation is due. Getting these wrong by a day can trigger the same automatic penalties as missing the deadline entirely.
Weekends and Holidays
If a due date falls on a Saturday, Sunday, or legal holiday, the deadline moves to the next business day.2Internal Revenue Service. When to File For employment tax deposits, only legal holidays in the District of Columbia count. A state holiday by itself does not push the deposit deadline.13Internal Revenue Service. Topic No. 757, Forms 941 and 944 – Deposit Requirements
Timely Mailing
A return or payment mailed through the U.S. Postal Service is treated as filed or paid on its postmark date, even if the IRS receives it later. The envelope must be properly addressed, carry sufficient postage, and bear a postmark on or before the due date. The rule also applies to designated private delivery services such as FedEx and UPS.18Office of the Law Revision Counsel. 26 U.S. Code 7502 – Timely Mailing Treated as Timely Filing and Paying Keep proof of the postmark or delivery-service tracking if you are close to the deadline.
Disaster Relief
When FEMA declares a federal disaster, the IRS routinely postpones tax deadlines for affected taxpayers. A single announcement can cover filing dates, payment deadlines, and deposit schedules together, and the postponed date replaces the original one without a separate extension request.19Internal Revenue Service. Tax Relief in Disaster Situations If you live or operate in a disaster area, check the IRS disaster relief page before assuming your normal deadlines still apply.
What Happens If You Miss a Date
The IRS charges separate penalties for filing late and paying late, and they can stack.
The failure-to-file penalty is 5% of the unpaid tax for each month or partial month the return is overdue, up to 25%. If the return is more than 60 days late, the minimum penalty is $525 (for returns due in 2026) or 100% of the unpaid tax, whichever is less.20Internal Revenue Service. Failure to File Penalty
The failure-to-pay penalty is 0.5% of the unpaid balance per month, also capped at 25%. It drops to 0.25% per month for taxpayers on a timely-filed installment agreement, and rises to 1% per month if the IRS issues a notice of intent to levy and you don’t pay within 10 days.21Internal Revenue Service. Topic No. 653, IRS Notices and Bills, Penalties and Interest Charges
When both penalties apply in the same month, the failure-to-file penalty is reduced by the failure-to-pay amount, so the combined charge is 5% per month rather than 5.5%. Filing on time, even without paying, cuts the maximum combined exposure roughly in half compared with doing nothing.