Small Business Tax Deadlines: A Month-by-Month Guide

Small business tax deadlines depend on how your business is structured and whether you have employees. Some dates apply to every owner, such as estimated tax payments. Others apply only to certain businesses, such as partnership returns or payroll filings. Missing a date can lead to penalties, so it helps to see the whole year in one place.

This guide walks through the main federal deadlines month by month, then groups them by business type. It also explains extensions and gives a sample year for a sole proprietor with an employee. The dates below are the usual ones for calendar-year taxpayers. This article is general information, not tax advice, so confirm your own dates with the IRS tax calendar or a tax professional.

What Are Small Business Tax Deadlines?

Small business tax deadlines are the dates by which you must file returns, pay taxes, or send required forms to the IRS and to the people you pay. They cover several kinds of tax:

• Income tax returns
• Estimated tax payments
• Payroll tax deposits and returns
• Information forms for employees and contractors

A few rules apply across the board:

• Weekends and holidays. When a due date falls on a Saturday, Sunday, or legal holiday, it generally moves to the next business day. For example, the IRS calendar for 2026 shows the third-quarter Form 941 deadline on November 2, because October 31 fell on a Saturday.
• Electronic payments. For EFTPS payments, the IRS says you must schedule the payment by 8 p.m. Eastern Time at least one calendar day before the due date. Learn more about EFTPS on the IRS site.
• Disasters. Taxpayers affected by disasters may get filing and payment extensions, so check the IRS site for your state.
• State and local taxes. This guide covers federal deadlines. Your state and city may have separate dates, so check with your state tax agency.

Small Business Tax Deadlines by Month

January

• January 15: Individuals pay the final installment of the prior year’s estimated tax. Sole proprietors, partners, and S corporation shareholders use Form 1040-ES.
• January 15: If you deposit payroll taxes monthly, deposit the tax for payments made in December.
• January 31: Give Form W-2 to employees who worked for you in the prior year.
• January 31: File Form 1099-NEC for nonemployee compensation you paid in the prior year, and give recipients their copies.
• End of January: File Form 940 and the fourth-quarter Form 941. If you deposited all required taxes on time, you generally have until February 10.

March

• March 15: Partnerships file Form 1065 and give each partner a Schedule K-1.
• March 15: S corporations file Form 1120-S and give each shareholder a Schedule K-1.
• March 15: To elect S corporation status starting with the current calendar year, file Form 2553. If you file it late, the election generally starts with the following year.

April

• April 15: Individuals, including sole proprietors, file Form 1040 and pay any tax due.
• April 15: C corporations file Form 1120 and pay any tax due.
• April 15: The first estimated tax installment is due for individuals and corporations.
• April 30: File Form 941 for the first quarter.
• April 30: Deposit federal unemployment (FUTA) tax owed through March if it is more than $500.

June

• June 15: The second estimated tax installment is due for individuals and corporations.

July

• July 31: File Form 941 for the second quarter.
• July 31: Deposit FUTA tax owed through June if it is more than $500.

September

• September 15: The third estimated tax installment is due for individuals and corporations.
• September 15: Partnerships and S corporations that timely requested a six-month extension file their returns.

October

• October 15: Individuals who timely requested a six-month extension file Form 1040.
• October 15: Corporations that timely requested a six-month extension file Form 1120.
• October 31: File Form 941 for the third quarter.
• October 31: Deposit FUTA tax owed through September if it is more than $500.

December

• December 15: Corporations pay the fourth installment of their estimated tax.

Every Month

If you have employees, payroll tax deposits follow either the monthly or the semiweekly deposit rule. Monthly depositors generally deposit by the 15th of the following month. Semiweekly depositors deposit on Wednesdays or Fridays, depending on the day of the week they paid wages. Our guide to small business payroll explains payroll taxes in more detail.

Small Business Tax Deadlines by Business Type

Sole Proprietors

• File Form 1040, with Schedule C, by April 15.
• Pay estimated tax on April 15, June 15, September 15, and January 15.
• If you have employees, follow the payroll dates above. If you paid contractors, send Form 1099-NEC by January 31.

Partnerships

• File Form 1065 by March 15, or request an extension on Form 7004.
• Each partner generally pays estimated tax individually.

S Corporations

• File Form 1120-S by March 15, or request an extension on Form 7004.
• Shareholders generally pay estimated tax if they expect to owe $1,000 or more.

C Corporations

• File Form 1120 by April 15, or request an extension on Form 7004.
• Pay estimated tax on April 15, June 15, September 15, and December 15.

Employers

• Make payroll tax deposits on your monthly or semiweekly schedule.
• File Form 941 quarterly, and Form 940 each year.
• Give W-2 forms to employees by January 31.

How Extensions Work

An extension gives you more time to file your return. Individuals request an automatic six-month extension with Form 4868, and entities such as partnerships, S corporations, and corporations use Form 7004.

The IRS calendar says to deposit your estimated tax when you request an automatic extension, so plan your payment even if you file later. The extended due dates are generally September 15 for partnership and S corporation returns, and October 15 for individual and corporate returns.

Small Business Tax Deadlines Example (Hypothetical)

Here is a sample year for a sole proprietor who has one employee and paid one contractor. These details are hypothetical.

• January 15: Pay the last estimated tax installment for the prior year, and deposit December payroll tax if she is a monthly depositor.
• January 31: Give her employee a Form W-2, and file and send a Form 1099-NEC to her contractor.
• April 15: File her Form 1040 with Schedule C, and pay her first estimated tax installment.
• April 30: File Form 941 for the first quarter.
• June 15: Pay her second estimated tax installment.
• July 31: File Form 941 for the second quarter.
• September 15: Pay her third estimated tax installment.
• October 31: File Form 941 for the third quarter.
• Each month: Deposit payroll taxes by the 15th if she is a monthly depositor.

Her estimated tax payments are separate from her payroll taxes. Our guide to estimated taxes for small business explains how to figure those payments.

How to Track Small Business Tax Deadlines

• Put every date on a calendar. Add reminders a couple of weeks ahead, so you have time to prepare.
• Use the IRS tax calendar. The IRS tax calendar lists the dates for each quarter and is updated each year.
• Keep your books current. Our guide to small business bookkeeping explains how to keep records organized, and our guide to small business tax deductions explains what you may be able to subtract.
• Set money aside. Estimated tax and payroll tax payments are easier when you plan for them ahead of time.
• Ask a professional. A tax professional can confirm your dates, which depend on your structure. Our guide to a small business tax accountant explains how to choose one.

What Happens If You Miss a Deadline?

Late filing and late payment can lead to penalties and interest. For estimated taxes, the IRS says you may be charged a penalty if you do not pay enough by the due date of each payment period, even if you are due a refund when you file. The IRS penalties page explains the different penalties.

Common Tax Deadline Mistakes

• Treating an extension to file as a payment extension. The IRS says to deposit your estimated tax with the extension request.
• Forgetting payroll deadlines. Deposits and quarterly returns come up all year.
• Missing Form 1099-NEC and Form W-2 dates. They fall at the end of January.
• Missing the S corporation election date. A late Form 2553 can push the election to the next year.
• Ignoring state deadlines. Your state may have separate dates.
• Not planning for weekends. Check whether a date moves to the next business day.

Frequently Asked Questions

What is the most important tax deadline for a small business?

It depends on your structure. Sole proprietors and C corporations file by April 15, while partnerships and S corporations file by March 15.

When are estimated taxes due?

Individuals pay on April 15, June 15, September 15, and January 15. Corporations pay on April 15, June 15, September 15, and December 15.

When do I file Form 1099-NEC?

Generally by January 31, for payments made in the prior year. If January 31 falls on a weekend, the deadline moves to the next business day.

Can I get an extension?

Yes. Individuals can request an automatic six-month extension with Form 4868, and entities can use Form 7004. The IRS says to deposit your estimated tax when you request it.

What if a deadline falls on a weekend?

It generally moves to the next business day.

Do state tax deadlines match federal deadlines?

Not always. Check with your state tax agency.

Conclusion

Small business tax deadlines are easier to manage when you know which ones apply to your business. Write down your dates, use the IRS tax calendar, keep your books up to date, and plan your payments ahead of time. If you are unsure which dates apply to you, ask a qualified tax professional. This guide is general information and not tax advice.