Small business taxes: which return, when it's due

This page covers federal business taxes. State taxes differ by state, so each state’s Stay compliant page has its own calendar. Pick yours at Start a business.

The five kinds of federal business tax

The IRS names five general types on its Business taxes page. A business owes some of them, not always all five.

• Income tax. Every business except a partnership files an annual income tax return. A partnership files an information return instead.
• Estimated tax. Income and self-employment tax are paid in regular installments during the year. See quarterly estimated taxes.
• Self-employment tax. Social Security and Medicare tax for people who work for themselves. See self-employment tax.
• Employment taxes. Owed when you have employees. The IRS employment taxes page has the forms.
• Excise tax. Owed only for certain activities and products. The IRS excise tax page lists them.

Which return you file

The return follows the business structure. An LLC’s federal return depends on its tax classification, not on the LLC itself. See LLC vs S corp: entity vs tax election.

Structure	Return	K-1	Due	Extension
Sole proprietor, or single-member LLC by default	Form 1040 with Schedule C	None	15th day of the 4th month after the end of your tax year	Form 4868
Partnership, or multi-member LLC by default	Form 1065	Schedule K-1 (Form 1065)	15th day of the 3rd month after the end of the partnership’s tax year	Form 7004
S corporation	Form 1120-S	Schedule K-1 (Form 1120-S)	15th day of the 3rd month after the end of the corporation’s tax year	Form 7004
C corporation	Form 1120	None	15th day of the 4th month after the end of the corporation’s tax year	Form 7004

A due date that lands on a Saturday, Sunday or legal holiday moves to the next day that isn’t a Saturday, Sunday or legal holiday.

An S corporation or partnership files its return, then hands each owner a K-1 showing that owner’s share. The owner reports that share on a personal return. A single-member LLC has no K-1 because there is only one owner. A multi-member LLC is a partnership for federal tax unless it files an election to be taxed as a corporation.

The calendar for tax year 2026

Most owners file on a calendar year, so the dates below assume a tax year that ends December 31, 2026. A business with a different tax year counts the same months from its own year end.

These are the dates for returns and forms filed in 2027. Estimated payments for 2026 run through January 2027.

What	When	Rule
Final 2026 estimated payment	January 15, 2027	Set by the IRS estimated tax schedule
W-2 to employees and Form 1099-NEC to contractors	February 1, 2027*	January 31, moved because the 31st is a Sunday
Form 1065 and Form 1120-S	March 15, 2027*	15th day of the 3rd month after the end of the partnership’s tax year
Form 1040 with Schedule C and Form 1120	April 15, 2027*	15th day of the 4th month after the end of your tax year
Extended Form 1065 and Form 1120-S	September 15, 2027*	Six months after the original due date
Extended Form 1040 with Schedule C and Form 1120	October 15, 2027*	Six months after the original due date

* The IRS had not published its 2027 calendar when this was checked. These dates are worked out from the rules in the table, so confirm them on the IRS tax calendar.

The 1099 and W-2 rows apply only if you paid contractors $2,000 or more or had employees. The 1099 guide covers who gets a form.

Extensions

An extension gives six months to file, not to pay. Individual returns use Form 4868. Partnership, S corporation and C corporation returns use Form 7004. The IRS says the extension is only for filing your return. Pay what you expect to owe by the original due date, or interest and late-payment penalties can start. An extension also does not move the estimated payment dates. The IRS explains the process on its extension page.

If you have employees

File Form 941 every quarter, due the last day of the first calendar month after the calendar quarter ends. Two exceptions: the IRS moves the smallest employers, those whose yearly liability for Social Security, Medicare and withheld income tax is $1,000 or less, to Form 944, filed once a year, and only once it has told you in writing; and farm employers file Form 943 instead. File Form 940, the yearly unemployment tax return, due the last day of the first calendar month after the calendar year ends. Give each employee a W-2 by January 31, which falls on February 1 in 2027.*

Keep employment tax records for at least 4 years after the tax is due or paid, whichever is later. The IRS employment taxes page lists every employer form and deposit rule.

Records

Records are what you rely on if the IRS asks how a number on a return was reached. That means income, expenses, payroll and the returns themselves.

Keep general business records for 3 years if none of the longer-period situations apply. The IRS lists those cases on its records page. Check the official source if you are unsure which period fits. Employment tax records have their own, longer period, covered above.

Do this

1. Put the dates on a calendar. Start with the rows above, then confirm each one on the IRS tax calendar when the IRS publishes it.
2. Confirm your return type from your entity and any tax election. The IRS LLC page explains the default for each kind of LLC. Check with a CPA if you are unsure.
3. Set up estimated payments if you expect to owe. The estimated taxes guide has the schedule, and you pay on the IRS estimated taxes page.
4. Collect a W-9 before you pay a contractor. Ask for it up front so the Form 1099-NEC is ready in January. The 1099 guide explains why, and the IRS Form W-9 page has the form.
5. Open your state’s Stay compliant page for the state calendar. Choose your state.