2026 small business tax deadlines: a federal filing calendar

Because January 31, 2026 falls on a Saturday, key January 31 reporting deadlines move to Monday, February 2, 2026. Employers generally furnish 2025 Forms W-2 to employees and file Copy A with the Social Security Administration by that date. Form 1099-NEC for reportable 2025 nonemployee compensation is also due to the IRS and recipient by February 2, 2026.

Prepare these forms from reconciled payroll and vendor records. Year-end reporting is much easier when W-9 collection, contractor classification, payroll adjustments, and taxable fringe benefits were handled during the year rather than reconstructed in January.

For calendar-year entities, March 15 falls on a Sunday in 2026, so the deadline moves to March 16. Calendar-year partnerships file Form 1065 and furnish Schedule K-1. Calendar-year S corporations file Form 1120-S and furnish shareholder K-1s. March 16 is also the general 2026 deadline for a calendar-year entity making a timely S corporation election effective January 1, 2026.

A partnership or S corporation should not wait for March to identify ownership changes, partner or shareholder loans, distributions, contributions, or payroll differences. Those items often determine whether the return can be prepared from the closed books without a second cleanup cycle.

A calendar-year C corporation generally files Form 1120 by April 15. Individuals, including many sole proprietors and owners receiving pass-through income, generally file the 2025 Form 1040 by April 15, 2026. The first 2026 individual estimated-tax installment is also due April 15.

Entity returns and owner returns are connected but not interchangeable. A business may need to finish its books, issue a K-1, or complete corporate tax work before an owner can finish a personal return. Build the calendar around those dependencies rather than treating every April 15 item as an isolated deadline.

For calendar-year individuals making estimated payments, the 2026 schedule is uneven by design. The IRS payment periods are not four equal three-month quarters, so the due dates should be loaded into the calendar explicitly.

Form 941 is generally due by the last day of the month after each calendar quarter: April 30, July 31, October 31, and January 31, subject to weekend and holiday rules and a potential additional 10 days when all deposits were made on time. Payroll tax deposit deadlines are separate and depend on the employer's deposit schedule.

That distinction is important operationally. A company can file Form 941 on time and still have late payroll tax deposits from earlier in the quarter. Reconcile deposits, payroll reports, and payroll liabilities monthly instead of using the quarterly return as the only control.

Form 7004 can provide an automatic filing extension for many business returns, but an extension to file generally does not extend the time to pay tax. A useful calendar therefore tracks return deadlines, payment deadlines, estimated-tax dates, payroll deposit dates, and state obligations separately.

When an extension is filed, keep the extension confirmation, payment calculation, payment evidence, revised filing deadline, and the owner of the remaining preparation work together. Otherwise an extension can remove the immediate deadline while leaving the underlying tax project unowned.

The federal dates above are only one layer. State income and franchise taxes, sales tax, payroll withholding, unemployment, annual reports, registered-agent renewals, and local licenses can follow different schedules. The company's operating footprint determines which of those calendars apply.

Review the footprint when the business hires in a new state, opens a location, forms or qualifies an entity, or materially changes where it sells and operates. The deadline list should change when the business changes.

A deadline calendar works best when it is connected to the monthly close. Reconciled cash, payroll, debt, fixed assets, owner activity, and state accounts reduce the amount of tax-season reconstruction and make it easier to estimate what will be due before the filing date arrives.

For each material filing, keep four fields visible throughout the year: the filing period, due date, responsible owner, and evidence of completion. Add an extension date and payment status when applicable. That small record is more useful than a long calendar nobody updates.