2026 federal tax calendar
2026 U.S. tax filing deadlines for LLCs and corporations
See 2026 deadlines for single-member LLCs, partnerships, C corporations, Form 5472, Form 1120, Form 1065, Form 7004, and late-filing risks.
Main 2026 deadlines for 2025 calendar-year returns
| Business | Main filing | Normal date | With timely extension |
|---|---|---|---|
| Foreign-owned single-member LLC | Form 5472 with pro forma Form 1120 | April 15, 2026 | October 15, 2026 |
| Multi-member LLC taxed as a partnership | Form 1065 and Schedule K-1 | March 16, 2026 | September 15, 2026 |
| Calendar-year C corporation | Form 1120 and Form 5472 when required | April 15, 2026 | October 15, 2026 |
| Calendar-year S corporation | Form 1120-S and Schedule K-1 | March 16, 2026 | September 15, 2026 |
March 15 falls on a Sunday in 2026, so the affected deadline moves to Monday, March 16. Fiscal years, short years, disaster relief, and special rules can change a date.
What Form 7004 changes
A Form 7004 filed on time generally extends the time to file an eligible business return. It generally does not extend the time to pay tax. It also does not extend every information return, owner return, state filing, or payment deadline.
Late-filing risks
A required Form 5472 that is late, missing, or substantially incomplete can generally start with a $25,000 penalty. Partnership and S-corporation late-return penalties can be calculated for each owner and each month or part-month late. Corporate late-filing and late-payment penalties may depend on unpaid tax.
Other conditional filings
Form 1040-NR, Form 1042, Form 1042-S, FBAR, Form 8938, state annual reports, payroll returns, and estimated-tax payments may have separate dates. They do not apply merely because someone owns a U.S. LLC.