The short answer
- For calendar-year companies, partnership and S corporation returns are due on the 15th day of the 3rd month (March 15), corporate returns and Form 5472 on the 15th day of the 4th month (April 15).
- When a due date falls on a weekend or legal holiday, it moves to the next business day. In 2026, partnership and S corporation returns were due March 16.
- Form 7004 gives an automatic extension, generally of 6 months, to file business returns. It does not extend the time to pay.
- Corporations pay estimated tax on the 15th day of the 4th, 6th, 9th and 12th months if they expect to owe $500 or more. Individuals pay on April 15, June 15, September 15 and January 15.
- A nonresident alien without U.S. wages files Form 1040-NR by June 15.
Table of contents
Most IRS penalties for small companies owned from abroad come from dates, not from complicated tax questions: a return filed late, an extension not requested, an estimated payment forgotten. This guide collects the federal deadlines that matter for U.S. companies and their foreign owners, with the calendar for the 2027 filing season.
The dates below apply to calendar-year taxpayers. Companies with a different fiscal year use the same rules counted from the end of their own year.
Which return, which deadline
| Who | Form | Due date |
|---|---|---|
| Multi-member LLC taxed as a partnership | 1065 | 15th day of the 3rd month |
| S corporation | 1120-S | 15th day of the 3rd month |
| C corporation | 1120 | 15th day of the 4th month |
| Single-member LLC owned by a foreign person | 5472 with pro forma 1120 | Due date of the Form 1120: 15th day of the 4th month |
| Nonresident alien without U.S. wages | 1040-NR | 15th day of the 6th month |
| Nonresident alien with U.S. wages subject to withholding | 1040-NR | 15th day of the 4th month |
A single-member LLC owned by a U.S. resident does not file its own income tax return: its activity goes on the owner’s personal return. That rule does not apply to foreign owners, whose LLC files Form 5472 with a pro forma Form 1120 when it has reportable transactions, even with zero revenue.
If a due date falls on a Saturday, Sunday or legal holiday, it moves to the next business day. In 2026, March 15 fell on a Sunday, so partnership and S corporation returns were due March 16.
Calendar for the 2027 filing season (tax year 2026)
| Date | Deadline |
|---|---|
| Friday, January 15, 2027 | Last estimated tax payment for 2026, individuals |
| Monday, March 15, 2027 | Forms 1065 and 1120-S |
| Thursday, April 15, 2027 | Form 1120, Form 5472 with pro forma 1120, Form 1040-NR with U.S. wages |
| Tuesday, June 15, 2027 | Form 1040-NR without U.S. wages |
| Wednesday, September 15, 2027 | Forms 1065 and 1120-S with extension |
| Friday, October 15, 2027 | Form 1120 and Form 5472 with extension |
The extended dates assume the automatic 6-month extension requested with Form 7004 by the original due date.
Extensions: more time to file, not to pay
Form 7004 gives an automatic extension to file most business returns, including Forms 1065, 1120-S and 1120. The extension period is generally 6 months. It must be filed by the regular due date.
An extension does not extend the time to pay. Tax not paid by the original due date accrues interest and the failure-to-pay penalty, even when the return is filed on time under the extension.
Estimated tax payments
Corporations must make estimated tax payments if they expect to owe $500 or more for the year. The installments are due on the 15th day of the 4th, 6th, 9th and 12th months of the tax year: April 15, June 15, September 15 and December 15 for a calendar-year corporation.
Individuals who expect to owe tax not covered by withholding pay estimated tax on April 15, June 15, September 15 and January 15 of the following year. For a foreign owner, this matters only if they have U.S. taxable income of their own, for example income effectively connected with a U.S. trade or business. Whether that applies is a question for a tax professional. Our guide to U.S. business taxes for non-resident owners explains the rule.
What happens when you miss a deadline
- Failure to file: 5% of the unpaid tax for each month or part of a month the return is late, up to 25%. If the return is more than 60 days late, a minimum penalty applies.
- Failure to pay: 0.5% of the unpaid tax per month or part of a month, up to 25%.
- Form 5472: $25,000 for each form not filed, with additional penalties if the failure continues after an IRS notice.
- Interest runs on unpaid tax until it is paid.
More on penalties and how returns are selected for review in our guide to avoiding IRS penalties and audits.
If you never filed
If you do not file, the IRS may prepare a substitute return for you. The IRS itself notes that this return might not give you credit for deductions you may be entitled to. It then sends a notice proposing an assessment, and you have 90 days to file your past due return or to petition the Tax Court.
Filing late is always better than not filing: it stops the failure-to-file penalty from growing and lets you claim your deductions. A return that was never filed cannot be amended.
State deadlines
States set their own deadlines, and many charge annual taxes regardless of income. California charges LLCs $800 every year. Delaware LLCs pay their annual tax by June 1, and Delaware corporations file their annual report and franchise tax by March 1. See our guide to annual compliance requirements for the state side.
How MyUSAService helps
MyUSAService prepares and files U.S. returns for companies owned from abroad: from $951 for a single-member LLC or a C corporation, $951 plus $150 for each Schedule K-1 for a partnership. The yearly renewal for a single-member LLC includes Form 5472, the pro forma Form 1120, the registered agent and the state fee. Prices as of September 2026.
Frequently asked questions
When is Form 5472 due?
With the pro forma Form 1120, by the 15th day of the 4th month after the end of the tax year: April 15 for a calendar-year LLC. It can be extended with Form 7004.
When is Form 1065 due?
By the 15th day of the 3rd month after the end of the tax year: March 15 for a calendar-year partnership, moved to the next business day when it falls on a weekend or holiday.
Does an extension give me more time to pay?
No. Form 7004 extends the time to file. Tax due must be paid by the original due date to avoid interest and the failure-to-pay penalty.
When do non-residents file Form 1040-NR?
By June 15 if you did not receive U.S. wages subject to withholding, by April 15 if you did.
When are corporate estimated taxes due?
On the 15th day of the 4th, 6th, 9th and 12th months of the tax year, if the corporation expects to owe $500 or more.
Unsure which IRS deadlines apply to you?
Talk for 30 minutes, free of charge, with a MyUSAService consultant.
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Sources
- IRS, Instructions for Form 1065
- IRS, Instructions for Form 1120-S
- IRS, Instructions for Form 1120
- IRS, Instructions for Form 5472
- IRS, Instructions for Form 1040-NR
- IRS, Instructions for Form 7004
- IRS, When are quarterly estimated tax payments due?
- IRS, Failure to file penalty
- IRS, Failure to pay penalty
- IRS, Filing past due tax returns
First published April 23, 2025. This article is general information, not tax advice for your situation. U.S. tax return filing | Book a free call
Annual Compliance Requirements for U.S. LLCs & Corporations
Avoid IRS Penalties and Audits: A Guide for Owners Abroad
Guide to U.S. Business Taxes for Non-Resident Owners
Inactive LLC Tax Return: Do You File With Zero Revenue?