Extended C Corporation Return: What Is Due October 15

Are Form 1120 and Form 5472 due October 15 after Form 7004?

Yes, for a calendar-year US C corporation with a valid Form 7004 extension, Form 1120 is due October 15. Attach each required Form 5472 to that return by the same date. A fiscal-year corporation counts from its own year-end, so October 15 may not apply (Form 7004 instructions; Form 5472 instructions).

These are federal dates. A corporation formed in Delaware has separate state obligations. Confirm whether Form 5472 is required from the foreign-owned C corporation filing guide.

Did Form 7004 extend Form 5472 too?

Yes. Form 5472 is an attachment to the reporting corporation's income tax return, and the IRS says it is due with that return, including extensions (Form 5472 instructions). A corporation filing Form 1120 does not request a separate Form 5472 extension.

Check that Form 7004 identified Form 1120 on Part I, line 1, and was properly filed. The IRS says a proper request automatically grants the available filing extension and usually sends a notice only if it disallows the request (Form 7004 instructions). Keep the request and filing proof. The IRS treats a substantially incomplete Form 5472 as a failure to file (Form 5472 instructions).

Can we file Form 7004 after April 15?

Generally, no. A calendar-year C corporation must file Form 7004 by the ordinary Form 1120 due date, April 15. Filing Form 7004 after that date does not create an October extension (Form 1120 instructions; Form 7004 instructions).

One exception is a domestic corporation that qualifies for the books-abroad rule below: its automatic June 15 date can give it until then to request an additional filing extension. A domestic corporation whose principal income comes from US territories can also qualify (Form 7004 instructions). If no later date applies, file the overdue Form 1120 with any required Form 5472 promptly. If earlier years or a penalty notice are involved, see missed foreign-owner filings.

Did the extension give us until October 15 to pay tax?

No. Form 7004 extends filing, not payment. For an ordinary calendar-year C corporation, unpaid income tax was generally due April 15, even if Form 1120 is due October 15. The corporate extension regulation requires remittance of properly estimated unpaid tax to obtain the extension; filing the form alone may not secure October 15 if the corporation paid nothing (Form 7004 instructions; Treasury regulation 1.6081-3). Interest runs on unpaid tax from the payment due date. A late-payment penalty generally starts at 0.5% of unpaid tax for each month or part month (Form 1120 instructions). The payment exception and full calculation are in late-filing and payment penalties.

Do books kept outside the US change the dates?

Sometimes. A domestic corporation that both conducts its business and keeps its books and records outside the United States and Puerto Rico gets an automatic extension to June 15 to file and pay for a calendar year. Foreign ownership or an owner living abroad, by itself, does not establish those conditions (Treasury regulation 1.6081-5). Payment by June 15 can avoid a late-payment penalty, but interest generally accrues on tax paid after April 15 (Internal Revenue Code, sections 6651 and 6601).

To file later, submit Form 7004 by June 15 and check Part II, line 4. For a C corporation, the additional filing period is four months, ending October 15; it does not extend payment beyond June 15. The regulation also requires a statement with the return explaining why the corporation qualified for the automatic extension (Form 7004 instructions; Treasury regulation 1.6081-5). Gather records showing where the business operated and its books were kept before using this rule.

What if Form 1120 is late but total tax is zero?

If the corporation's correct total tax is zero, a late Form 1120 generally has no income-tax late-filing penalty. A zero incorrectly entered on a return does not establish that result.

The ordinary Form 1120 charge uses tax unpaid at the original payment deadline. For a calendar-year return more than 60 days late, the minimum is the lesser of $535 or tax unpaid at that deadline. It is zero if all tax was paid on time (Internal Revenue Code, section 6651; IRS Revenue Procedure 2025-32). For tax owed, see late-filing and payment penalties.

What does a late or incomplete Form 5472 cost?

A required Form 5472 that is missing, late, or substantially incomplete can trigger a separate $25,000 penalty, regardless of whether the corporation owes income tax. Failure to keep required records can trigger it too (Form 5472 instructions).

If the failure continues more than 90 days after the IRS notifies the corporation, an additional $25,000 applies for each related party for each 30-day period or part period that follows. File the missing information promptly; reasonable cause and penalty notices require a separate review. Keep related-party transaction records so the attachment can be completed accurately.

Does a weekend or holiday move October 15?

Yes. If a federal filing or payment deadline falls on a Saturday, Sunday, or legal holiday, the act is timely on the next day that is none of those. The rule includes an authorized extended deadline (Internal Revenue Code, section 7503). Check the actual calendar before filing; a foreign holiday does not automatically move a US federal due date.

Example

Illustrative amounts are in US dollars. Each company has a calendar tax year and one required Form 5472.

Extension filed on time; no tax due

A Delaware C corporation owned by a founder in India files Form 7004 on April 10. It owes $0 income tax and files Form 1120 by October 15. If it leaves off Form 5472 or files it substantially incomplete, the corporation faces the separate $25,000 Form 5472 penalty even though Form 1120 was on time.

No Form 7004 filed

The same corporation never files Form 7004. Assuming the books-abroad rule does not apply, its return was due April 15. It files Form 1120 and Form 5472 now. With $0 tax due, the ordinary Form 1120 late-filing penalty is $0, but the late Form 5472 can still draw $25,000. It addresses any penalty notice under the missed-filings guide.

Extension filed, but tax unpaid

The corporation files Form 7004 but pays none of its $10,000 tax by April 15. Interest and a late-payment penalty generally start then. At 0.5% per month or part month, the first month costs $50. Because it paid none of the properly estimated tax, it must check whether its filing extension is valid. If not, filing after April 15 is late, even before October 15. The late-filing rate starts at 5% per month or part month: $500 for the first month on $10,000, reduced when the late-payment penalty applies for the same month, and capped at 25%.

Different for you?

• You need to decide which forms to attach: see foreign-owned C corporation filing.
• You must sign, submit, or pay from abroad: see filing a corporate return from abroad.
• You have missed years or received a Form 5472 penalty notice: see missed foreign-owner filings.
• You owe tax and need the penalty calculation or relief rules: see late-filing and payment penalties.
• You are preparing the return before the deadline: gather books, payment records, Form 7004 proof, and related-party transactions using the preparer checklist, or seek corporate tax help.
• You also have a Delaware annual report or franchise tax bill: see Delaware franchise tax; its deadline is separate.