The October 15 Deadline: What Foreign-Owned LLC Owners Who Filed an Extension Must Not Forget

If you own a US LLC from outside the United States and filed for an extension this spring, your filing is not finished — it is paused. The single most common mistake we see in the summer is an owner who filed Form 7004 in April, felt relieved, and then mentally closed the file. The extension simply moved your deadline to October 15. For calendar-year filers, that wall is now in clear view, and missing it carries the same $25,000 penalty as never filing at all.

This article explains what your spring extension actually bought you, the rules that trip up non-resident owners, and how to file correctly before the October deadline.

First, Who This Applies To

A US LLC owned by a non-US person and treated as a "disregarded entity" (the default for a single-member LLC that has not elected to be taxed as a corporation) has a specific federal obligation. Under section 6038A regulations, the LLC must file a pro forma Form 1120 with Form 5472 attached — even if the company had no US tax to pay and even if it made no profit. This is an information return, not an income tax bill, but the IRS treats a missed filing very seriously.

If you filed Form 7004 by your original due date, you obtained an automatic six-month extension. For a calendar-year LLC, that means your deadline moved from April 15 to October 15.

What the Extension Did — and What It Did Not Do

The extension gave you more time to file the forms. That is all. It is worth being precise about three things people misread:

The extension is not automatic just because you meant to file one. You only have until October 15 if Form 7004 was actually submitted by your original due date. If you never filed the extension, your forms were technically due in April, and the right move now is to file as soon as possible rather than wait for October.

The extension does not extend time to pay any tax owed. Most disregarded foreign-owned LLCs owe no US income tax, so this is often moot — but if your structure does generate a US tax liability, interest can still run from the original date.

The extension does not change how you file. The special mailing and fax rules below still apply.

The Mail-or-Fax Rule That Surprises People

You cannot simply e-file Form 5472 the way you might a personal return. A foreign-owned disregarded entity must send the pro forma Form 1120 with Form 5472 attached to a dedicated IRS unit, by one of only two methods:

By fax (300 DPI or higher) to 855-887-7737, or by mail to: Internal Revenue Service, 1973 Rulon White Blvd, M/S 6112, Attn: PIN Unit, Ogden, UT 84201.

Two practical details matter here. Write "Foreign-owned U.S. DE" across the top of the Form 1120. And on the pro forma Form 1120 itself, the IRS only requires the name and address of the entity plus items B and E on the first page — you are not completing a full corporate tax return.

If you live abroad and rely on postal mail, fax is usually the safer choice for a hard October deadline. Keep the fax confirmation page; it is your evidence of timely filing.

The Penalty Is Not a Typo

The IRS assesses a $25,000 penalty on any reporting entity that fails to file Form 5472 when due and in the manner prescribed. The same penalty applies to a substantially incomplete form. And it does not stop there: if the failure continues for more than 90 days after the IRS notifies you, an additional $25,000 applies for each 30-day period (or part of one) that the failure continues after that 90-day window.

In other words, a form that takes an experienced preparer under an hour can become a five-figure problem purely from inaction. This is why the October date deserves a place on your calendar now, in June, rather than a scramble in the first week of October.

A Simple Plan Before October 15

Confirm whether you actually filed Form 7004 in the spring. If you did, your deadline is October 15; if you did not, file now. Gather the figures you need for Form 5472 — chiefly the "reportable transactions" between you and your LLC during the year, such as capital you contributed and money you withdrew. Prepare the pro forma Form 1120 with only the required fields. Then fax the package to the dedicated number well before the deadline and save the confirmation.

The extension was the easy part. Finishing the filing — correctly, and on time — is what actually protects you from the penalty.

Have Questions About Your Own Situation?

Every ownership structure is a little different, and the rules around foreign-owned LLCs reward getting the details right. If you would like to talk yours through with the MP Partner experts team — no pressure, no hard sell, just clear answers — we are happy to help.

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