Form 5472 is the information return that discloses reportable transactions between a foreign-owned US LLC and its related parties. The pro forma Form 1120 is the cover document that a foreign-owned disregarded entity attaches Form 5472 to when submitting it to the IRS. Most foreign owners need both — filing one without the other results in an incomplete submission, which the IRS treats the same as not filing at all.
Few Form 5472 questions cause as much confusion as this one: if Form 5472 is the form foreign owners actually need, why does a pro forma Form 1120 keep showing up alongside it? The short answer is that these two documents serve entirely different purposes, but a foreign-owned US LLC with reportable transactions generally needs to submit both together.
Mixing them up, or assuming one replaces the other, is one of the more common — and entirely avoidable — mistakes foreign owners make. Getting the relationship between these two forms right matters, because an incomplete filing can trigger the same $25,000 penalty as not filing at all.
This guide breaks down what each form actually does, walks through a real-world scenario showing why both are typically required, and covers the timeline and filing requirements you need to know for each.
What Is Form 5472, and What Does It Report?
Form 5472 is an IRS information return. Its job is to disclose reportable transactions between a US reporting entity — in this case, a foreign-owned US LLC — and its foreign related parties, including the owner.
Reportable transactions aren't limited to obvious line items like service fees or loan proceeds. They also commonly include:
- Capital contributions made to the LLC
- Distributions or withdrawals taken out
- Formation costs paid personally by the owner
- Registered agent, banking, or software fees paid out-of-pocket
- Personal expenses charged to the LLC's account
Form 5472 exists so the IRS can see the financial relationship between a US entity and the non-US person or entity that owns it. It doesn't calculate tax owed. It discloses activity.
What Is the Pro Forma Form 1120, and Why Does It Exist?
Form 1120 is normally the standard US corporate income tax return. A foreign-owned single-member LLC, however, is generally treated as a disregarded entity for US tax purposes — meaning it doesn't otherwise file a full corporate return.
That creates a gap: Form 5472 needs a tax return to attach to, but the disregarded entity doesn't file one. The solution is the pro forma Form 1120 — an abbreviated version of the form that exists specifically to serve as a cover document for Form 5472. It isn't used to report income or calculate tax. Its purpose is procedural: it gives Form 5472 a return to attach to so the IRS can process the filing correctly.
Choose to treat Form 5472 and the pro forma Form 1120 as a package, not two separate filings, if your LLC is a foreign-owned disregarded entity. For most foreign owners, that's exactly the structure they're working with.
A Real-World Scenario: Why Both Forms Are Usually Required
Consider a foreign owner who forms a single-member US LLC to run an online consulting business. During the first year, the owner contributes $5,000 to open the LLC's bank account and pays a $300 registered agent fee from a personal credit card. The LLC generates no US-source income that year.
The owner assumes that because there's no income and no formal tax return to file, there's nothing to submit. This is a mistake. The $5,000 contribution and the $300 fee paid personally are both reportable transactions. That means Form 5472 is required — and because the LLC is a foreign-owned disregarded entity, the pro forma Form 1120 must be attached as the cover document when the filing is submitted.
In this scenario, filing Form 5472 alone, without the pro forma Form 1120, would leave the IRS unable to process the return under its normal structure. The reverse is also true: there's no reason to file a pro forma Form 1120 on its own, since its only function here is to carry Form 5472 to the IRS. Choose to confirm both pieces are included before submission if any reportable transactions occurred during the year — even in a year with zero revenue.
Timeline and Filing Requirements for Each Form
Form 5472 and the pro forma Form 1120 share a single deadline rather than operating on separate timelines. Both are generally due by April 15 following the end of the tax year, and both are submitted together as one package.
Form 5472 filing requirements:
- Applies when a foreign-owned US LLC has reportable transactions with its owner or related parties
- Requires detailed disclosure of each transaction, including the nature, amount, and terms
- Due April 15 following the end of the tax year, or by the extended deadline if a timely extension was filed
Pro forma Form 1120 filing requirements:
- Required as the cover document when a foreign-owned disregarded entity submits Form 5472
- Does not report income or calculate a tax liability for the disregarded LLC itself
- Filed alongside Form 5472, not on a separate schedule
- Must include paid preparer information, including PTIN, when a tax professional prepares the filing
An extension can push the April 15 deadline back for both forms, but it must be filed properly before the original due date — not after it has already passed. Missing that distinction is one of the more common ways foreign owners accidentally miss the deadline entirely.
Getting the Form 5472 and Pro Forma Form 1120 Package Right
Form 5472 and the pro forma Form 1120 aren't competing requirements or alternative paths to the same outcome. They're two parts of one filing package, and for a foreign-owned disregarded entity with reportable transactions, both are typically necessary. Submitting one without the other generally results in an incomplete filing, and the IRS treats an incomplete filing the same as no filing at all — which means the $25,000 penalty exposure remains.
If you're unsure whether your LLC's transactions this year require both forms, or you want to make sure a prior-year filing included the correct pro forma Form 1120 attachment, getting a professional review now is far less costly than correcting a rejected filing later.
5472forYOU prepares both Form 5472 and the pro forma Form 1120 together for foreign-owned US LLCs, with filings reviewed by Michal Zacik, a US tax professional with more than 10 years of corporate tax experience and over 7 years focused specifically on nonresident taxation (PTIN: P03281868). Standard Filing starts at $199, with Expert Filing available at $299 for owners who want dedicated case review. There's no upfront payment required, and reasonable cause statements are included at no additional charge for eligible late filings.
Get Your Form 5472 and Pro Forma Form 1120 Filed Correctly →
