Pro Forma 1120 Explained: Why Every Foreign LLC Must File It

“Pro forma” is Latin for “as a matter of form.” That is exactly what this return is: a placeholder. Form 1120 is normally the US Corporation Income Tax Return, where a real corporation reports its revenue, deductions, and tax. But a foreign-owned single-member LLC is a disregarded entity — it is not a corporation and owes no entity-level income tax. So when the IRS requires it to attach Form 5472, the LLC files an empty 1120 as the vehicle.

Think of the pro forma 1120 as an envelope and Form 5472 as the letter inside. The IRS systems are built to receive Form 5472 stapled to a 1120, so the envelope has to exist even though it carries no tax numbers. The related pro forma 1120 page walks through the blank fields field by field.

Before 2017, a single-member LLC owned by a non-US person was invisible to the IRS — disregarded for all federal purposes and not required to file anything. That changed when the Treasury issued T.D. 9796, which carved out a narrow rule: a foreign-owned US disregarded entity is treated as a corporation solely so it can be made to report under IRC §6038A. This was an information-reporting fix, not a tax change.

The practical result is the two-part filing every foreign founder now does: Form 5472 to disclose transactions, and a pro forma 1120 to carry it. The LLC still pays no US corporate income tax and keeps its disregarded status for everything else. For how the two forms fit together, see filing Form 5472 with the pro forma 1120.

This is the part that confuses beginners the most: a tax form with 30 numbered lines, almost all left blank. That is correct and intentional. The IRS instructions for a foreign-owned disregarded entity say to enter only the entity's identifying information and to write the note across the top margin. No revenue, no cost of goods, no taxable income, no signature on the tax-computation lines.

The real work is on Form 5472 itself, not the 1120. If you do not yet have an EIN to put in the heading box, you cannot file — the how to file Form 5472 guide covers getting one first.

New founders often assume that because they made no sales, they owe nothing and file nothing. That is the most expensive misunderstanding in this area. The trigger is a reportable transaction between the LLC and its foreign owner, and that includes the very money used to form and capitalize the company. When you wired your own funds into the LLC's bank account, that capital contribution is reportable.

Common transactions that trigger the filing

Almost any movement of money or value between you and your LLC counts: an initial capital contribution, paying the formation fee from your personal account, lending the LLC money, taking a distribution, or reimbursing yourself. Because at least one of these happens to nearly every new LLC, virtually every foreign-owned SMLLC has a reportable transaction, so almost all must file. Confirm your situation against the pro forma 1120 page.

There is no electronic option for a disregarded entity's pro forma 1120, and no software can submit it for you. Print the two forms, staple Form 5472 to the 1120, and transmit the package by one of the two channels below before the deadline. Always keep proof — a certified-mail receipt or the fax transmission confirmation — because there is no IRS acknowledgment for this filing.

For a complete walkthrough including assembly order, see how to file Form 5472.

The due date is the 15th day of the 4th month after the tax year ends — April 15 for the standard calendar year. Because a disregarded entity has no entity-level tax to pay, the Form 7004 extension is a pure filing extension; there is no payment to accompany it. Missing the original date without an extension is what exposes you to the penalty.

If you file Form 5472 without the pro forma 1120, the IRS may treat it as not filed because the form had no return to attach to — and the same $25,000 penalty can apply. Because §6501(c)(8) leaves an unfiled information return open indefinitely, a year you missed long ago can still be assessed today. This is one of the harshest information-return penalties in the tax code.

We prepare and file the package correctly so this never comes up; we do not offer penalty-abatement or IRS representation. The cheapest insurance is to file on time. Compare the cost on the pricing page.

Founders often bundle these in their heads, but they answer to two different agencies. Beneficial Ownership Information (BOI) is a FinCEN anti-money-laundering filing; the pro forma 1120 plus Form 5472 is an IRS tax information return. As of FinCEN's March 2025 interim final rule, a US-formed LLC owned by a non-US person does not file BOI — that obligation now falls only on foreign reporting companies.

So even if you have heard you are off the hook for BOI, your Form 5472 and pro forma 1120 duty is untouched. One does not cancel the other. The apply page starts the Form 5472 filing that still applies to you.