Filing Form 5472 with the Pro Forma 1120: The Complete Process
Updated June 2026 · Reviewed by a Form 5472 specialist
Updated June 2026 · Reviewed by a Form 5472 specialist
The short answer
Key takeaways
The process has seven steps: obtain the EIN, build a transaction ledger, complete the pro forma 1120 shell, complete Form 5472 Parts I–VI, assemble the package with the 1120 on top, mail or fax it to Austin, TX, and keep proof of filing.
Form 5472 and the pro forma Form 1120 are not two separate filings — they are one package. The 1120 is the cover return required by the regulations; Form 5472 is the disclosure attached behind it. Understanding this relationship is the key to filing correctly: you never file one without the other.
This process applies to a foreign-owned disregarded entity for tax years beginning on or after January 1, 2017, under Treasury Decision 9796 and IRC section 6038A. Below is the complete end-to-end sequence.
| Step | What you do | Output |
|---|---|---|
| 1 | Obtain the LLC's EIN | 9-digit EIN |
| 2 | Build a reportable-transaction ledger | Money-in / money-out record |
| 3 | Complete the pro forma 1120 shell | Labeled cover return |
| 4 | Complete Form 5472 Parts I–VI | Completed disclosure |
| 5 | Assemble: 1120 on top, 5472 behind | One stapled package |
| 6 | Mail or fax to Austin, TX | Submitted filing |
| 7 | Keep dated proof | Certified mail or fax confirmation |
Source: IRS Instructions for Form 5472; IRC §6038A. Verified June 2026.
Because IRS regulations require Form 5472 to be attached to an income tax return. A disregarded entity's only available return is the pro forma Form 1120, so the two must be filed as one package. Form 5472 cannot be mailed alone.
The pairing is not a choice — it is built into how section 6038Aworks. The statute ties Form 5472 to the filing of a corporate income tax return. When the 2017 regulations made a foreign-owned disregarded entity a “reporting corporation,” they triggered the requirement to file a Form 1120 as the carrier for Form 5472 — even though the entity owes no corporate tax.
So the pro forma 1120 exists onlyto satisfy the “attach to a return” requirement. Form 5472 is the substance; the pro forma 1120 is the envelope. Mailing the 5472 without the envelope leaves the IRS with an attachment to nothing, which it can treat as an invalid — and therefore unfiled — return.
Place the pro forma Form 1120 on top as the cover return and staple the completed Form 5472 behind it. For more than one related foreign party, attach a separate Form 5472 for each to the same single pro forma 1120.
Assembly is simple but order matters. The pro forma 1120 goes on top — it is the cover return the IRS logs first. The completed Form 5472 is stapled directly behind it. Together they form one filing that travels as a unit.
| Position | Document | State |
|---|---|---|
| Top | Pro forma Form 1120 | ID block complete, 'Foreign-owned U.S. DE' across top, tax lines blank |
| Behind it | Form 5472 (one per related party) | Parts I, II, III, V, VI complete |
| Optional | Supporting schedules | Only if the form requires them |
Source: IRS Instructions for Form 5472. Verified June 2026.
A typical single-owner LLC files one pro forma 1120 with one Form 5472. Only when the LLC transacted with multiple related foreign parties do you add additional Forms 5472 — all attached to the same single pro forma 1120.
Mail the combined package to P.O. Box 149342, Austin, TX 78714-9342, or fax it to 855-887-7737. A foreign-owned disregarded entity cannot e-file. Keep the certified-mail receipt or fax confirmation as proof.
The combined package follows the foreign-owned disregarded entity filing rules: mail or fax only. There is no e-file path, no online portal, and no exception. Faxing returns an instant confirmation; mailing requires certified mail to establish the filing date.
| Method | Where | Proof to keep |
|---|---|---|
| Internal Revenue Service, P.O. Box 149342, Austin, TX 78714-9342 | Certified-mail receipt | |
| Fax | 855-887-7737 | Fax transmission confirmation |
Source: IRS Instructions for Form 5472, filing instructions for foreign-owned U.S. DEs. Verified June 2026.
Both are due April 15 for the prior calendar year as one package. Filing Form 7004 by April 15 extends the deadline to October 15. The 2025 tax year package is due April 15, 2026.
Because they are one filing, Form 5472 and the pro forma 1120 share a single deadline: April 15 for a calendar-year entity. A six-month extension to October 15 is available by filing Form 7004 on or before April 15.
| Tax year | Standard deadline | Extended (with Form 7004) |
|---|---|---|
| 2024 | April 15, 2025 | October 15, 2025 |
| 2025 | April 15, 2026 | October 15, 2026 |
| 2026 | April 15, 2027 | October 15, 2027 |
Source: IRS Instructions for Form 1120 / Form 7004. Verified June 2026.
Since the package carries no tax, the extension only moves the filing deadline — there is no payment to extend. File Form 7004 by April 15 to claim the extra six months.
The penalty is $25,000 per Form 5472, per year, with no cap and no statute of limitations. An incomplete package — missing the pro forma 1120, the EIN, or the label — can be treated as a failure to file and trigger the full penalty.
The $25,000 penalty attaches to Form 5472, but a defective package puts it at risk just as surely as not filing at all. If the IRS treats the filing as substantially incomplete — for example, because the pro forma 1120 was omitted, the EIN was missing, or Form 5472 was not attached — it is the same as a failure to file under section 6038A.
The penalty also compounds: after a 90-day IRS notice goes unanswered, an additional $25,000applies for each 30-day period the failure continues. Filing a complete, correct package on time is the only reliable way to avoid all of this.
Form 5472 and the pro forma 1120, prepared, assembled, reviewed, and filed together for a flat $299.