Pro Forma 1120 Instructions: How to Complete It for Form 5472
Updated June 2026 · Reviewed by a Form 5472 specialist
Updated June 2026 · Reviewed by a Form 5472 specialist
The short answer
Key takeaways
Completing a pro forma 1120 takes seven steps: download the form, label it “Foreign-owned U.S. DE,” fill in the name and address, enter the EIN and formation date, leave all tax lines blank, attach Form 5472, and mail or fax the package.
A pro forma Form 1120 is the easiest tax form most founders will ever complete — precisely because almost all of it stays empty. The 1120 is normally a dense corporate return, but a foreign-owned disregarded entity uses it as a shell: a cover sheet whose only job is to carry Form 5472 to the IRS. There is no income to report and no tax to compute.
The instructions below apply to a foreign-owned disregarded entity filing for tax years beginning on or after January 1, 2017 under Treasury Decision 9796. Follow them in order.
| Step | What you do | Output |
|---|---|---|
| 1 | Download the current Form 1120 from IRS.gov | Blank current-revision form |
| 2 | Write 'Foreign-owned U.S. DE' across the top | Labeled pro forma return |
| 3 | Complete the name and address block | Identified entity |
| 4 | Enter EIN (box B) and formation date (box C) | Logged filing identity |
| 5 | Leave all income and tax lines blank | Shell return, no tax |
| 6 | Attach Form 5472 behind it | One stapled package |
| 7 | Mail or fax and keep proof | Submitted filing |
Source: IRS Instructions for Form 5472 and Form 1120. Verified June 2026.
Write “Foreign-owned U.S. DE” across the top of page 1. This label tells the IRS the form is a pro forma return filed by a foreign-owned disregarded entity to carry Form 5472 — not a regular corporate income tax return.
The “Foreign-owned U.S. DE”label is the single most important annotation on the form. “DE” stands for “disregarded entity.” Without this label, an IRS processor might treat a blank 1120 as an error or an incomplete corporate return. With it, the IRS recognizes the form for what it is: the required pro forma container for Form 5472.
Write it clearly across the top margin of page 1, above the form's title. This is directly per the IRS instructions for foreign-owned disregarded entities, which direct filers to enter this notation.
Only the header lines: the name and address block, box B (EIN), and box C (date and state of formation). Every income line (1–11), deduction line (12–29), and tax and payment line (30–37) stays blank for a disregarded entity.
The discipline of the pro forma 1120 is restraint. The temptation is to fill in numbers; the correct move is to leave them blank. Here is exactly what to complete and what to skip.
| Form 1120 line / box | Action | Reason |
|---|---|---|
| Top margin | Write 'Foreign-owned U.S. DE' | Required label for a DE filing |
| Name and address | Complete | Identifies the reporting entity |
| Box A (consolidated/etc.) | Leave blank | Not applicable to a DE |
| Box B — EIN | Complete | Mandatory identifier |
| Box C — date incorporated | Complete | Date and state of formation |
| Box D — total assets | Optional; per books if reported | No tax effect |
| Lines 1–11 (income) | Leave blank | DE reports no entity income |
| Lines 12–29 (deductions) | Leave blank | No deductions computed |
| Lines 30–37 (tax & payments) | Leave blank | No entity-level tax due |
| Signature | Sign and date | An authorized person signs |
Source: IRS Instructions for Form 5472; Instructions for Form 1120. Verified June 2026.
Some filers enter the entity's total assets in box D from the LLC's books; it has no tax effect either way. The income and tax lines, however, must always stay blank — entering income figures on a disregarded entity's pro forma 1120 is a common and avoidable error.
Staple the completed Form 5472 behind the pro forma 1120 so the two travel as one package. If the LLC had more than one related foreign party, attach a separate Form 5472 for each to the same single pro forma 1120.
The pro forma 1120 goes on top; the completed Form 5472 is attached behind it. Together they form a single filing. The 1120 without the 5472 is meaningless, and the 5472 without the 1120 is an invalid filing — they must always travel together.
A typical single-owner LLC files one pro forma 1120 with one Form 5472. If the LLC transacted with more than one related foreign party — for example, both the owner and a second foreign company the owner controls — file a separate Form 5472 for each related party, all attached to the same single pro forma 1120.
Mail the 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 dated proof of timely filing.
Once the pro forma 1120 is complete and Form 5472 is attached, the package goes to the IRS by mail or fax only — there is no e-file path. Faxing gives an instant confirmation; mailing requires certified mail for proof.
| 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.
The top mistakes are: omitting the “Foreign-owned U.S. DE” label, leaving off the EIN, entering income or tax figures that should be blank, forgetting to attach Form 5472, and trying to e-file. Each can trigger the $25,000 penalty.
| Mistake | Why it happens | How to avoid it |
|---|---|---|
| No 'Foreign-owned U.S. DE' label | Filer doesn't know it's required | Write it across the top of page 1 |
| Missing EIN | EIN not obtained in time | Apply on Form SS-4 early, by fax |
| Entering income/tax figures | Filer treats it like a real 1120 | Leave all income and tax lines blank |
| Form 5472 not attached | Filer mails the 1120 alone | Always staple Form 5472 behind it |
| Trying to e-file | Software offers e-file for 1120 | Mail or fax only for a DE |
Source: form5472.tax filing experience; IRS Instructions for Form 5472. Verified June 2026.
Each error can cause the IRS to treat the filing as substantially incomplete — equivalent to not filing — and expose you to the $25,000 penalty. This is why many founders pay a flat $299 for a specialist to complete the pro forma 1120 and Form 5472 correctly rather than risk a costly mistake.
We complete the pro forma Form 1120 and Form 5472, review them, and file the package correctly for a flat $299.