Form 1120 vs Pro Forma 1120: Not the Same Filing
TL;DR
Same form number, two different animals. A real Form 1120 is the U.S. corporation income tax return — full financials, taxable income, tax due, e-filed by most corporations. A pro forma 1120 is that form used as a cover page only: name, address, EIN, “foreign-owned U.S. DE” across the top — no income, no tax — existing purely so a Form 5472 has something to be attached to. Foreign-owned single-member LLCs file the pro forma version, by mail or fax.
Why does a disregarded LLC file a “corporate” form at all?
Because Form 5472 cannot be filed on its own — it must ride on a return. A disregarded entity has no return of its own, so the regulations designate a stripped-down 1120 as the carrier. That is the whole story of the pro forma 1120: a filing wrapper, not a tax computation. The LLC does not become a corporation and owes no corporate tax by filing it.
Side by side
| Real Form 1120 | Pro forma 1120 | |
|---|---|---|
| Who files it | C-corporations (and LLCs electing corporate tax) | Foreign-owned disregarded LLCs |
| Contents | Full income, deductions, tax computation | Header info + required notations only |
| Tax due | Computed and payable | None — nothing is computed |
| Form 5472’s role | Attached schedule when applicable | The entire point of the filing |
| How filed | E-filed by most corporations | Mail or fax only |
| Typical preparation | Corporate return engagement | Flat-fee 5472 package |
Where does the confusion cost money?
Two directions, both expensive. Overshooting: a seller asks a generalist firm for “an 1120,” gets quoted a full corporate-return engagement, and pays corporate-return prices for what is a cover page. Undershooting: an LLC that actually elected corporate taxation files only the pro forma shell — leaving a real income tax return unfiled. The filing instructions differ too: the pro forma package goes to a dedicated IRS address by mail or fax, not through the e-file rails a real 1120 uses.
How do I know which one my LLC owes?
Three questions settle it:
- Did the LLC elect corporate taxation (Form 8832)? If yes → real 1120.
- Is it a single-member LLC with a foreign owner and no election? → disregarded entity → pro forma 1120 + Form 5472.
- Multiple members? → different regime entirely — partnership filings, not 1120 at all.
Most cross-border e-commerce sellers with a standard single-member Wyoming or Delaware LLC land squarely in case 2 — the $349 flat-fee filing, not a corporate engagement.
Official references: IRS — About Form 1120 · IRS — Instructions for Form 5472.
This article is general information, not tax or legal advice. Entity classification depends on elections and facts — confirm yours before filing either version.
File it the right way
Laramie Ledger Tax handles foreign-owned LLC filings at flat published prices, prepared and signed by a licensed U.S. tax preparer.
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