Last reviewed October 7, 2026 · By the NYBACS advisory team
Short answer
A pro forma Form 1120 is a mostly blank corporate tax return that serves as the cover document for a foreign-owned disregarded LLC's Form 5472. It is not a tax computation: only the LLC's name, address, EIN (item B) and the return-type checkboxes (item E) are completed, with "Foreign-owned U.S. DE" written across the top. It exists because the IRS needs a return to attach Form 5472 to and to establish a filing date.
Key takeaways
- "Pro forma" means the Form 1120 is a filing vehicle only — no income, deductions or tax are entered on it.
- The IRS instructions limit what is completed to the LLC's name and address plus items B and E on page 1.
- The pro forma return uses the same tax year as the foreign owner's US tax year, or the calendar year if the owner has none.
- The package is faxed or mailed to a dedicated IRS unit in Ogden, Utah; it cannot be e-filed.
- Filing a pro forma Form 1120 does not turn the LLC into a corporation for income tax or create a corporate tax liability.
Why Form 5472 needs a Form 1120 to sit on
Form 5472 was designed for corporations, which always file a Form 1120 to which it can be attached. When the reporting rules were extended to foreign-owned single-member LLCs, those LLCs had no return of their own — a disregarded entity normally files nothing. The IRS solved this by requiring a pro forma Form 1120: a skeleton return whose job is to identify the filer, carry the Form 5472 and fix the date the filing was made.
That date matters. The deadline, the extension and the penalty for not filing are all measured against the Form 1120 due date, so the cover return is what tells the IRS the Form 5472 arrived on time.
Exactly what is completed on the pro forma return
The current Form 5472 instructions say the only information required on the Form 1120 is the DE's name and address and items B and E on the first page. In practice that means:
| Part of Form 1120 | What a foreign-owned DE enters |
|---|---|
| Top margin | "Foreign-owned U.S. DE" written across the top |
| Tax year line | The year being reported (calendar year unless the owner uses a fiscal year for US purposes) |
| Name and address | The LLC's legal name exactly as on its EIN record, and its current mailing address |
| Item B | The LLC's own EIN — not the owner's ITIN or foreign tax number |
| Item E | Initial return, final return, name change or address change, as applicable |
| Income, deduction and tax lines | Left blank |
The Form 5472 itself carries the substance: owner details, country of residence, and the related-party transactions. Practitioners also complete the signature block with an authorized person's signature, because an unsigned return can be treated as not filed.
Getting the tax year and the checkboxes right
Two items cause most avoidable problems.
Tax year. A foreign-owned DE uses the same tax year its owner uses for US tax purposes, and the calendar year if the owner has no US filing requirement. Most foreign individuals therefore file on a calendar-year basis even if their home country uses an April–March or July–June year. A foreign parent company that already files US returns on a fiscal year is the main exception.
Item E checkboxes. Tick Initial return for the first year the LLC exists, even if it was formed in December. Tick Final return in the year the LLC is dissolved, and remember that dissolution costs paid by the owner are themselves reportable in that final year. Name and address changes should also be flagged here so the IRS record is updated; a mismatched name between the return and the EIN record is a common reason for processing problems.
Filing the package: fax, mail and proof
Because foreign-owned DE filings cannot be e-filed, the package is submitted in one of two ways listed in the instructions:
- Fax to the IRS number in the current Form 5472 instructions, at the resolution the instructions specify. Keep the transmission report showing the date, number of pages and successful delivery.
- Mail to the IRS PIN Unit address in Ogden, Utah, given in the instructions. Use a method that produces proof of mailing, such as certified mail or an IRS-designated private delivery service.
If more time is needed, Form 7004 is sent to the same fax number or address by the original due date, using the Form 1120 code. Recheck the instructions every season — the fax number and address have changed before, and a filing sent to an old address is a filing at risk.
What the pro forma return does not do
Filing a pro forma Form 1120 does not elect corporate tax treatment, does not create a corporate income tax bill, and does not mean the IRS now treats the LLC as a C-Corp. The LLC stays disregarded for income tax.
It also does not report the LLC's profit or loss. If the LLC has effectively connected income, that income is reported by the owner — on Form 1040-NR or Form 1120-F — not on the pro forma return. Treating the pro forma Form 1120 as a place to report revenue is a frequent error that confuses the IRS record.
Common mistakes to avoid
- Filling in revenue, expenses or tax lines on the pro forma Form 1120 as if it were a real corporate return.
- Entering the owner's ITIN or foreign tax ID in item B instead of the LLC's own EIN.
- Using the owner's home-country financial year instead of the calendar year when the owner has no US filing requirement.
- Forgetting to tick Initial return in the first year or Final return when the LLC is dissolved.
- Sending the package without the signature block completed or without keeping fax confirmation or proof of mailing.
- Mailing to an IRS service center address copied from an old blog post instead of the address in the current instructions.
Documents and records to prepare
- EIN confirmation letter showing the LLC's exact legal name and EIN
- Current mailing address of the LLC and any change from the prior year
- The owner's US tax year, if the owner files US returns on a fiscal-year basis
- Completed Form 5472 with the related-party transaction totals
- Fax transmission report or proof of mailing from the prior year's filing
NYBACS 360° support
How NYBACS helps
- Prepares the pro forma Form 1120 with only the items the instructions call for, matched exactly to the LLC's EIN record.
- Confirms the correct tax year and initial, final or change checkboxes for your situation.
- Assembles the signed Form 5472 package and coordinates fax or tracked-mail submission with proof retained.
- Files Form 7004 to the dedicated address or fax when records are not ready by the due date.
- Keeps a filing log so next year's package — and any bank or auditor request for proof of filing — is quick to produce.
Frequently Asked Questions
Will the IRS send an acknowledgment that my pro forma Form 1120 was received?
Generally not for paper or fax filings of this kind. Your proof is the fax transmission report or the mailing receipt, which is why keeping it with the filed copy is important.
Can I file a pro forma Form 1120 through ordinary tax software?
Some software can generate the forms for printing, but the filing still has to be faxed or mailed. Do not rely on a software "e-file" button for a foreign-owned DE package.
I own two US LLCs. Do I file one pro forma Form 1120 or two?
Each foreign-owned DE is generally its own reporting entity with its own EIN, so each typically files its own pro forma Form 1120 and Form 5472. Structures with tiered ownership or a common parent should be reviewed before filing.
Does the pro forma Form 1120 need to be filed if the LLC has an extension?
Yes. Form 7004 only moves the due date; the pro forma Form 1120 and Form 5472 must still be filed by the extended deadline.
Who should sign the pro forma return?
An authorized person — typically the sole owner, or an officer of a corporate owner — signs. A paid preparer, if used, completes the preparer section as well.
