What is a pro forma Form 1120? (And why your LLC has to file one)

A pro forma Form 1120 is a mostly-blank US corporate tax return that serves as the mandatory cover sheet for Form 5472 when filed by a foreign-owned disregarded LLC. Foreign-owned single-member LLCs cannot file Form 5472 on its own — the IRS requires the two documents to be submitted together as one package (IRS, Form 5472 instructions). Sending Form 5472 without the attached Form 1120, or vice versa, is treated as a failure to file and triggers the $25,000 penalty.

The word "pro forma" means "as a formality." Most of the 1120 is left blank — you're not computing corporate income tax. You're just providing the entity identifier fields the IRS needs to associate the Form 5472 with the right LLC.

Why does a disregarded LLC have to file Form 1120?

A single-member LLC is a "disregarded entity" by default — it's invisible for income tax purposes, with all income flowing through to its owner. But Form 5472 was originally designed for US corporations, not for disregarded entities. When the IRS extended Form 5472 to cover foreign- owned disregarded LLCs in 2017, they needed a vehicle to attach it to. Form 1120 was the closest fit. The "pro forma" filing is a workaround in the regulations, not an indication that your LLC owes corporate income tax.

What you actually fill in on the pro forma 1120

For a foreign-owned disregarded LLC, you complete only these fields on page 1 of Form 1120:

• Name: the LLC's legal name, exactly as on the EIN registration.
• Address: the LLC's mailing address (registered agent address is fine).
• EIN: the LLC's employer identification number.
• Date incorporated: the LLC's formation date.
• Total assets at year end: the LLC's total assets (bank balance + any other assets) as of December 31 in whole dollars.
• Mark at the top: write "Foreign-Owned U.S. DE" at the very top of the first page. The IRS instructions require this notation to indicate the form is being filed solely as a Form 5472 attachment.

Everything else on Form 1120 — all income, deductions, credits, tax calculation lines — is left blank. Do not enter zeros on blank lines. Do not complete pages 2–6.

Common mistakes with the pro forma 1120

Filing Form 5472 without the 1120 (or vice versa)

Both documents must be in the same package, faxed together to the Ogden PIN Unit. Separate submissions don't count as a complete filing.

Completing the income/tax sections

Disregarded LLCs don't owe corporate income tax. Leaving those sections blank is correct. Entering zeros as if they were income-tax items creates confusion and may trigger IRS correspondence.

Wrong total assets figure

Total assets should be the LLC's balance sheet total as of December 31 — primarily the ending bank balance, plus any equipment, receivables, or other assets the LLC owns. Don't use personal assets.

Using the wrong address

Use the LLC's mailing address (usually its registered agent's address). Don't use your personal foreign address — this isn't the foreign owner's return.

The filing package

The complete package faxed to the IRS looks like:

1. Pro forma Form 1120 (just the identifying fields, marked "Foreign-Owned U.S. DE")
2. Form 5472 (all required parts completed, including Part IV reportable transactions)
3. Part V supporting statement listing individual reportable transactions in detail
4. For late filings (DIIRSP): DIIRSP cover letter + reasonable-cause statement

Snapfile generates and packages all of these from your 12-question wizard responses. Start a filing for $89 — fax to Ogden included.

Conservative summary

• Pro forma Form 1120 is a mandatory cover sheet for Form 5472 — always file both together.
• Fill in only: name, address, EIN, formation date, total assets. Write "Foreign-Owned U.S. DE" at the top. Leave everything else blank.
• You are not filing a corporate tax return and do not owe corporate income tax on this form.
• The penalty for missing the combined package is $25,000 — same as if you filed nothing at all.