The pro-forma Form 1120 for foreign-owned LLCs: line by line

A foreign-owned single-member US LLC is a "disregarded entity" for federal income tax — it is ignored, and its income (if any) is reported on the owner’s personal or corporate return wherever the owner is taxed. Logically, then, the LLC files no US income tax return. That logic was correct until 2017. Treasury regulations under Section 6038A changed it.

Since the 2017 tax year, a foreign-owned disregarded LLC must file Form 5472 to disclose related-party transactions. Form 5472 cannot be filed standalone — it must be attached to Form 1120, the US C-Corporation income tax return. The result is a strange artifact: a corporate income tax return with no corporate income, filed by an entity that is not a corporation. The IRS calls this the "pro-forma" Form 1120. This is the breakdown of what goes on it.

The header label that is not in the printed instructions

IRS Notice 2017-69 instructs the filer to write "Foreign-Owned U.S. DE" across the top of Form 1120 in plain text — typed or hand-written, in a clearly visible position above the form title. This label tells the IRS that the 1120 is a pro-forma return for a disregarded entity, not a full corporate return.

The label appears in Notice 2017-69 but not in the printed Form 1120 instructions or on the form itself. Filers who use a tax-software template typically omit it. The IRS will accept a filing without the label, but the absence increases the chance of the return being routed to corporate-income processing, where the missing income lines look like an incomplete filing.

Which fields are filled (and which stay blank)

Of the ~40 lines on Form 1120 page 1, six are filled for a disregarded LLC pro-forma. The rest stay blank. This is the complete list:

• Box A through Box D in the heading: only Box A ("Check applicable boxes") and the relevant identification fields are completed.
• Entity name and address: the LLC’s legal name and US address. If the LLC has no US address, use the registered agent address.
• EIN: the LLC’s EIN, exactly as issued on the CP 575 confirmation letter.
• Date incorporated: the formation date filed with Delaware.
• Tax year: the LLC’s tax year (almost always January 1 through December 31).
• Income, deductions, tax, and payments sections (lines 1 through 38): all blank. Sign or leave the signature unsigned per the regulations — the disregarded LLC has no separate corporate signer.

The form is intentionally sparse. The IRS is using Form 1120 as a structural carrier for the Form 5472 attachment, not as an income return. Filling income lines for a disregarded LLC is a category error — and triggers IRS correspondence asking for clarification.

How Form 5472 attaches

Form 5472 is a separate schedule that staples to the back of the pro-forma 1120. The 1120 acts as the cover page; the 5472 carries the actual disclosure. If the LLC has reportable transactions with more than one related party, a separate 5472 is filed for each — all attached to the same 1120.

The 5472 is what the IRS actually wants. The 1120 is the wrapper. Without the 1120 wrapper, the 5472 has nowhere to attach — Form 5472 has no standalone filing path for disregarded entities. Without the 5472, the 1120 is an empty corporate return that triggers correspondence.

The mailing address (no e-filing for this case)

Foreign-owned disregarded LLCs cannot currently e-file the pro-forma 1120 + 5472 package through standard tax software channels. The IRS accepts these only by paper or fax, mailed or transmitted to the IRS Ogden, Utah service center.

• Mail: Internal Revenue Service, 1973 Rulon White Blvd., M/S 6112, Attn: PIN Unit, Ogden, UT 84201.
• Fax: +1-855-887-7737. The fax line is monitored during business hours; transmissions outside business hours queue and process the next business day.

Certified-mail proof of delivery is the recommended approach for the paper path. The mailed package can take six to eight weeks to be marked received in the IRS system. Without certified mail proof, the practical absence-of-evidence is treated as a failure to file, and the $25,000 penalty for Form 5472 non-filing begins accruing.

Three common errors that delay processing

1. 1. EIN mismatch. The EIN on the 1120 must match the EIN on every attached 5472 exactly. A single transposed digit creates an unmatched filing in IRS systems.
2. 2. Tax year off by one. Use the calendar year the events occurred in, not the calendar year you file in. A 2025 tax-year return mailed in March 2026 still uses tax year 2025.
3. 3. Missing entity name on attached 5472. The 5472 has its own entity-name field — copy it from the 1120 verbatim, including capitalization and punctuation.

The four-step filing process

1. Print or generate Form 1120. Add the "Foreign-Owned U.S. DE" label across the top.
2. Fill the six entity-identification fields (name, address, EIN, date incorporated, tax year, Box A). Leave income, deduction, tax, and payment lines blank.
3. Complete Form 5472 (one per related party). Attach to the 1120.
4. Mail (with certified delivery confirmation) or fax to IRS Ogden by the deadline — April 15 for calendar-year filers, October 15 with a Form 7004 extension.

How Cherry handles the pro-forma 1120

For Cherry’s foreign-founder cohort, the pro-forma 1120 + 5472 package is one filing on one calendar, but the specific knowledge required to do it cleanly — the Notice 2017-69 header, the empty-income paradox, the fax-versus-mail timing, the EIN consistency check — is exactly the kind of operational tax knowledge a founder should not have to acquire. Cherry generates the package, applies the correct header, ties the 5472 to the 1120 with consistent identifiers, and mails or faxes by the deadline.