Form 5472 and the Pro Forma 1120: What You Actually File

Most coverage of this form stops at the first sentence. The second is the one that turns a bad year into a catastrophic one.

Take that apart.

Failing to file Form 5472 when due and in the manner prescribed carries a $25,000 penalty.[1]Internal Revenue Service, Instructions for Form 5472 (12/2024)

That is the base, and it is charged per reporting corporation, per tax year.

If the failure to file Form 5472 continues for more than 90 days after IRS notification, an additional $25,000 penalty applies.[2]Internal Revenue Service, Instructions for Form 5472 (12/2024)

Read the units on that. It accrues per related party and per 30-day period or part of one, so two related parties and four months of continued failure is not one base penalty. It's a multiple of it.

"Or part of a 30-day period" means a single day into a new period counts as the whole period. There is no proration.

"Corporations file Form 5472 to provide information required under sections 6038A and 6038C when reportable transactions occur with a foreign or domestic related party."

IRS, About Form 5472. Page last reviewed or updated March 30, 2026. Your single-member LLC is disregarded for income tax, which is why people assume there is nothing to file. Disregarded for income tax is not disregarded for information reporting. The LLC is treated as a corporation for this purpose, you are the related party, and money moving between you and it is a reportable transaction.

That last point is the one that catches people. Your own capital contribution is a reportable transaction. So is an expense you paid personally on the company's behalf. Founders who believe they had "no transactions" because they had no customers frequently had several.

You do not prepare a corporate tax return. You prepare a shell for the 5472 to attach to.

"The only information required to be completed on Form 1120 is the name and address of the foreign-owned U.S. DE and items B and E on the first page."

IRS, Instructions for Form 5472.

Name, address, items B and E. Nothing else. Write "Foreign-owned U.S. DE" across the top.

The blankness alarms people into filling in more, which creates a different problem: an 1120 with income figures on it looks like a corporate return and invites correspondence you do not want.

There is no electronic filing path for this. Not through consumer tax software, not through most professional software.

Fax: 855-887-7737

Mail: Internal Revenue Service, 1973 Rulon White Blvd, M/S 6112, Attn: PIN Unit, Ogden, UT 84201

That address is specific to this filing, and the instructions are emphatic:

"Foreign-owned U.S. DEs are required to use the special mailing address...These filers do not use the mailing addresses provided in the Instructions for Form 1120."

IRS, Instructions for Form 5472.

Sending it to the ordinary 1120 address is a real failure mode. The filing does not bounce back with a helpful note.

The extension is automatic and Form 7004 is what requests it:

"Use Form 7004 to request an automatic 6-month extension of time to file certain business income tax, information, and other returns."

IRS, About Form 7004. Page last reviewed or updated March 30, 2026. The IRS page does not enumerate which returns; the October 15 date is six months from April 15.

Nobody told the owner it existed. The most common and the most expensive. A formation service filed the LLC, mentioned nothing about annual federal information reporting, and the first notice arrives from the IRS.

"I had no transactions." Capital contributions and owner-paid expenses are reportable. Almost every first-year LLC has some.

Sent to the wrong address. The ordinary Form 1120 addresses are wrong for this filing and the instructions say so directly.

Filed electronically, or attempted. There is no e-file path. Software that appears to accept it is usually filing something else.

The 1120 was completed properly. Only name, address, and items B and E are required. A fully populated 1120 is not a safer version of a pro forma one.

If your LLC has more than one member it is a partnership by default, not a disregarded entity, and you file Form 1065 with K-1s instead. Different form, different rules, and withholding obligations on foreign partners enter the picture.

If your LLC elected to be taxed as a corporation, you file a real 1120 and Form 5472 attaches to that rather than to a pro forma shell.

If the LLC is owned by a US person, this page is not about you.

What if I had genuinely no transactions at all? Check what counts before concluding that. Money you put in to open the bank account is a capital contribution and is reportable. So is a domain renewal you paid on your own card. The threshold for "reportable transaction" is lower than most founders assume.

Can I file this myself? Mechanically, yes. It is a short form and a nearly blank 1120, sent by fax or mail. Whether you should depends on whether you can identify your reportable transactions correctly, which is the part that carries the risk rather than the paperwork.

What happens if I just don't file? The base to start. If the failure continues past the cure window after the IRS notifies you, a further base amount per related party for each 30-day period or part of one. The continuation penalty has no natural ceiling in the way the base penalty does.

I missed last year. What now? File. The continuation penalty is triggered by continued failure after IRS notification, so the position before any notice is materially better than after one. Reasonable-cause relief exists and is its own subject.

Does an extension on Form 7004 extend the payment too? There is generally no tax to pay on a pro forma 1120 for a disregarded entity, because it is an information filing rather than a return reporting the entity's own income tax. Your personal position is separate and is not covered here.