Form 1120

What is a pro forma Form 1120?

Form 1120 is the US corporate tax return. Your LLC does not really file one, but Form 5472 has to be attached to something — so a nearly empty (“pro forma”) 1120 is used as its cover page.

Form 5472 is an attachment, not a return: it cannot be sent to the IRS on its own. A foreign-owned single-member LLC therefore files a Form 1120 with only the required identifying details filled in — name, address, EIN and item E — and Form 5472 attached behind it.

“Pro forma” is the IRS's own word for this. It means the form is there to carry the attachment, not to report income. Filing it does not make your company liable for corporate tax, and the income lines stay empty.

Neither form can be filed electronically for a foreign-owned disregarded entity. The package goes to a dedicated IRS address, by fax or by post.