FileTax

This catches people every year, so it's worth saying plainly.

If you own a US single-member LLC and you're not a US person, you almost certainly have to file IRS Form 5472 with a pro forma Form 1120. Every year. This is true even if the LLC made no money, has no employees, has never had a customer, and exists only to hold a Stripe account.

Most people assume "no income, no filing." That's correct for some things. It is not correct for this one.

What makes it worth knowing about:

The penalty for not filing is $25,000 per form, per year, under IRC section 6038A. There's no small-business exception and no de minimis threshold. A dormant LLC owes the same filing as an active one, and the penalty is identical.

The form is also mostly zeros. That's the part people find hardest to believe. It's largely identifying information about the LLC and its related parties, plus reportable transactions between them. If you formed the LLC yourself and funded it from your own account, those transactions are usually your own contributions, which still have to be reported.

A few things that trip people up:

- The deadline is the 1120 deadline, April 15, not any state filing date you may already be tracking.

- It's filed by mail or fax, not through the usual e-file paths, which is why consumer tax software doesn't handle it.

- Missed years don't go away. You can file them late, and there's a reasonable cause process, but the exposure compounds per year, per form.

- Having a US LLC with zero activity is the single most common case here, not an edge case.

If you're reading this and realising it applies to you, the useful next step is working out which years you actually owe, before worrying about the filing itself. That answer is usually shorter than people expect.

Happy to answer questions in the comments.

(Disclosure: I build FileTax, which does this filing. Not linking it here, this post isn't about that.)