If you’re reading this after the March or April deadline passed without a filing, take a breath. You’re not the first founder this has happened to, and the situation is usually fixable. But the steps you take in the next few weeks matter, and some of the advice circulating online about your options is just wrong. Filing late but with the right approach is typically an effective way to mitigate risk.

This post covers what the penalties actually are for each entity type, what you should do right now, and how to approach penalty relief. The rules are different depending on whether you own a single-member LLC, a multi-member LLC, or a C Corp, so the starting point is knowing which deadline applied to you.

Key takeaways

  • Filing late is better than not filing at all. Every month of delay increases penalty exposure for LLCs and C Corps.
  • First-time abatement does not apply to Form 5472 penalties. If you own a foreign-owned single-member LLC or C Corp and didn’t file the required Form 5472 on time, then FTA is not your path.
  • “I had no income” does not mean you had no filing obligation. For businesses that must file Form 5472, the trigger is reportable transactions, not income. A capital contribution counts. (Note: multi-member LLCs = partnerships are different.)
  • You cannot request an extension with Form 7004 retroactively. If the deadline passed with no extension request, you are simply late. The only move now is to file as quickly as possible.
  • Penalty assessment for foreign-owned SMLLCs is not automatic. The $25,000 penalty for a late Form 5472 is typically assessed with an IRS notice, not immediately on day one. That said, waiting for a notice is not a strategy.

Not sure where your situation falls? Reach out to the Entity Inc. team and we’ll help you figure out the right next step.

Which US tax deadline applied to your LLC or C Corp?

The US tax deadline depends on your entity type.

March 15 was the deadline for multi-member LLCs treated as partnerships. These entities file Form 1065. In addition, each member should have received a Schedule K-1, which reports each partner’s share of the partnership’s taxable income, losses and other tax attributes. 

If you didn’t file an extension (Form 7004) by March 15, the partnership return is now late.

April 15 was the deadline for two groups: 

  • foreign-owned single-member LLCs, which file Form 5472 attached to a pro forma Form 1120; and 
  • Foreign-owned C Corporations, which file Forms 1120 and 5472. 

One point that catches founders off guard: the extension deadline is the same as the filing deadline. Form 7004 had to be submitted by March 15 for partnerships and April 15 for SMLLCs and C Corps. If that window closed without an extension request, there is no retroactive fix. You are filing late, and the goal now is to do it as quickly and cleanly as possible.

What are the penalties for filing a US business tax return late?

The penalties differ significantly by entity type, and some are more severe than most foreign founders expect. Here is what each structure faces.

Late Form 5472 penalty: how much, and when is it assessed?

Foreign-owned single-member LLCs must file Form 5472 attached to a pro forma Form 1120, to disclose reportable transactions, even if the LLC had no income. The statutory penalty for failing to file, or filing late, starts at $25,000 per form, per tax year.

In practice, this penalty is typically assessed after the IRS sends a notice, not automatically on the filing deadline. That distinction matters: voluntary, proactive filing before a notice is issued puts you in a materially better position than waiting. If the IRS does send a notice and 90 days pass without a response, an additional $25,000 can apply for each subsequent 30-day period, with no cap.

There is also a less-discussed consequence worth knowing: when you don’t file Form 5472, the IRS’s statute of limitations on assessment remains open indefinitely. The clock only starts once the form is filed.

Reportable transaction:

Any monetary and non-monetary exchange between a foreign-owned LLC and a related party, including the foreign owner. This covers capital contributions, owner reimbursements, and expenses the owner paid on the LLC’s behalf. A reportable transaction does not require income.

Late-filing penalty for a multi-member LLC (Form 1065)

A multi-member LLC is taxed as a partnership by default. The late-filing penalty for a partnership is $220 per partner, per month, up to 12 months. 

To illustrate: a three-partner LLC filing four months late faces a $2,640 penalty before any other consideration.

The good news for partnerships: first-time abatement is available, unlike for Form 5472 (more on that below). Other penalty relief options may also apply to partnerships. Discuss with an experienced tax professional.

What happens if a C Corp misses the filing deadline?

The failure-to-file penalty for a C Corp is 5% of unpaid tax per month, up to a maximum of 25%. If the corporation owes no US tax, common for early-stage or foreign-owned C Corps without US-source income, this specific penalty is effectively zero.

However, if the C Corp had reportable transactions with a foreign shareholder and Form 5472 was required, the $25,000 penalty framework applies independently. The absence of a tax liability does not eliminate the Form 5472 obligation.

I missed the LLC tax deadline. What should I do now?

File as soon as possible, even if you cannot pay anything owed. This applies regardless of entity type.

For partnerships and C Corps, every additional month of delay adds to the penalty. For foreign-owned SMLLCs, filing before the IRS issues a notice demonstrates good faith and puts you in a better position for a relief request, in case a penalty comes later.

A few practical points:

  • Gather what you need first. You will need the entity’s EIN, records of any reportable transactions (including capital contributions and owner-paid expenses), and prior year returns if applicable. Make sure you have good records. The IRS can also assess the $25,000 penalties for missing records or incorrect filing.
  • Single-member LLCs cannot file Form 5472 electronically. For foreign-owned single-member LLCs, this form must be mailed or faxed to the IRS’s Ogden, Utah address. Filing to the wrong address can result in rejection and renewed penalty exposure. The correct mailing address is: Internal Revenue Service, 1973 Rulon White Blvd, M/S 6112, Attn: PIN Unit, Ogden, UT 84201. 
  • You cannot file Form 7004 retroactively. If the deadline passed without an extension request, that window is closed. The only path now is to file the return itself as quickly as possible. 
  • Do not wait for a notice to act. Especially for Form 5472, where a notice starts a 90-day clock that, if missed, can double the exposure. Filing voluntarily shows good faith and puts you in a better position to request penalty relief.

Can I get the IRS penalty reduced or removed?

Yes, in many cases you can reduce or eliminate the IRS penalty, but the path depends on your entity type and which form was late. There are two main options:

  • First-time abatement – available to multi-member LLCs (partnerships) but not to businesses that must file Form 5472: foreign-owned single-member LLCs and C Corps
  • Reasonable cause relief – available to all entities, including foreign-owned single-member LLCs and C Corps 

We explain both in detail below. 

(There is a third option for certain partnerships, Revenue Procedure 84-35, with a more limited scope.)

While these paths can reduce or remove penalties, they will not reduce interest that accrues on any unpaid tax from the original due date until paid in full. For most foreign-owned entities with no US-source income and no tax liability, interest is a non-issue. But it is worth confirming before assuming this applies to you.

Does first-time abatement apply to Form 5472 penalties?

No, and this is one of the most widely misunderstood points in this space.

First-time abatement (FTA):

An IRS administrative waiver that removes a single failure-to-file or failure-to-pay penalty for taxpayers that have a clean compliance history, meaning no penalties of the same type in the three prior tax years, all required returns filed, and any tax owed paid or in an arrangement with the IRS.

FTA is available for the failure-to-file penalty on Form 1065 (partnership) and Form 1120 (C Corp), provided you have a clean compliance record for the prior three tax years. To request it, call the number on your IRS notice or submit Form 843. Or contact us – our team has experience with first-time abatements.

FTA simply does not apply to Form 5472 penalties. I see this stated incorrectly on Reddit, in online forums, and in AI-generated answers regularly. If you own a foreign-owned single-member LLC and filed Form 5472 late, FTA is not available to you. 

— Vincenzo Villamena, CPA — CEO at Entity Inc.

Instead of FTA, the IRS recommends a reasonable cause statement, and those are two different things with different standards and different outcomes.

What is reasonable cause relief, and does it apply to my situation?

Reasonable cause is the relevant relief path for most foreign entrepreneurs. And it is the only abatement option available for Form 5472 penalties. The standard is whether you exercised ordinary business care and prudence but still could not comply on time.

Foreign founders often have genuine reasonable cause but simply saying “I didn’t know” is not enough. The statement wording is important.

Reasonable cause relief requires a written explanation submitted to the IRS, either attached to the late-filed return or via Form 843 if a penalty has already been assessed.

If you need help, reach out to our team directly.

Does a zero-income LLC still owe a penalty for not filing?

Potentially yes, and this is the misconception that costs foreign founders the most.

The filing obligation for a foreign-owned LLC is not based on income; it is based on reportable transactions. The moment you contributed capital to your LLC, or your LLC paid a registration fee, or reimbursed you for a business expense, you had a reportable transaction, and that requires. Form 5472. An LLC with genuinely zero activity and zero transactions may have a defensible position, but that bar is much higher than most people assume.

— Vincenzo Villamena, CPA — CEO at Entity Inc.

When should I get a tax professional involved in a late filing situation?

If you have already received an IRS notice, get a US tax professional involved immediately before filing or responding to any IRS notice. The 90-day response window is not generous, and missing it doubles the exposure.

If you missed the deadline and are filing late now, but haven’t received an IRS notice, a tax specialist can help you file properly. A poorly worded submission or filing mistakes can weaken a case that would otherwise succeed.

Clean books also matter here. A reasonable cause argument is stronger when you can clearly show what transactions occurred, when they occurred, and what amounts were involved. If your records are incomplete, that is worth addressing now, not only for the relief or abatement letter, but for ongoing compliance.

Reach out to the Entity Inc. team. We work with foreign founders in exactly this situation and can help you assess your exposure, file what needs to be filed, and put together the strongest case for relief available to you.

FAQ

What happens if I missed the April 15 deadline for my foreign-owned LLC?

You are now late on Form 5472 and the pro forma Form 1120. The statutory penalty is $25,000, though it is typically assessed after an IRS notice rather than automatically. File as soon as possible — proactive filing before a notice is your best position.

Can I still file Form 5472 after the deadline?

 Yes. There is no cutoff after which you simply cannot file. Submit the form as soon as it is ready, include a cover letter or reasonable cause statement explaining the circumstances, and mail it to the correct IRS address in Ogden, Utah or fax it. Foreign-owned SMLLCs cannot use electronic filing.

Is first-time abatement available for Form 5472 penalties?

No. FTA applies to failure-to-file and failure-to-pay penalties on income tax returns — not to Form 5472 information return penalties. The correct relief path is reasonable cause, which requires a written explanation demonstrating that you exercised ordinary care but still could not comply on time.

What is a reasonable cause letter, and does it work?

A reasonable cause letter is a written statement submitted to the IRS explaining why you could not file on time despite exercising ordinary business care. You can submit it together with the late return or in response to a penalty assessment. Our team can help you determine the best approach.

My LLC had no income. Do I still owe a penalty for filing late?

Potentially yes. For a foreign-owned single-member LLC, the filing obligation is based on reportable transactions, not income. If there were any financial flows between you and the LLC, e.g., a capital contribution, a formation fee, a business expense you paid, Form 5472 was required regardless of whether the LLC earned anything. (The same applies to foreign-owned C Corps.)

How do partnership late-filing penalties work?

The penalty is $220 per partner per month, up to 12 months. A two-partner LLC filing three months late owes $1,320. The penalty accrues even if the partnership owes no tax. First-time abatement is available if the partnership has a clean three-year compliance history.