When you are a non-resident founder with a U.S. company, one of the first challenges you face is figuring out compliance. Incorporating in Delaware or Wyoming may have been easy, but filing correctly with the IRS is another story. The U.S. tax system is strict, and missing a deadline can trigger fines of thousands of dollars.
The most confusing part for many global founders is understanding whether their company falls under the March 15 or April 15 deadline. These two dates are the backbone of the IRS calendar for non-resident founders, and they apply differently depending on your entity type.
At Bookmate, we work with hundreds of international founders each year who are surprised when they learn that their filing date is not what they assumed. The IRS does not send reminders and does not care if you live in another time zone. If you are late, you are penalized.
This article will give you a clear map of which entities file in March, which ones file in April, and how to make sure you never miss your deadline.
Why Deadlines Matter
Missing a filing deadline is not a small mistake. For non-resident founders, the penalty for missing required IRS forms is $25,000 per entity, per year. That penalty applies even if your company has no revenue.
In addition to penalties, missing a filing can damage your ability to raise capital or maintain a U.S. bank account. Investors often request proof of compliance during due diligence, and banks may flag your account if your company is not in good standing. In other words, deadlines are not just about avoiding fines. They are about keeping your company alive and trusted.
March 15: Multi-Member LLCs
If your U.S. company is a Multi-Member LLC (MMLLC), your deadline is March 15.
By default, the IRS classifies an MMLLC as a partnership. That means your company must file Form 1065 (U.S. Return of Partnership Income).
Form 1065 reports the LLC’s total income, deductions, and distributions to its members. Each member then receives a Schedule K-1 to report their share of income on their own tax return. Even if the company has no revenue, the form must be filed to show the IRS that the business is compliant.
Because this involves multiple members, the IRS sets the deadline one month earlier than corporations or single-member LLCs. The reason is that the members often need their K-1 documents in time to prepare their own filings.
If you have a multi-member LLC, circle March 15 on your calendar. Filing after that date means immediate penalties.
April 15: Single-Member LLCs and C-Corporations
For most non-resident founders, the critical date is April 15. This deadline applies to both foreign-owned Single-Member LLCs and C-Corporations.
1. Single-Member LLCs (SMLLCs)
If you own a U.S. LLC by yourself, the IRS classifies it as a disregarded entity. That means the LLC does not pay federal income tax itself, but it must still report its existence.
Your filing includes:
- Form 5472 – An informational return that reports transactions between your U.S. LLC and you as the foreign owner. Transactions include transfers of money, loans, or payments for services. Even if you did not move funds, the form must be filed.
- Pro Forma Form 1120 – A cover page for Form 5472.
This package is due on April 15 each year. Missing it results in the $25,000 penalty.
2. C-Corporations
If you incorporated your business as a C-Corp, you also file on April 15. Unlike LLCs, corporations are separate taxable entities. They file Form 1120 (U.S. Corporation Income Tax Return), which reports all income, deductions, and taxes owed.
Even if your C-Corp made no money, the form is mandatory. If you had revenue, you may also owe corporate taxes. Extensions are available, but only if filed before April 15.
Why Two Different Deadlines Exist
At first glance, it seems strange that some companies file in March and others in April. The difference comes down to how the IRS classifies entities:
- Multi-Member LLCs are partnerships. Partnerships file earlier so that members have their K-1 forms in time for their own taxes.
- Single-Member LLCs are disregarded entities. The IRS sets their deadline in line with corporations on April 15.
- C-Corporations are taxed directly and also follow the April 15 schedule.
For global founders, this creates confusion because two people may both say “I have a U.S. LLC,” yet one faces a March deadline and the other an April deadline.
The Global Founder’s Trap
For non-resident founders, the challenge is not just knowing which deadline applies. It is also the lack of reminders. The IRS does not send notifications. They expect you to know.
At Bookmate, we often hear the same story: a founder forms a U.S. company, assumes they do not need to file because there was no revenue, and months later receives a penalty notice for $25,000. The fine is real, the deadline was missed, and the IRS is not flexible.
This silent trap catches thousands of founders every year. The only way to avoid it is to know your deadline in advance and prepare.
How Bookmate Helps Founders Stay Compliant
Bookmate was built to solve this problem for non-resident founders. Our process ensures that no matter where you live, you never miss your filing.
Here is how we do it:
- Entity classification at onboarding – We identify whether you have a single-member LLC, a multi-member LLC, or a C-Corp, so your deadline is clear from the start.
- Year-round reminders – We do not wait until tax season. You receive reminders months ahead, adjusted to your time zone.
- CPA-led filings – Our licensed professionals prepare and submit your forms directly, removing the guesswork.
- Penalty prevention – Because we stay ahead of deadlines, our clients avoid the $25,000 fines that surprise so many founders.
With Bookmate, compliance is no longer a stressful guessing game. It becomes a simple, reliable system.
The IRS Deadline Map at a Glance
To make this simple, here is the breakdown:
- March 15 – Multi-Member LLCs (Form 1065)
- April 15 – Foreign-owned Single-Member LLCs (Form 5472 with Pro Forma 1120)
- April 15 – C-Corporations (Form 1120)
That is the entire IRS deadline map for non-resident founders. Once you know where your company fits, you know your filing date.
Conclusion
Forming a U.S. entity is easy. Staying compliant is the real challenge. The IRS won’t send reminders—and missing a deadline can cost you $25,000 or more.
The key is knowing which deadline applies to your situation: March 15 for multi-member LLCs, and April 15 for single-member LLCs or C-Corporations. Once you understand the map, it’s much easier to stay compliant and protect your business.
That’s where Bookmate comes in. We track your deadlines, prepare your forms, and file everything on time—so you can focus on growing your business, not worrying about IRS penalties.
Book your free consultation with Bookmate today and let’s make U.S. compliance stress-free.
