Form 5472 Tax Year and Due Dates: Calendar Year, Fiscal Year, and Your First Filing

One of the most common questions we receive from international founders is not whether to file Form 5472, but which dates to use. Should the return cover January to December? What if your company was formed in August? Does your home country's tax year matter? Getting these dates right affects both the information you report and the deadline you must meet. This guide sets out the rules that apply to foreign-owned U.S. single-member LLCs and shows how to apply them.

What "tax year" means on Form 5472

A tax year is the 12-month accounting period a business uses to report to the IRS. There are two kinds:

• Calendar year: January 1 to December 31.
• Fiscal year: any other 12-month period, for example April 1 to March 31.

Both Form 5472 and the pro forma Form 1120 ask you to state the tax year the return covers. Every transaction you report, such as capital you put into the company or money you take out, must fall inside that period.

How a foreign-owned LLC's tax year is set

A foreign-owned U.S. single-member LLC is a "disregarded entity" for income tax purposes but is treated as a corporation for Form 5472 reporting. The IRS instructions for Form 5472 state that such an entity has the same tax year used by its owner for U.S. tax filing requirements or, if none, the calendar year.

In practice, this means:

• If you, the owner, do not file any U.S. tax return, which is the position of most foreign owners, your LLC uses the calendar year.
• If you do file a U.S. return (for example, a foreign company that files Form 1120-F on a fiscal year), the LLC follows that same U.S. tax year.

How to work out your due date

The pro forma Form 1120, with Form 5472 attached, is due by the due date of Form 1120: the 15th day of the fourth month after the end of the tax year. If that day falls on a weekend or a federal holiday, the deadline moves to the next business day.

Your first tax year

Your LLC's first tax year begins on the date the company was formed, as shown on your Articles of Organization, and ends on the last day of its tax year. For a calendar-year LLC, that is December 31 of the same year. This shorter period is known as a short tax year, and it still requires a full Form 5472 filing.

For example, an LLC formed on August 20, 2026 has a first tax year of August 20 to December 31, 2026. Its first Form 5472 and pro forma Form 1120 are due on April 15, 2027.

Entering the dates on the forms

• Pro forma Form 1120: for a full calendar year, enter the year at the top of the form. For a short first year or a fiscal year, enter the exact beginning and ending dates. Write "Foreign-owned U.S. DE" across the top, as the IRS instructions require.
• Form 5472: enter the same beginning and ending dates as the Form 1120. In your first filing year, check the box on line 1j to show that this is the first year the company has filed Form 5472.
• Supporting records: make sure the bank statements and expense records you rely on cover exactly the same period.

Extending the deadline with Form 7004

If you need more time, file Form 7004 by the original due date. For a calendar-year LLC, that is April 15. A valid extension moves the filing deadline back six months, to October 15. Keep in mind:

• The extension must be filed on or before the original due date. It cannot be requested after the deadline has passed.
• A foreign-owned LLC sends Form 7004 to the same fax number or mailing address used for the return itself, not the addresses in the general Form 7004 instructions.
• The extension gives you more time to file. It does not reduce the information you must report.

Where the return is sent

A foreign-owned U.S. single-member LLC cannot file Form 5472 electronically. According to the current IRS instructions, the pro forma Form 1120 with Form 5472 attached is either:

• faxed to the IRS at 855-887-7737, or
• mailed to: Internal Revenue Service, 1973 Rulon White Blvd., M/S 6112, Attn: PIN Unit, Ogden, UT 84201.

Keep proof of the date you sent it, such as the fax confirmation or the postal receipt.

Closing the company

If you dissolve your LLC, a final return is generally still required. It covers the period from the start of that tax year to the date the company closes, and any transactions with you during that period must be reported. Confirm the final-year rules for your situation before you close the company.

Common date mistakes to avoid

• Using your home country's tax year instead of the U.S. calendar year.
• Starting the first tax year on the date the EIN was issued or the bank account was opened, rather than the formation date.
• Skipping the first year because it was short or the LLC had no income.
• Filing Form 7004 after April 15. A late extension request is not valid.
• Reporting transactions that fall outside the tax year shown at the top of the form.

Why the dates matter

The penalty for failing to file Form 5472 when due, or filing it substantially incomplete, is $25,000 per form, per tax year, with further penalties if the failure continues after an IRS notice. Correct dates and an on-time filing are the simplest protection against this risk.

How Meritline Tax helps

We confirm your LLC's tax year and filing dates, prepare Form 5472 with the pro forma Form 1120, file Form 7004 extensions when needed, and send your return to the IRS. If you have missed one or more years, we prepare catch-up filings with a reasonable cause statement. Filings start at $200, confirmed in a written quote before any work begins.

This article is general information based on the IRS Instructions for Form 5472 (Rev. December 2024) and federal rules as of October 15, 2026. It is not tax or legal advice for your specific situation. Rules, addresses, and due dates can change, so confirm your requirements before you file.