2026 Tax Year Filing Deadlines for Foreign-Owned LLCs (Form 5472 & 1120)

The Key Date: April 15, 2027

For a calendar-year foreign-owned single-member LLC (the default for almost every LLC formed through Stripe Atlas, Firstbase, doola, or a state directly), the tax year 2026 return is due April 15, 2027.

That return is the same package you file every year: Form 5472 attached to a pro forma Form 1120, covering transactions between you and the LLC during the 2026 calendar year. The $25,000 penalty under IRC §6038A for late or incomplete filing applies to tax year 2026 exactly as it does to prior years — it is a statutory amount set by Congress and does not change year to year.

Extension Deadline: October 15, 2027

If you cannot file by April 15, 2027, request an automatic 6-month extension with Form 7004 before that date. That pushes your filing deadline to October 15, 2027. Form 7004 is free and automatic — there is no reason not to file one if you need more time.

Mail or fax Form 7004 to the same Ogden, UT address or fax number used for Form 5472 itself, and write "Foreign-owned U.S. DE" across the top. The extension covers filing only — if your LLC somehow owes tax (rare for a disregarded entity with no U.S. trade or business), that amount is still due April 15, 2027.

First-Year LLCs Formed in 2026

If you form your LLC any time during 2026, your first tax year begins on the date of formation and ends December 31, 2026. Even if the LLC is only a few weeks old and has had only one transaction (your initial capital contribution), you still owe a 2026 Form 5472 by April 15, 2027.

The IRS does not waive the filing requirement for newly formed LLCs. The penalty for missing a first-year filing is the same $25,000 as any other year. Plan to file your first return the spring after formation, not a year later.

Important: 2026 Forms Are Not Yet Final

As of April 2026, the IRS has not yet released the final tax year 2026 versions of Form 5472 or Form 1120. The current posted revision of Form 5472 is December 2023 (with instructions updated December 2024), and the most recent Form 1120 is the 2025 tax year version.

Draft TY2026 forms typically appear on irs.gov/draft-tax-forms in mid-to-late summer (July through September), near-final versions in October or November, and final versions in December 2026 or early January 2027. You cannot submit a TY2026 return against a draft form — always wait for the final version before filing, or file before the tax year ends using the prior year's form for catch-up purposes only.

Dates to Put on Your Calendar Now

For tax year 2026 as a foreign-owned single-member LLC:

• July–September 2026 — watch for TY2026 draft forms on irs.gov/draft-tax-forms • October–November 2026 — Revenue Procedure 2026-XX publishes inflation-adjusted amounts (standard deduction, brackets, mileage rate — not the $25,000 penalty, which is statutory) • December 2026 / January 2027 — final TY2026 Form 5472 and Form 1120 expected on irs.gov • April 15, 2027 — TY2026 filing deadline • October 15, 2027 — extended deadline if you file Form 7004 before April 15, 2027

ForeignLLCTax.com subscribes reminder emails 30 days, 2 weeks, and 5 days before the April 15 deadline — see our /tools page.