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 in Draft, Not Final

Status checked September 1, 2026. Sort the forms into three buckets rather than one list.

Final, and safe to build on: the 1099-NEC, 1099-MISC and 1099-K at Revision December 2026 with instructions dated 12/2026, the 2026 Form 1099-DA, and the 2026 Form 1042-S.

Draft only: Form 5472 (Rev. December 2026, posted June 2), Form 1120 (2026, June 1), Form 1065 (2026, July 17, with Schedule K-1 May 21 and Schedules K-2 and K-3 June 17), Form 8804 (Rev. December 2026, June 9), Form 8832 (December 2026, May 20), Form SS-4 (December 2026, July 27) and Form 1042 (2026, April 30).

The currently published Form 7004 is Revision December 2025 and Form W-7 is Revision December 2024. Recheck the IRS form pages before filing; absence of a newly posted draft does not guarantee that no revision will follow. Form 8832 is the one to watch — it has carried a December 2013 revision for thirteen years.

Drafts are planning documents marked DRAFT — DO NOT FILE. Do not submit them, and do not use a TY2025 form for a TY2026 return. Wait until the IRS publishes the final TY2026 form and instructions at irs.gov/latest-forms before generating or filing the actual package. Prior-year forms remain relevant only to a return for that prior tax year, including a late or amended filing.

Dates to Put on Your Calendar Now

For a calendar-year foreign-owned single-member disregarded LLC:

• August–December 2026 — monitor draft revisions and wait for final forms and instructions • December 2026 / January 2027 — final TY2026 Form 5472 and Form 1120 are expected on irs.gov/latest-forms • April 15, 2027 — TY2026 Form 5472 plus pro forma Form 1120 deadline • October 15, 2027 — extended filing deadline if a valid Form 7004 is filed by April 15

A multi-member LLC taxed as a partnership follows a different calendar: its calendar-year Form 1065 and partner schedules are generally due March 15, 2027. Owner-level Form 1040-NR deadlines also depend on whether the nonresident received wages subject to U.S. withholding. Do not reuse the single-member LLC deadline for every foreign-owned LLC scenario.