Form 1120 Tax Year Demo: Beginning, Ending & Short-Year Filings

Where the Tax Year Fields Live on Form 1120

At the very top of Form 1120, page 1, you'll find a header line that reads: "For calendar year [YEAR], or tax year beginning [MONTH] [DAY], [YEAR], and ending [MONTH] [DAY], [YEAR]."

This line is the IRS's way of capturing your tax year regardless of whether you're a calendar-year, fiscal-year, or short-year filer. Below it are checkboxes for various filing statuses (Initial return, Final return, Name change, Address change) — but the tax year line itself is the substantive part.

The tax year on Form 1120 must match the tax year on Form 5472 exactly. Any mismatch is a processing red flag.

How to Enter Calendar-Year Dates

If you're a standard calendar-year filer (most foreign-owned LLCs are), filling the tax year line is straightforward:

- Write or print "2025" (or the relevant year) in the calendar year field. - Leave the "tax year beginning" and "tax year ending" fields blank — OR — fill them with 01-01-2025 and 12-31-2025 explicitly.

The IRS treats both approaches as equivalent. Filling the explicit dates is the safer practice because it removes any ambiguity. Software-prepared returns typically fill the explicit dates by default.

How to Enter Short-Year Dates

For a short tax year, leave the "calendar year" field blank and fill the "tax year beginning" and "tax year ending" fields with the explicit short period.

First-year example: LLC formed October 15, 2025. Calendar year field: blank. Tax year beginning: 10-15-2025. Tax year ending: 12-31-2025.

Final-year example: LLC dissolved June 30, 2026. Calendar year: blank. Tax year beginning: 01-01-2026. Tax year ending: 06-30-2026.

Accounting period change example: LLC transitions from calendar year 2024 to fiscal year ending September 30, 2025. Calendar year: blank. Tax year beginning: 01-01-2025. Tax year ending: 09-30-2025.

Format Conventions

Two format conventions to follow:

1. Date format: MM-DD-YYYY (the U.S. convention). Don't use DD/MM/YYYY (European format) — it'll be misread. Don't use YYYY-MM-DD (ISO format) — also misread by IRS optical character recognition.

2. Year-only field: Use the four-digit year (2025, not 25). The IRS form has space for four digits.

If typing into the PDF, the IRS fillable form usually has the date format pre-set. If hand-writing, use clear ASCII numerals and dashes/slashes.

What Happens if You Get the Tax Year Wrong

Common tax-year mistakes and their consequences:

Leaving both fields blank (no calendar year, no explicit dates): the IRS treats this as a substantially incomplete filing. CP-notice asks you to complete the field.

Mismatched dates between Form 1120 and Form 5472: the IRS may treat the filing as deficient under §6038A. CP-notice asks you to clarify — usually with a corrected pair of forms.

Wrong year (e.g., reporting 2024 transactions on a 2025-marked form): the IRS doesn't always catch this on initial filing, but it surfaces on examination. The wrong year is treated as the year you filed for — meaning your prior year's filing is now missing, which can trigger the §6038A penalty for the missing year.

Short year disguised as calendar year (checking calendar year when you formed mid-year): looks complete to the IRS but creates audit risk later. If they pull formation documents and see a mid-year formation, the "calendar year" claim becomes evidence of substantially incomplete or false filing.

Get the tax year right. It's the single most-checked field in the IRS examination process.