How to Fill Form SS-4 Line 12: Accounting Year Closing Month

November 13, 2026 · 2 min read

Form SS-4 line 12 asks for the final month of your accounting or tax year. Enter December for a calendar-year filer. For a fiscal year, identify the closing month from the applicable tax year before completing the form.

What to check

The month the company started or was acquired belongs to a separate question on line 11. A new business can start in July and still use December for line 12. Tax-year rules depend on how the entity is treated for U.S. tax purposes. The IRS gives separate rules for individuals, partnerships, and certain corporations or trusts. For the Form 5472 filing of a foreign-owned U.S. disregarded entity, the instructions specify the owner’s tax year used for U.S. tax filing or the calendar year if the owner has no such tax year.

Example

A foreign individual forms a U.S. single-member LLC in August. The LLC is a disregarded entity and the owner has no tax year used for U.S. tax filing. In this fact pattern, the Form 5472 instructions use the calendar year. The founder documents that reason and records December as the closing month without treating August as the year end.

Before you proceed

Separate the starting or acquisition date on line 11 from the closing month on line 12.
Check the entity’s U.S. tax classification and the rule that applies to its reporting year.
If the records show inconsistent closing months, verify the tax year before submitting.

Does a July formation date mean I should enter July on line 12?

No. A July formation date by itself does not establish the accounting year. Enter the month the applicable accounting or tax year closes.