H. Accounting Period

Calendar or fiscal year. File the 2025 return for the calendar year 2025 or fiscal year beginning in 2025. If the return is for a fiscal year, fill in the beginning and ending dates of the tax year in the spaces at the top of the return.

The return must be filed on the basis of the established annual accounting period of the organization. If the organization has no established accounting period, the return should be on the calendar-year basis.

Short period. For an initial or final return or for a short tax year resulting from a change in accounting period, the 2025 form may also be used as the return for a short period (less than 12 months) ending November 30, 2025, or earlier. The 2025 form may also be used for a short period beginning after November 30, 2025, and ending before December 31, 2026 (not on or after December 31, 2026). Note on the short period return the change of accounting period.

Accounting period change. If the organization changes its accounting period, it must file a Form 990 for the short period resulting from the change. If you are filing a short period return because you changed your accounting period, use the change of accounting period field provided by the software provider to file. Also, include the reason for the change, either “Form 1128 was approved” or “Revenue Procedure 85-58 rules apply.”

If the organization has previously changed its annual accounting period at any time within the 10-calendar-year period that includes the beginning of the short period resulting from the current change in account period, and it had Form 990 series or income tax return filing requirement at any time during the 10-year period, it must also file Form 1128, Application To Adopt, Change, or Retain a Tax Year, with the short-period return. See Rev. Proc. 85-58, 1985-2 C.B. 740. See also IRS.gov for further instructions.