Item C. — Instruction 1120-S — Instructions for Form

For 2025, a corporation that (a) is required to file Schedule M-3 (Form 1120-S), Net Income (Loss) Reconciliation for S

Instructions for Form 1120-S (2025) 13

Corporations With Total Assets of $10 Million or More, and has less than $50 million total assets at the end of the tax year or (b) isn’t required to file Schedule M-3 (Form 1120-S) and voluntarily files Schedule M-3 (Form 1120-S) must either complete Schedule M-3 (Form 1120-S) entirely or complete Schedule M-3 (Form 1120-S) through Part I and complete Schedule M-1 (Form 1120-S), instead of completing Schedule M-3 (Form 1120-S), Parts II and III. If a corporation chooses to complete Schedule M-1 (Form 1120-S), instead of completing Schedule M-3 (Form 1120-S), Parts II and III, Schedule M-1 (Form 1120-S), line 1, must equal Schedule M-3 (Form 1120-S), Part I, line 11.

Any corporation that completes Parts II and III of Schedule M-3 (Form 1120-S) must complete all columns, without exception.

If the corporation has changed its address since it last filed a return (including a change to an “in care of” address), check the “Address change” box.
If this amends a previously filed return, check the “Amended return” box. If Schedules K-1 are also being amended, check the “Amended K-1” box on each Schedule K-1.
If the corporation has terminated its S election, check the “S election termination” box. See Termination of Election , earlier.

If you are filing Schedule M-3, check the “Check if Sch. M-3 attached” box. See the Instructions for Schedule M-3 for more details.