Annualized income installment method or adjusted seasonal installment method (attach schedule) 2026

1. Click ‘Get Form’ to open it in the editor.
2. Begin by entering your EIN and the name shown on your return at the top of the form.
3. In Part I, compute your underpayment by filling in line 1 with your net income tax. Refer to the instructions for accurate calculations.
4. Complete lines 2a and 2b by including any personal holding company tax and look-back interest, respectively.
5. Subtract line 2d from line 1 on line 3. If this amount is less than $500, you do not need to complete the rest of the form.
6. On lines 4a, 4b, and 4c, enter the required amounts as instructed to determine your installment due dates.
7. Finally, fill in columns A through D with the installment due dates corresponding to each quarter of your tax year.

Start using our platform today for free to streamline your document editing and form completion!