OW-8-P-SUP-I: 2025 Form OW-8-P-SUP-I Annualized Income Installment Method for Individuals (2025)
Oklahoma · Oklahoma Tax Commission · Used for tax years 2025
Oklahoma Form OW-8-P-SUP-I is a schedule for individuals using the annualized income installment method to calculate required estimated tax installments. It uses income, deductions, adjustments and credits for four periods of the year to determine installment amounts to enter on
Who files this form
Form OW-8-P-SUP-I is for individuals using the annualized income installment method to figure their required Oklahoma estimated tax installments for 2025.
If you use this form for any payment due date, you must use it for all payment due dates. Part-year residents and nonresidents filing Form 511-NR must follow the special instructions on page 2.
What you'll need
Have these forms and information ready:
- Form OW-8-P, with Section Two, Part 1 completed.
- Your Oklahoma income tax return, Form 511 or Form 511-NR.
- Income and adjustment information for each period, including your share of partnership or S-corporation income or loss.
- Your Oklahoma deductions, number of exemptions, and adjustments to Oklahoma adjusted gross income.
- Information about credits for each period, including credits carried over from a previous year.
- The Oklahoma Tax Table for line 13.
If you have out-of-state income, consult the individual income tax packet for the deduction and exemption proration instructions. For line 11 adjustments, the form refers to Schedule 511-C or Schedule 511-NR-C instructions.
How to file
- Complete Section Two, Part 1 of Form OW-8-P before completing this form.
- Enter your name as shown on your return and your Social Security number.
- Complete the installment calculations for each column. Transfer each required installment from line 24 to the applicable column on Form OW-8-P, Section Two, Part 2, line 9.
- Enclose both Form OW-8-P-SUP-I and Form OW-8-P with your return.
- Check the “annualized installment method” box on Form 511 or Form 511-NR.
Common mistakes
- Do not use this method for only some payment due dates. If you use it for one, you must use it for all.
- Do not start this form before completing Section Two, Part 1 of Form OW-8-P.
- If you had out-of-state income during a period, prorate deductions and exemptions before entering the total on line 10.
- Do not include withholding credits on line 14 or annualize any credit. Do annualize income or deductions used to figure a credit, and include credit carryovers.
- If you do not itemize, enter “0” on line 4 and skip to line 7.
- Remember to enclose both forms with your return and check the annualized installment method box.
Questions people ask
What periods do the four columns cover?
For tax year 2025, Column A covers January 1 through March 31; Column B, January 1 through May 31; Column C, January 1 through August 31; and Column D, January 1 through December 31.
How is the required installment selected?
Line 24 uses the smaller of line 19, the annualized income installment, or line 22, the regular installment adjusted for amounts saved using this method in earlier installments.
Should I use itemized deductions or the standard deduction on line 8?
If you would have itemized on your federal return based on annualized federal itemized deductions for that period, enter line 6. If you would have claimed the federal standard deduction for that period, enter line 7.
Are there special rules for part-year residents and nonresidents?
Yes. Taxpayers filing Form 511-NR calculate lines 1 through 12 as if all income were earned in Oklahoma, then follow the page 2 instructions to prorate the base tax for line 13. Those instructions also give special treatment for the Oklahoma child care/child tax credit.
Where can I find more information about annualization?
The form refers to the federal instructions for Form 2210 or Federal Publication 505 for additional information.