OW-8-P-SUP-C: 2025 Form OW-8-P-SUP-C Annualized Income Installment Method Corporations and Trusts (2025)
Oklahoma · Oklahoma Tax Commission · Used for tax years 2025
Form OW-8-P-SUP-C calculates required Oklahoma estimated income tax installments using the annualized income installment method for corporations, S corporations, exempt organizations, partnerships, and trusts. It uses income for specified periods, Oklahoma income tax, and credits
Who files this form
Form OW-8-P-SUP-C is Oklahoma’s annualized income installment form for corporations, S corporations, exempt organizations, partnerships, and trusts.
If you use this form for any payment due date, you must use it for all payment due dates. Use Schedule One for corporations and Schedule Two for trusts.
Corporations may compute estimated taxes on an annualized basis only for a taxable year of 12 months.
What you'll need
Have the following ready to complete the form:
- Form OW-8-P, with Section Two, Part 1 completed.
- Your name as shown on your return and your Federal Employer Identification Number.
- Oklahoma taxable income for each annualization period.
- Oklahoma refundable and nonrefundable credit amounts.
- For trusts, the exemption amount shown on the tax return and the individual income tax table.
How to file
Provide Form OW-8-P-SUP-C and Form OW-8-P with your tax return.
Transfer each required installment from Schedule One, line 15, or Schedule Two, line 17, to the applicable column on Form OW-8-P, Section Two, Part 2, line 9.
The supplied form does not give a mailing address or e-file instructions.
Common mistakes
- Do not use this form for only some payment due dates. If you use it for one, you must use it for all.
- Complete Form OW-8-P, Section Two, Part 1 before completing this form.
- Work through one column at a time: complete lines 9–15 on Schedule One or lines 11–17 on Schedule Two before moving to the next column.
- Corporations may not use the annualization provisions in IRC Sections 6655(e)(2)(C) and 6655(e)(3).
- Corporations may use annualized estimated tax calculations only for a 12-month taxable year.
- Include both this form and Form OW-8-P with your return.
Questions people ask
Which schedule should I use?
Use Schedule One for corporations and Schedule Two for trusts.
How does the form determine each required installment?
The schedule selects the smaller of the annualized income installment or the regular installment, increased by the amount saved by using the annualized method for earlier installments.
What income periods does Schedule One use?
For corporations, Columns A and B both use the first 3 months. Column C uses the first 6 months, and Column D uses the first 9 months.
How do trusts account for exemptions?
Enter Oklahoma taxable income without exemptions on Schedule Two, line 1. Enter the exemption amount shown on the tax return on line 4, then subtract it from annualized taxable income on line 3.
Where does the form point me for more information?
For corporations, it refers to the instructions for Federal Form 2220. For trusts, it refers to the instructions for Federal Form 2210 or Federal Publication 505.