N-220: Underpayment of Estimated Tax by Corporations and S Corporations (2025)
Hawaii · Hawaii DoTax · Used for tax years 2025
Hawaii Form N-220 calculates underpayments of estimated tax and any related penalty for corporations, S corporations and partnerships. It also includes Schedule A for calculating required installments using the annualized income or adjusted seasonal installment method.
Who files this form
Form N-220 covers underpayment of estimated tax by corporations, S corporations and partnerships. The form says to file it with Form N-20, N-30, N-35 or N-70NP.
Part I lists these reasons for filing:
- A corporation, S corporation or partnership uses the annualized income installment method.
- A corporation or S corporation uses the adjusted seasonal installment method.
- A “large corporation” computes its first installment using the prior year's tax.
If none of these reasons applies, the form directs you to continue to Part II. If line 3 is less than $500, do not complete or file Form N-220. No underpayment penalty is owed.
When it's due
For tax year 2025, line 6 gives these estimated tax installment due dates:
- The 20th day of the 4th month of the tax year.
- The 20th day of the 6th month of the tax year.
- The 20th day of the 9th month of the tax year.
- The 20th day of the 1st month after the tax year closes.
For the penalty calculation, line 18 uses the date each installment was paid or the 20th day of the 4th month after the tax year closes, whichever is earlier.
The form does not print a separate filing deadline for Form N-220.
What you'll need
Have the information needed for the form's entries:
- Your name as shown on the tax return and Federal Employer I.D. Number.
- Your 2025 return information for total tax, credits and any look-back interest for completed long-term contracts.
- Your 2024 income tax return if completing line 4. The form cautions you to read the separate instructions before using this line.
- Estimated tax payment and credit amounts for each period, plus installment payment dates.
If using Schedule A, you also need taxable income, tax and credit information for the applicable periods. The adjusted seasonal method asks for income information for tax years beginning in 2022, 2023, 2024 and 2025.
How to file
Attach Form N-220 to your tax return. The form lists Forms N-20, N-30, N-35 and N-70NP as the returns it accompanies.
Enter the total underpayment penalty from line 21 on the applicable return:
- Form N-20, line 21.
- Form N-30, line 17.
- Form N-35, line 24.
- Form N-70NP, line 23.
The supplied form does not provide a mailing address or e-file directions.
Common mistakes
- Using line 4 without checking the instructions. The form specifically cautions you to read the separate instructions before entering the 2024 tax amount.
- Using the adjusted seasonal method without meeting its condition. Schedule A warns that this method may be used only if the base period percentage for any 6 consecutive months is at least 70%.
- Working across columns too soon. Complete Part II, lines 9 through 15, for one column before moving to the next. Schedule A gives the same reminder for lines 32 through 38.
- Treating Schedule A's large-corporation calculation as the standard calculation. The note on line 35 directs large corporations to the instructions for line 7 for the amount to enter.
Questions people ask
Do I need to complete the form if line 3 is less than $500?
No. The form says not to complete or file it, and no underpayment penalty is owed.
What if there are no underpayments on line 14?
If there are no entries on line 14, no penalty is owed.
What credits do S corporations and partnerships enter on line 2a?
S corporations and partnerships must enter zero on line 2a.
How is the underpayment penalty calculated?
For each installment column, line 20 multiplies the number of months on line 19 by .00667 and by the underpayment on line 16. Line 21 adds the four results. The form refers you to the separate instructions for counting the months.