6220: Underpayment of Estimated Tax by Corporations (Revision 2019-01)
Alaska · Alaska DOR · Used for tax years 2024, 2025, 2026
Alaska Form 6220 is used by corporations to calculate underpayment of estimated tax. It lists net income tax, specified tax adjustments, prior-year tax, and required installments with their due dates.
Who files this form
Form 6220 is for corporations to compute underpayment of Alaska estimated tax. The supplied text does not state which corporations must file it.
If the amount on line 3 is less than $500, the form says to stop. No penalty is due, and you should not complete the rest of the form.
When it's due
For tax years 2024, 2025, and 2026, line 5 lists estimated tax installment due dates as the 15th day of the 4th, 6th, 9th, and 12th months of the tax year. Enter these dates in columns A through D.
The supplied text does not give a filing deadline for Form 6220.
What you'll need
Have the following information ready:
- The name shown on the return, EIN, and tax year.
- Net income tax and any amounts included for personal holding company tax, look-back interest, and Section 167(g) depreciation under the income forecast method.
- The tax shown on the previous year's return, if tax was reported, for line 4b.
If you use the annualized income installment method or adjusted seasonal installment method, the form requires an attached schedule.
Common mistakes
- Continuing after the line 3 stopping point: If line 3 is less than $500, do not complete the rest of the form. No penalty is due.
- Leaving out a required schedule: If you use the annualized income installment method or adjusted seasonal installment method, attach a schedule as directed next to the checkbox.
Questions people ask
How is line 3 calculated?
Add lines 2a through 2c and enter the total on line 2d. Then subtract line 2d from the net income tax on line 1.
What if line 3 is less than $500?
Stop without completing the rest of the form. The form states that no penalty is due.
Do I need to attach a schedule for an alternative installment method?
Yes. The form directs you to check the applicable box and attach a schedule if you use the annualized income installment method or adjusted seasonal installment method.
Does the form ask whether the corporation is a large corporation?
Yes. It includes a checkbox for when “large corporation” applies. The supplied text does not define that term.