Form 41ES — Business Income Estimated Tax Payment / Extension

# Form 41ES - Worksheets

Business Income Tax Payments
Use the worksheet in Part A to compute your business estimated tax payments.
Use the worksheet in Part B to determine if you need to make an extension of time payment.
If you're making an Affected Business Entity Election payment before filing a return, use Form ABE-ES.
A. Business Estimated Tax Payments Worksheet

1. 2025 estimated Idaho taxable income … 1.
2. Income tax on estimated Idaho taxable income. Multiply line 1 by 5.3% … 2.
3. Permanent building fund tax ($10 or, if a combined report, multiply $10 by the number of corporations required to file an Idaho income tax return) … 3.
4. Tax from recapture of business income tax credits. See Form 44, Part II, for a complete list ... 4.
5. Total income tax. Add lines 2 through 4 … 5.
6. Estimated income tax credits … 6.
7. 2025 estimated income taxes payable. Line 5 minus line 6 … (If the amount is less than $500, stop here. You aren't required to make estimated tax payments.) 7.
8. Multiply line 7 by 90% … 8.
9. Idaho total tax less the total of the fuels tax, sales/use tax, tax from recapture of qualified investment exemption (QIE), the tax reimbursement incentive credit from the 2024 tax return, and the ABE tax paid by another entity from Form 41S, line 61 or Form 65, line 57 … 9.
10. Estimated tax payments. Multiply the smaller of lines 8 or 9 by 25%. This is the amount of each estimated tax payment … 10.

B. Extension of Time Payment Worksheet Yes No

1. Did you file a 2024 tax return? … 1.
2. If yes, enter the total tax less the total of the fuels tax, sales/use tax, tax from recapture of QIE, and the tax reimbursement incentive credit from the 2024 tax return … 2.
3. 2025 estimated income tax due less estimated income tax credits. (Estimated tax due includes the $20 minimum tax, the $10 permanent building fund tax, and tax from recapture of business income tax credits.) See instructions … 3.
4. Multiply line 3 by 80% … 4.
5. If you answered yes to the question on line 1, enter the smaller amount from line 2 or 4.

If you answered no, enter the amount from line 4 … 5.

1. Estimated tax payments, tentative payments, and the ABE tax paid by another entity from Form 41S, line 61 or Form 65, line 57 … 6.
2. Payment. Line 5 minus line 6. If $50 or less, a payment isn't required … 7.

Pay online at tax.idaho.gov/epay (don't send voucher). Sending check and/or money order? Use voucher below.

# Form 41ES - Voucher

Estimated Tax Payment/Extension of Time Payment
Business Income Tax
Mail to:
PO Box 83784
Boise ID 83707-3784
EFO00026 09-18-2025

# Form 41ES - Instructions

Business Income Tax Payments
A. Business Estimated Tax Payments
Who Must Make Estimated Tax Payments
A corporation must make estimated tax payments to the Tax Commission if it's required to make estimated tax payments to the Internal Revenue Service and will have an Idaho income tax liability of $500 or more. Estimated tax payments aren't required if the corporation wasn't required to file an Idaho return the previous tax year.
If you received personalized payment vouchers (Form 41EST), use the appropriate voucher for each filing period. If any of the preprinted information is incorrect, draw a line through it, and enter the correct information. Check the mailing address change box on the voucher if there's a change in your mailing address. If you don't have a preprinted form, use the Form 41ES, available at tax.idaho.gov.

# Estimated Tax Payments

Each estimated tax payment must be 25% of the lesser of:

• 100% of the corporation's income tax for 2024
• 90% of its income tax for 2025

Don't include:

• Fuels tax due
• Sales/use tax due
• Fuels tax refunds
• Tax from the recapture of qualified investment exemption (QIE)
• The tax reimbursement incentive credit
• ABE tax paid by another entity from Form 41S, line 61 or Form 65, line 57 For corporations, the tax required to be reported is defined as Idaho taxable income multiplied by the appropriate tax rate, plus the permanent building fund tax, plus tax from recapture of business income tax credits, minus allowable income tax credits. A corporation making estimated tax payments in a year following the revocation of subchapter S status will use $20 as the tax amount required to be reported on the prior year's return.

For S corporations, estimated tax payments are computed on the Idaho tax due to net recognized built-in gains and excess net passive income.
EIN00073 09-18-2025
Estimated tax payments aren't required on the tax due on income you report for individual shareholders.

# Computation of Estimated Tax Payments

The Form 41ES worksheet allows you to compare the income tax on last year's return with the anticipated income tax for the current year. Use the smaller of the two amounts to determine the estimated tax payment for each period. If your estimated tax payments are based on 90% of the income tax required to be paid on the current year's return and the anticipated income tax for the current year is revised, use the revised amount to recompute any remaining estimated tax payments.

# Due Dates

For calendar year taxpayers, estimated tax payments are due by the 15th day of April, June, September, and December. For fiscal year taxpayers, estimated tax payments are due by the 15th day of the 4th, 6th, 9th, and 12th months of the tax year.
The due dates for the federal and Idaho estimated tax payments are the same. If the due date is on a Saturday, Sunday, or legal holiday, the payment is due on the next regular business day.

# Underpayment of Estimated Tax

Interest is due on the difference between the amount of estimated tax payment required to be made on each voucher and the amount of estimated tax payment actually made. Interest is computed from the due date of the estimated payment until the required amount is paid or until the due date of the return, whichever comes first. The interest rate for 2025 is 6%. The interest rate for 2026 is 6%.
Use Form 41ESR to determine the amount of any underpayments of tax and interest due when you file your return.

Overpayment of Estimated Tax
If your estimated tax payments are more than the tax you owe, you'll receive a refund after filing your return.
You may apply all or part of the excess to next year's estimated tax by designating the amount on

# Form 41, Corporation Income Tax Return or Form

41S, S Corporation Income Tax Return.

# Annualized Income and Estimated Tax Payments

# Short Tax Year

# General Information