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Idaho business tax extension

Idaho extends Form 41 automatically by 6 months, with no extension request and no federal extension needed. The federal extension is Form 7004, due for calendar-year corporations and for partnerships and S corporations. In general, an extension gives you more time to file, not more time to pay.

Last updated · From Idaho's own forms, instructions and laws, cited below

Does Idaho accept the federal extension?

Idaho extends the return automatically, with no extension request and no federal extension needed.

Idaho's rules for each business return, as its own instructions and laws state them:

Corporations

Return
Form 41, Corporation Income Tax Return
Due date
The 15th day of the 4th month after the tax year ends (April 15 for a calendar year)
Extension
Idaho extends the return automatically, with no extension request and no federal extension needed. The extension holds only if, by the original due date, the business has paid at least 80% of the current year's tax or 100% of the total tax on last year's return. No payment is needed if $50 or less is owed.
Extension length
6 months
Extended due date
The 15th day of the 10th month after the tax year ends (October 15 for a calendar year)
Payment
The tax is due by the original due date, even with an extension. To pay with the extension: Form 41ES, Estimated Tax Payment/Extension of Time Payment, or online at tax.idaho.gov/epay.

S corporations

Return
Form 41S, S Corporation Income Tax Return
Due date
The 15th day of the 4th month after the tax year ends (April 15 for a calendar year)
Extension
Idaho extends the return automatically, with no extension request and no federal extension needed. The extension holds only if, by the original due date, the business has paid at least 80% of the current year's tax or 100% of the total tax on last year's return. No payment is needed if $50 or less is owed.
Extension length
6 months
Extended due date
The 15th day of the 10th month after the tax year ends (October 15 for a calendar year)
Payment
The tax is due by the original due date, even with an extension. To pay with the extension: Form 41ES, Estimated Tax Payment/Extension of Time Payment, or online at tax.idaho.gov/epay.

Partnerships

Return
Form 65, Partnership Return of Income
Due date
The 15th day of the 4th month after the tax year ends (April 15 for a calendar year)
Extension
Idaho extends the return automatically, with no extension request and no federal extension needed. The extension holds only if, by the original due date, the business has paid at least 80% of the current year's tax or 100% of the total tax on last year's return. No payment is needed if $50 or less is owed.
Extension length
6 months
Extended due date
The 15th day of the 10th month after the tax year ends (October 15 for a calendar year)
Payment
The tax is due by the original due date, even with an extension. To pay with the extension: Form 41ES, Estimated Tax Payment/Extension of Time Payment, or online at tax.idaho.gov/epay.

Estates and trusts

Return
Form 66, Idaho Fiduciary Income Tax Return
Due date
The 15th day of the 4th month after the tax year ends (April 15 for a calendar year)
Extension
Idaho extends the return automatically, with no extension request and no federal extension needed. The extension holds only if, by the original due date, the business has paid at least 80% of the current year's tax or 100% of the total tax on last year's return. No payment is needed if $50 or less is owed.
Extension length
6 months
Extended due date
The 15th day of the 10th month after the tax year ends (October 15 for a calendar year)
Payment
The tax is due by the original due date, even with an extension. To pay with the extension: Form 41ES, Estimated Tax Payment/Extension of Time Payment, or online at tax.idaho.gov/epay.

When a due date in Idaho falls on a weekend or legal holiday, it moves to the next business day. Idaho's holidays can differ from the federal ones, so a rule not tied to a federal date is given without a computed date.

When is the federal business extension due?

Corporations, S corporations, partnerships, multi-member LLCs, estates and trusts extend their federal return with Form 7004, filed by the return's original due date. The extension is automatic: no reason is needed and the IRS doesn't approve it. We e-file it for a flat $9.95. These are the 2027 dates for calendar-year 2026 returns:

Federal extension deadlines for calendar-year 2026 returns
ReturnFile the extension byExtended to
Form 1065 Partnerships & multi-member LLCs, Form 70046 months
Form 1120-S S corporations (and LLCs taxed as S corps), Form 70046 months
Form 1120 C corporations (and LLCs taxed as C corps), Form 70046 months
Form 1041 Estates & trusts, Form 70045½ months
Form 990, 990-EZ, 990-PF Tax-exempt organizations & private foundations, Form 8868May 15, 2027 is a Saturday6 months

Federal dates follow the IRS rule: a deadline on a weekend or legal holiday moves to the next business day. A fiscal-year business counts from its own year-end; see the fiscal-year deadline guide.

Tax-exempt organizations extend the 990 series with Form 8868, not Form 7004. Each return needs its own extension, so extending a business return does not extend its owners' personal returns.

Does an extension give more time to pay?

No. A federal extension moves the filing deadline only: tax owed is due by the original due date, and the IRS charges interest and the late-payment penalty on anything paid after it. Idaho's instructions say the same for its returns: a Idaho extension doesn't move the payment deadline. More in does an extension give you more time to pay?

Where are Idaho's forms and instructions?

On the Idaho State Tax Commission website, which has the current forms, instructions and online services. The rules on this page are summarized from the sources below. We e-file the federal extension; the Idaho return and any Idaho extension request go to the state.

Idaho extension FAQ

Does Idaho accept the federal business tax extension?

Idaho extends the return automatically, with no extension request and no federal extension needed. The extension is 6 months. The extension holds only if, by the original due date, the business has paid at least 80% of the current year's tax or 100% of the total tax on last year's return. No payment is needed if $50 or less is owed.

When is the Idaho Form 41 due?

The 15th day of the 4th month after the tax year ends (April 15 for a calendar year).

Does a Idaho extension give more time to pay?

No. The tax is due by the original due date, even with an extension. To pay with the extension: Form 41ES, Estimated Tax Payment/Extension of Time Payment, or online at tax.idaho.gov/epay.

Does a Idaho business still need a federal extension?

Yes, to get more time for its federal return: Form 7004, filed by April 15, 2027 for a calendar-year corporation or March 15, 2027 for a partnership or S corporation. Idaho's own extension is automatic.

Sources

Filing a federal business extension this season?

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