Recognized automaticallyPTET available

S-corp election in Idaho

In short

$20 minimum tax owed by virtually every Idaho S corp, plus a $10 Permanent Building Fund tax in limited cases, plus 5.3% tax on composite/ABE income and on built-in gains and excess net passive income.

Does Idaho recognize the federal S election?

Idaho automatically accepts the federal S election — the Idaho State Tax Commission states plainly: "Idaho accepts the federal approval of the S corporation election." There is no separate Idaho election form. One procedural catch that is easy to miss: you must attach a copy of the IRS approval letter (CP261) or the federal Form 2553 to your Form 41S the FIRST year you file in Idaho. The S corp then files Form 41S annually and issues Form ID K-1 to each shareholder.

Tax the entity still owes

Verified directly from Form 41S and its instructions (EFO00028 / EIN00098, revised 03-02-2026, tax year 2025). MINIMUM TAX (line 50, preprinted "20"): the instructions state "The minimum tax of $20 is required for each corporation: • That transacts business in Idaho • Is registered with the Idaho Secretary of State to do business in Idaho, or • An S corporation required to pay tax on excess net passive income or net recognized built-in gains." So a registered Idaho S corp owes the $20 even with zero income. If total computed tax exceeds $20 you strike the preprinted 20 and enter the real figure; tax before credits can never fall below $20. PERMANENT BUILDING FUND TAX (line 51): $10, owed by a corporation required to file an Idaho return — BUT the instructions carve out the ordinary pass-through case: "If all income/loss of the entity is distributed to or otherwise reported on the income tax return of another taxpayer, the PBF doesn't apply." An S corp electing ABE status must pay the $10 PBF for each Idaho NONRESIDENT member. A corporation protected by P.L. 86-272 owes no PBF. INCOME TAX (line 44): 5.3% of composite income (line 42) or ABE income (line 43). Idaho has no franchise or net-worth tax.

Registering for payroll

Register for an Idaho withholding account with the Idaho State Tax Commission and for unemployment insurance (SUTA) with the Idaho Department of Labor. Idaho uses a combined Idaho Business Registration (IBR) application that opens both the Tax Commission withholding account and the Department of Labor UI account in one submission; withholding is then filed and paid through TAP (tap.idaho.gov). Idaho's annual withholding reconciliation is Form 967, filed with the W-2s. Idaho has no state-run paid-leave payroll tax.

Annual filings

Form 41S (S Corporation Income Tax Return) — due the 15th day of the fourth month after the close of the tax year (April 15 for calendar-year filers). Form ID K-1 to each shareholder. Form PTE-12 if filing a composite return; Form PTE-NROA for nonresident owner agreements; Form 41ES for estimated payments and extension payments; Form ABE-ES for ABE estimated payments; Form 41ESR for underpayment interest. Payroll: periodic withholding returns via TAP plus Form 967 annual reconciliation; quarterly UI reports to the Idaho Department of Labor. Idaho Secretary of State annual report — filed through SOSBiz, no fee when filed on time; failure to file leads to administrative dissolution.

Pass-through entity tax

Yes — Idaho's PTET is the "Affected Business Entity" (ABE) election, made by checking the "Affected business entity" box in item 1 on the face of Form 41S (the choices are Regular / Composite / Affected business entity). Rate is 5.3% on ABE income (line 43 = apportioned business income + Idaho-allocated income − ABE NOL carryover). An ABE-electing S corp may claim an Idaho net operating loss at the entity level, which a non-electing S corp cannot (its NOL flows through). Estimated payments use Form ABE-ES; do not commingle PTE-01 payments. Special rules reduce credits and tax where the ABE has exempt entity members. Form 41S as revised 03-02-2026 still carries the ABE election, so the regime is active going into 2026.

The mistake owners make most often in Idaho

Assuming an Idaho S corp with no profit owes nothing and therefore skipping Form 41S. Idaho charges a $20 minimum tax to every corporation that transacts business in Idaho or is merely registered with the Secretary of State — a dormant or break-even S corp still must file and still owes $20, and non-filing accrues penalties and interest on top. The related first-year trap is forgetting to attach the IRS acceptance letter or Form 2553 to the first Form 41S.

Filing your federal Form 2553

Businesses operating in Idaho send Form 2553 to the IRS Ogden service center — fax 855-214-7520. Full address and filing checklist for Idaho.

Frequently asked questions

Does Idaho require a separate S-corporation election?

No. Idaho does not require a separate state election. Idaho automatically accepts the federal S election — the Idaho State Tax Commission states plainly: "Idaho accepts the federal approval of the S corporation election." There is no separate Idaho election form.

What tax does an S corporation pay in Idaho?

Where do I file Form 2553 from Idaho?

With the IRS Ogden service center. Fax 855-214-7520, or mail to Department of the Treasury, Internal Revenue Service, Ogden, UT 84201.

What is the most common S-corp mistake in Idaho?

Compare with other states: Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana.

Sources

File your Form 2553 correctly

Scorply completes your federal election and includes a Idaho guide in your packet, so you know exactly what else you owe here.

Start my Form 2553

Researched from official Idaho sources and verified July 30, 2026. State tax rules change. This is general information, not tax advice — confirm with the state or a CPA before you rely on it.