How to Form a Corporation in Idaho
By Edmond Hui · Facts verified July 29, 2026 against primary state sources
Edmond Hui · Founder, MyStateLLC
Edmond Hui is a software engineer and serial entrepreneur based in New York who has founded multiple online businesses across e-commerce, media, and information publishing. Before transitioning into tech, he spent years as a commercial real estate professional closing deals totaling over 100,000 square feet, giving him firsthand experience with business formation and entity structuring. He built MyStateLLC to provide the free, state-specific LLC guidance he wished existed when forming his own companies.
What you file in Idaho
Incorporation filing
| Document | Articles of Incorporation (filed online via SOSBiz; $100 if typed/online, $120 if handwritten/not typed) |
| Fee | $100 |
| Recurring report | Annual Report (filed online through SOSBiz) — every year, $0 |
| First report due | By the last day of the anniversary month of incorporation each year (no fee) |
This page covers the state filing and the charges that follow it. For the procedural side — name availability, registered agent, bylaws and the federal EIN — see the formation guide and how to get an EIN, both of which apply to corporations as well as LLCs.
What it costs to incorporate and stay filed
State filing charges only. Corporate income tax and franchise tax are excluded — both depend on income or net worth, so no flat figure would be true for every corporation.
| Charge | Amount | How often |
|---|---|---|
| Articles of Incorporation (filed online via SOSBiz; $100 if typed/online, $120 if handwritten/not typed) | $100 | One time |
| Annual Report (filed online through SOSBiz) | $0 | Every year |
| First-year state filing charges | $100 | — |
| Five-year state filing charges | $100 | — |
Idaho is the 21st cheapest of 49 states on the incorporation filing fee alone. Nationally the fee runs from $35 in Montana to $300 in Texas, averaging $113.06. It is a one-off charge, so over five years it is usually outweighed by the recurring report fee and any annual franchise or minimum tax.
States that are cheaper to incorporate in
A cheaper filing fee elsewhere rarely saves money if you actually operate in Idaho. Every state sets its own threshold for what counts as transacting business, and where that threshold is met an out-of-state corporation is generally required to register as a foreign corporation — which would mean fees in both states rather than one. Whether it applies to you depends on facts this page cannot see, so check foreign qualification in Idaho before incorporating elsewhere to save on the filing fee.
Idaho corporation vs Idaho LLC
State filing charges only. Corporate income tax and franchise tax are excluded because both depend on income or net worth, so no flat figure exists for either entity.
| Corporation | LLC | |
|---|---|---|
| Formation filing fee | $100 | $100 |
| Report cadence | Every year | Every year |
| Report fee | $0 | $0 |
Both entities cost $100 to file in Idaho, so the filing fee is not a reason to pick one over the other.
Full Idaho LLC cost breakdown · LLC vs C-corp explained · LLC vs S-corp explained
State taxes a Idaho corporation pays
Corporate income tax
| Applies | Yes |
| Rate | 5.3% flat (tax year 2025, per Form 41 line 38) |
| Minimum tax | $20 |
Franchise or gross-receipts tax
No franchise tax in Idaho. Corporations filing Form 41 also pay a $10 permanent building fund tax (Form 41 line 44), and the income tax has a $20 minimum per corporation.
The $20 minimum tax is deliberately left out of the filing-charge totals on this page. A minimum tax is owed to the state tax authority on a tax return, not to the business filing office — but unlike an income-based tax it is a floor, so treat it as a recurring cost of keeping the corporation alive here.
What these totals leave out: the filing-charge figures on this page are what you pay the business filing office. They exclude corporate income tax and any franchise or gross-receipts tax, because both depend on income, net worth or receipts. The section above sets out what Idaholevies — or that it levies neither. Where a state's franchise tax carries a flat minimum, that minimum is an unavoidable annual cost these totals do not include, and over five years it can be the larger number.
C-corp return: Form 41 (Corporation Income Tax Return)
Electing S-corporation status in Idaho
Idaho follows the federal S election. Full Idaho S-corporation election guide.
Frequently Asked Questions
Where these numbers come from
This page covers the state filing required to incorporate in Idaho and the charges that follow it. Every figure was checked against Idaho's own published sources on July 29, 2026— the state business filing agency's fee schedule, the governing statute, and where a state tax applies, the state Department of Revenue. Commercial formation-service pages were used as leads only and are never cited. Anything the review could not confirm from an official source is left blank on this page rather than filled with an estimate.
Corporate income tax and franchise tax are quoted as the state publishes them, as rate schedules and thresholds, and are excluded from every dollar total here. They depend on income or net worth, so there is no flat figure that would be true for every corporation.