Idaho LLC annual report & franchise tax deadlines 2026-2027
Every recurring Idaho filing for LLCs, S corps and C corporations — due dates, fees and the official source for each. Last verified Oct 21, 2026.
LLC
| Report | Annual Report Partly confirmed — verify |
|---|---|
| Due | By the last day of the formation month each year |
| State fee | No fee |
| How often | annual |
Corporation (C & S corp)
| Report | Annual Report Partly confirmed — verify |
|---|---|
| Due | By the last day of the incorporation month each year |
| State fee | No fee |
| How often | annual |
Franchise & entity-level taxes
| No separate statewide franchise or entity-level tax listed for this state. |
State income & estimated tax
| Corporate income tax | Yes |
|---|---|
| C corp return | Apr 15 |
| Partnership / S corp return | Apr 15 (Form 65 / 41S) |
| Corporate estimates | Apr 15, Jun 15, Sep 15, Dec 15 (follows the federal corporate schedule) |
General pattern — verify Calendar-year pattern; confirm with the revenue department.
Sales tax
Filing frequency (monthly, quarterly or annual) is assigned by the state based on your tax liability. Returns are generally due the 20th of the month after the reporting period.
General pattern — verify Your assigned frequency and due day appear in your state tax account.
IRS disaster postponements in Idaho
No active IRS disaster postponements for Idaho as of Oct 21, 2026. See all deadline changes.
Your Idaho calendar
Add your formation month/year to date anniversary-based reports. Calendar-year filers; weekend and federal-holiday dates roll to the next business day.
Upcoming deadlines
Not tax advice — verify each date with the linked source. Fiscal-year filers' dates differ.
Tools that help you stay compliant
Partner placements — placeholders, not yet live. Disclosed as sponsored when active.
Partner link (placeholder)
Partner link (placeholder)
Partner link (placeholder)
Idaho deadline FAQ
When is the Idaho LLC annual report due?
By the last day of the formation month each year.
How much does the Idaho LLC annual report cost?
State fee: No fee.
When is the Idaho corporation annual report due?
By the last day of the incorporation month each year. Fee: No fee. S corporations file the same report as other corporations.
Does Idaho have a franchise tax or annual LLC tax?
We don't list a separate statewide franchise or entity-level tax for Idaho. Income and sales taxes may still apply.
When are Idaho business income tax returns due?
C corporations: Apr 15. Pass-through entities (partnerships, S corps): Apr 15 (Form 65 / 41S). These are general calendar-year patterns — confirm with the state revenue department.
How often do I file Idaho sales tax?
Filing frequency (monthly, quarterly or annual) is assigned by the state based on your tax liability. Returns are generally due the 20th of the month after the reporting period.
What happens if I miss a Idaho deadline?
Most states charge a late fee or penalty and interest, and an entity that keeps missing its annual report can lose good standing and eventually be administratively dissolved. Check the official source for the exact penalty and reinstatement steps.
Official sources
- https://sos.idaho.gov/business-resources/business-faq/
- https://tax.idaho.gov
- https://legislature.idaho.gov/statutesrules/idstat/Title30/T30CH21/SECT30-21-213/
- https://sosbiz.idaho.gov/
- https://legislature.idaho.gov/statutesrules/idstat/Title30/T30CH21/SECT30-21-214/
- https://legislature.idaho.gov/statutesrules/idstat/Title30/T30CH21/SECT30-21-601/
- https://legislature.idaho.gov/statutesrules/idstat/Title30/T30CH21/SECT30-21-602/
- https://legislature.idaho.gov/statutesrules/idstat/Title30/T30CH21/SECT30-21-603
- https://sos.idaho.gov/business-forms/
Federal dates: IRS Publication 509. Disaster relief: IRS tax relief in disaster situations.
Get deadline alerts for your state
One short email a week: what's due in the next 30 days, plus any IRS or state deadline changes. Free, unsubscribe anytime.