Idaho business filing dates, 2027
State-level due dates for businesses filing in Idaho. Every line links to the official page it came from, with the date that page was read. Where no official source has been verified, the line says so instead of showing a date.
Add to Google CalendarAdd to Apple or OutlookDownload .ics38 dated lines in the calendar file · sources last read 2026-09-23
Coverage · 3 of 6 fully dated
Income / franchise tax return
1 dateThe annual return for the business’s tax year, and in franchise-tax states the report that keeps the entity in good standing. Which form and which date depend on the entity type and the tax year. Where the source grants an extension, it extends the time to file; the source says whether it also extends the time to pay.
| Obligation | Applies to | Due rule | 2027 dates | Source · retrieved |
|---|---|---|---|---|
Corporation income tax return (Form 41)calendar-year C corporationSource text“File your Idaho income tax return on or before the 15th day of the fourth month following the close of your tax year. For a calendar year filer, this is April 15. If the last day for filing a return falls on a Saturday, Sunday, or legal holiday, the return is on time if you file it on the next business day.”verbatim · tax.idaho.gov · retrieved 2026-09-23 “Individuals, corporations, pass-through entities, and fiduciaries can file income tax returns up to six months from the original due date with a valid extension. A valid extension means you can avoid a penalty for filing late. There aren’t any extensions allowing you to pay late. You’ll owe interest on any tax not paid by the original due date.”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toA corporation files its Idaho return by the 15th day of the 4th month after its tax year closes (April 15 for calendar-year filers). A Saturday, Sunday or legal-holiday date moves to the next business day. A valid extension allows filing up to six months later, but not paying late. | Due ruleForm 41: 15th day of the 4th month after the tax year endsA date on a weekend moves to the next business day; state holidays are not compiled. | 2027 dates
State legal holidays are not compiled: if this date is a state holiday, the deadline moves to the next business day. | Source · retrievedtax.idaho.gov/taxes/income-tax/business-income/guides-for-certain-businesses/income-tax-for-corporations/ (official source, opens in a new tab)retrieved tax.idaho.gov/taxes/income-tax/extension/ (official source, opens in a new tab)retrieved |
Estimated tax
UnsupportedInstallments paid during the year toward the year’s tax. Whether a business must pay them depends on its expected liability, which this page cannot know; the lines show when installments fall due for those who must.
Why no dates: No official source confirmed yet for Idaho's estimated tax payment due dates.
| Obligation | Applies to | Due rule | 2027 dates | Source · retrieved |
|---|---|---|---|---|
| Estimated tax | Applies toShown once verified | Due ruleUnsupported | 2027 datesNo official source confirmed yet for Idaho's estimated tax payment due dates. | Source · retrievedNo verified source on file |
Withholding
18 datesReturns and deposits of income tax withheld from employees’ wages. The agency assigns each employer a deposit frequency, usually from its past liability, so the dates differ by frequency.
| Obligation | Applies to | Due rule | 2027 dates | Source · retrieved |
|---|---|---|---|---|
Form 910 withholding paymentmonthly withholding filerSource text“Form 910 monthly filers Due the 20th of the month following the payment period”verbatim · tax.idaho.gov · retrieved 2026-09-23 “Form 910 quarterly filers Due the last day of the month following the end of a quarter”verbatim · tax.idaho.gov · retrieved 2026-09-23 “Form 910 annual filers Due the last day of January”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toBy the filing cycle the Tax Commission assigns (the preparer declares it): monthly filers by the 20th of the next month; quarterly filers by the last day of the month after the quarter; annual filers by the last day of January. Semimonthly filers are not dated here. A weekend or state-holiday date moves to the next business day. | Due ruleForm 910: 20th day of the month after the month endsA date on a weekend moves to the next business day; state holidays are not compiled. | 2027 dates
State legal holidays are not compiled: if this date is a state holiday, the deadline moves to the next business day. | Source · retrievedtax.idaho.gov/taxes/income-tax/withholding/withholding-due-dates/ (official source, opens in a new tab)retrieved |
Form 910 withholding paymentannual withholding filerSource text“Form 910 monthly filers Due the 20th of the month following the payment period”verbatim · tax.idaho.gov · retrieved 2026-09-23 “Form 910 quarterly filers Due the last day of the month following the end of a quarter”verbatim · tax.idaho.gov · retrieved 2026-09-23 “Form 910 annual filers Due the last day of January”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toBy the filing cycle the Tax Commission assigns (the preparer declares it): monthly filers by the 20th of the next month; quarterly filers by the last day of the month after the quarter; annual filers by the last day of January. Semimonthly filers are not dated here. A weekend or state-holiday date moves to the next business day. | Due ruleForm 910: January 31 of the year after the calendar year endsA date on a weekend moves to the next business day; state holidays are not compiled. | 2027 dates
State legal holidays are not compiled: if this date is a state holiday, the deadline moves to the next business day. | Source · retrievedtax.idaho.gov/taxes/income-tax/withholding/withholding-due-dates/ (official source, opens in a new tab)retrieved |
Form 910 withholding paymentquarterly withholding filerSource text“Form 910 monthly filers Due the 20th of the month following the payment period”verbatim · tax.idaho.gov · retrieved 2026-09-23 “Form 910 quarterly filers Due the last day of the month following the end of a quarter”verbatim · tax.idaho.gov · retrieved 2026-09-23 “Form 910 annual filers Due the last day of January”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toBy the filing cycle the Tax Commission assigns (the preparer declares it): monthly filers by the 20th of the next month; quarterly filers by the last day of the month after the quarter; annual filers by the last day of January. Semimonthly filers are not dated here. A weekend or state-holiday date moves to the next business day. | Due ruleForm 910: last day of the month after the quarter endsA date on a weekend moves to the next business day; state holidays are not compiled. | 2027 dates
State legal holidays are not compiled: if this date is a state holiday, the deadline moves to the next business day. | Source · retrievedtax.idaho.gov/taxes/income-tax/withholding/withholding-due-dates/ (official source, opens in a new tab)retrieved |
Form 967 reconciliation and W-2sSource text“Form 967 and W-2s are due by the last day of January, and 1099s are due by the last day of February.”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toAn employer the preparer attests withholds Idaho income tax files the Form 967 annual reconciliation and W-2s by the last day of January. A weekend or state-holiday date moves to the next business day. | Due ruleForm 967 and W-2s: January 31 of the year after the calendar year endsA date on a weekend moves to the next business day; state holidays are not compiled. | 2027 dates
State legal holidays are not compiled: if this date is a state holiday, the deadline moves to the next business day. | Source · retrievedtax.idaho.gov/taxes/income-tax/withholding/withholding-filing/filing-information-returns-1099s-w-2s/ (official source, opens in a new tab)retrieved |
Unemployment insurance
UnsupportedEmployer contribution and wage reports for unemployment insurance: the state program, and FUTA at the federal level.
Why no dates: No official source confirmed yet for Idaho's unemployment insurance report due dates.
| Obligation | Applies to | Due rule | 2027 dates | Source · retrieved |
|---|---|---|---|---|
| Unemployment insurance | Applies toShown once verified | Due ruleUnsupported | 2027 datesNo official source confirmed yet for Idaho's unemployment insurance report due dates. | Source · retrievedNo verified source on file |
Sales and use tax
19 datesReturns for sales and use tax collected under a permit. The agency assigns each permit holder a filing frequency; the dates differ by frequency.
| Obligation | Applies to | Due rule | 2027 dates | Source · retrieved |
|---|---|---|---|---|
Sales and use tax return (Form 850), quarterly, semiannual or annualannual filerSource text“Retailers who owe less than $750 tax per quarter pay their taxes quarterly. These taxes are due within 20 days after the end of the quarter.”verbatim · tax.idaho.gov · retrieved 2026-09-23 “Semiannually or annually. If you’re a distributor or a wholesaler with only a few sales, you can apply to file returns and forward taxes every six months, or once per year. Taxes paid every six months are due by July 20 and January 20. Taxes paid once per year are due by January 20.”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toRetailers owing less than $750 a quarter pay within 20 days after the quarter; semiannual filers by July 20 and January 20; annual filers by January 20. The source states a weekend rule only for monthly filers, so these dates are shown as stated. | Due ruleForm 850: 20th day of the month after the calendar year ends | 2027 dates
| Source · retrievedtax.idaho.gov/taxes/sales-use/stfiling/ (official source, opens in a new tab)retrieved |
Sales and use tax return (Form 850), quarterly, semiannual or annualsemiannual filerSource text“Retailers who owe less than $750 tax per quarter pay their taxes quarterly. These taxes are due within 20 days after the end of the quarter.”verbatim · tax.idaho.gov · retrieved 2026-09-23 “Semiannually or annually. If you’re a distributor or a wholesaler with only a few sales, you can apply to file returns and forward taxes every six months, or once per year. Taxes paid every six months are due by July 20 and January 20. Taxes paid once per year are due by January 20.”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toRetailers owing less than $750 a quarter pay within 20 days after the quarter; semiannual filers by July 20 and January 20; annual filers by January 20. The source states a weekend rule only for monthly filers, so these dates are shown as stated. | Due ruleForm 850 (January–June): July 20 of the year the calendar year begins; Form 850 (July–December): January 20 of the year after the calendar year begins | 2027 dates
| Source · retrievedtax.idaho.gov/taxes/sales-use/stfiling/ (official source, opens in a new tab)retrieved |
Sales and use tax return (Form 850), quarterly, semiannual or annualquarterly filerSource text“Retailers who owe less than $750 tax per quarter pay their taxes quarterly. These taxes are due within 20 days after the end of the quarter.”verbatim · tax.idaho.gov · retrieved 2026-09-23 “Semiannually or annually. If you’re a distributor or a wholesaler with only a few sales, you can apply to file returns and forward taxes every six months, or once per year. Taxes paid every six months are due by July 20 and January 20. Taxes paid once per year are due by January 20.”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toRetailers owing less than $750 a quarter pay within 20 days after the quarter; semiannual filers by July 20 and January 20; annual filers by January 20. The source states a weekend rule only for monthly filers, so these dates are shown as stated. | Due ruleForm 850: 20 days after the quarter ends | 2027 dates
| Source · retrievedtax.idaho.gov/taxes/sales-use/stfiling/ (official source, opens in a new tab)retrieved |
Sales and use tax return (Form 850)Source text“Most retailers file returns every month. They forward the tax due for each month by the 20th day of the following month. If the 20th falls on a weekend or holiday, the return and payment are due on the next workday. For example, the taxes you collected in July are due by August 20.”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toMonthly filers pay by the 20th of the following month; a 20th on a weekend or holiday moves to the next workday. Quarterly, semiannual and annual filers are on their own line. | Due ruleForm 850: 20th day of the month after the month endsA date on a weekend moves to the next business day; state holidays are not compiled. | 2027 dates
State legal holidays are not compiled: if this date is a state holiday, the deadline moves to the next business day. | Source · retrievedtax.idaho.gov/taxes/sales-use/stfiling/ (official source, opens in a new tab)retrieved |
Annual report
UnsupportedThe annual or biennial report an entity files with the Secretary of State (or its equivalent) to stay in good standing. Some are keyed to the month the entity was formed.
Why no dates: No official source confirmed yet for Idaho's annual report due date.
| Obligation | Applies to | Due rule | 2027 dates | Source · retrieved |
|---|---|---|---|---|
| Annual report | Applies toShown once verified | Due ruleUnsupported | 2027 datesNo official source confirmed yet for Idaho's annual report due date. | Source · retrievedNo verified source on file |
Information returns
UnsupportedForms reporting payments to others — W-2s to employees, 1099s to contractors — furnished to the recipients and filed with the agency.
Why no dates: Not yet verified against its official source; no date is shown until it is.
| Obligation | Applies to | Due rule | 2027 dates | Source · retrieved |
|---|---|---|---|---|
| Forms 1099 to Idaho | Applies toShown once verified | Due ruleUnsupported | 2027 datesNot yet verified against its official source; no date is shown until it is. | Source · retrievedNo verified source on file |
Due-date rules
no fixed dateThe conventions other lines cite: how a date on a weekend or holiday moves, and how a disaster declaration postpones deadlines.
| Obligation | Applies to | Due rule | 2027 dates | Source · retrieved |
|---|---|---|---|---|
Weekend and holiday due datesSource text“If the last day for filing a return falls on a Saturday, Sunday, or legal holiday, the return is on time if you file it on the next business day.”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toAn Idaho business income tax return due on a Saturday, Sunday or legal holiday is on time if filed the next business day. | Due ruleNo date: see the source text | 2027 dates— | Source · retrievedtax.idaho.gov/taxes/income-tax/business-income/filing/ (official source, opens in a new tab)retrieved |
Weekend and holiday due datesSource text“If the due date falls on a weekend or state holiday, the form is due on the next business day.”verbatim · tax.idaho.gov · retrieved 2026-09-23 | Applies toAn Idaho withholding form due on a weekend or state holiday is due the next business day. | Due ruleNo date: see the source text | 2027 dates— | Source · retrievedtax.idaho.gov/taxes/income-tax/withholding/withholding-due-dates/ (official source, opens in a new tab)retrieved |
Dates are computed from the linked pages as they read on each retrieval date. Agencies change their pages, and the IRS postpones deadlines after disasters; confirm with the source before filing.
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