Selling a business in Idaho: what the state takes (2026)
Idaho’s top individual income tax rate is 5.3%. Here is what an owner selling company stock pays, with 2026 rules from official sources and worked examples at $10 million, $25 million and $50 million.
- 5.3%
- Top Idaho income tax rate (2026)
- $1,325,000
- State tax on a $25M long-term gain
- 29.1%
- Combined federal and state rate on $25M
- 20 of 51
- Rank by total tax on $25M (1 = highest)
How Idaho taxes a business sale
- Income tax
- Top rate 5.3%: 5.3% on taxable income over $2,500 statutory threshold, indexed for inflation (Tax Foundation lists $4,811).
- Long-term capital gains
- Gain on corporate stock is taxed as ordinary income at the flat 5.3% rate. Idaho's 60% capital gains deduction does not cover corporate stock.
- Relief that applies only in some sales
- Idaho Code 63-3022H gives a 60% deduction for gain on Idaho-situs qualified property: real property held 12 months, tangible personal property used in Idaho for 12 months by a revenue-producing enterprise (manufacturing, processing, wholesale distribution, etc.), certain livestock and timber, and partnership interests only to the extent the gain comes from qualified real property. It can reach part of an S corp or partnership asset sale (flow-through gain on real estate or qualifying equipment), but not goodwill, other intangibles or a stock sale.
- Entity-level taxes
- S corporations generally pass income through; Idaho has an elective pass-through entity tax.
- Local taxes
- No local income taxes.
Three worked examples
| Long-term gain | $10,000,000 | $25,000,000 | $50,000,000 |
|---|---|---|---|
| Federal capital gains tax (20%) | $2,000,000 | $5,000,000 | $10,000,000 |
| Net investment income tax (3.8%) | $380,000 | $950,000 | $1,900,000 |
| Idaho tax | $530,000 | $1,325,000 | $2,650,000 |
| Total tax | $2,910,000 | $7,275,000 | $14,550,000 |
| Effective combined rate | 29.10% | 29.10% | 29.10% |
| Net proceeds after tax | $7,090,000 | $17,725,000 | $35,450,000 |
| Extra tax versus Texas | $530,000 | $1,325,000 | $2,650,000 |
Seller’s tax calculator
Estimate federal and state tax on a stock sale and what is left before fees and debt.
- Long-term capital gain
- $25,000,000
- Federal capital gains tax (20%)
- $5,000,000
- Net investment income tax (3.8%)
- $950,000
- Idaho tax
- $1,325,000
- Taxable gain at 5.3%
- $1,325,000
- Total tax
- $7,275,000
- Effective rate on the gain
- 29.10%
- Net proceeds after tax
- $17,725,000
Illustration, not tax advice. Assumes a resident individual, the whole gain long-term, top marginal rates, no state credits, installment terms, QSBS exclusion or other planning, and no local taxes. Net proceeds are before transaction fees, debt repayment, escrows and earn-outs. Rates are for tax year 2026 where published; see the methodology.
Compare with other states
Neighboring states
Common comparisons
- California37.1% combined, $15.72M net
- New York34.1% combined, $16.48M net
- Texas23.8% combined, $19.05M net
- Florida23.8% combined, $19.05M net
- Tennessee23.8% combined, $19.05M net
Methodology and sources
Idaho figures are for tax year 2026. Idaho Code 63-3024 (last amended 2025, ch. 13 / HB 40) sets a flat 5.3% from 2025 onward; the 2026 session (HB 559, federal conformity) did not change the rate. The $2,500 statutory threshold is indexed; the 2026 indexed figure was not published in a retrieved source. The examples assume a resident individual selling privately held stock for a long-term gain equal to the sale price (zero basis), with every dollar taxed at the top marginal rates, the federal 20% capital gains rate and the 3.8% net investment income tax, and no planning, credits or local taxes. Full assumptions are in the report methodology.
All 50 states and DC with source URLs.
- 1Idaho Code 63-3024 (individual rate 5.3%)
- 2Idaho Code 63-3022H (capital gains deduction, qualified property)
- 3Idaho State Tax Commission, individual income tax online guide (2025 rate 5.3%)
- 4Tax Foundation, State Individual Income Tax Rates and Brackets, 2026. Secondary source
Data last updated October 26, 2026.
Cite this research
You may quote and republish figures from this page with attribution and a link to the source.
Citation
Laurent Capital Research, “The Seller’s Tax Map: What Selling a Business Costs in Every State (2026): Idaho,” 2026, https://laurent.capital/research/seller-tax-map/idahoLink (HTML)
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