1099 Quarterly Taxes in Idaho (2026)
If you're self-employed in Idaho — freelancer, contractor, gig worker, or single-member LLC — you owe quarterly estimated taxes to two agencies: the IRS (federal) and Idaho State Tax Commission (state). Idaho uses a flat 5.30% income tax, which makes estimating your state burden simpler than progressive states. But you still need to send the money on time to avoid underpayment penalties.
Idaho state income tax (2026)
Idaho uses a flat income tax rate of 5.30% on all taxable income above the standard deduction. There are no brackets — every dollar of taxable income is taxed at the same rate.
How to pay Idaho estimated taxes
Federal estimated tax due dates (April 15, June 15, September 15, 2026, and January 15, 2027) apply to your Idaho state estimated payments as well — most states piggyback on the federal schedule. Pay Idaho taxes through the Idaho State Tax Commission's online portal: tax.idaho.gov/i-1067.cfm. You can also mail Form 51 with a check.
Idaho-specific quirk freelancers miss
Idaho went flat in 2023 (initially 5.8%) and stepped down to 5.3% effective Jan 1, 2025 via HB 40. Capital gains from Idaho property are eligible for a 60% deduction — useful for self-employed real estate professionals.
Common deductions for Idaho freelancers
- Idaho allows the same business expenses (home office, mileage, software, etc.) as federal.
- Half of SE tax is deductible federally; check Idaho's rules for state conformity.
- ID conforms to federal QBI deduction.
- SEP-IRA / Solo 401(k) contributions reduce both federal and Idaho taxable income.
- Self-employed health insurance premiums are deductible federally.