Idaho Quarterly Tax Calculator 2026
Rates reviewed · Idaho State Tax Commission
Idaho has a flat 5.8% income tax rate. Quarterly estimated payments required if you expect to owe $500 or more.
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Tax Information Notice
This content is for informational and educational purposes only. It does not constitute tax, legal, or financial advice. Tax laws change frequently. Always consult a qualified CPA or Enrolled Agent for your specific situation.
Idaho quarterly tax questions
How much is the quarterly tax for freelancers in Idaho?
Freelancers in Idaho pay federal self-employment tax (15.3% of net self-employment income), federal income tax at their bracket, and Idaho income tax of 5.8% flat. This calculator applies 5.8% as a representative Idaho rate for freelancer-level income; the top marginal rate is 5.8% flat.
When are quarterly estimated taxes due in Idaho for 2026?
Idaho follows the federal estimated tax schedule for 2026 — Q1: April 15, 2026, Q2: June 16, 2026, Q3: September 15, 2026, Q4: January 15, 2027. The Q3 payment is due September 15, 2026.
Do I have to make Idaho estimated tax payments?
Idaho requires estimated payments once you expect to owe $500 or more in state income tax for the year. The state form is Form 51. Payments can be made online through Taxpayer Access Point. Filing and paying federal estimated tax does not cover the state amount — they are separate payments.
Where do I pay Idaho estimated taxes online?
Idaho accepts online estimated tax payments through Taxpayer Access Point, run by the Idaho State Tax Commission. Federal payments go through IRS Direct Pay or EFTPS separately.
What happens if I underpay estimated taxes in Idaho?
The IRS charges an underpayment penalty based on the amount underpaid and the number of days late. Paying at least 90% of this year's tax or 100% of last year's (110% if your AGI exceeded $150,000) meets the federal safe harbour. Idaho applies its own interest and penalty on late or short state payments.
State payments are administered by the Idaho State Tax Commission via Taxpayer Access Point.
Tax Information Notice
This content is for informational and educational purposes only. It does not constitute tax, legal, or financial advice. Tax laws change frequently. Always consult a qualified CPA or Enrolled Agent for your specific situation.