Written by Lorrie Contreras | Last updated: February 2026
If you are self-employed, a freelancer, or an independent contractor in Arizona, you are generally required to make quarterly estimated tax payments to both the IRS and the Arizona Department of Revenue.
Who Needs to Pay Estimated Taxes?
You generally need to make estimated tax payments if:
- You expect to owe $1,000 or more in federal tax after subtracting withholding and credits
- You expect to owe $1,000 or more in Arizona state tax
- You are self-employed, a freelancer, or receive significant non-wage income
Federal Estimated Tax Due Dates
- Q1: April 15
- Q2: June 15
- Q3: September 15
- Q4: January 15 (of the following year)
How to Calculate Your Estimated Taxes
The IRS provides Form 1040-ES with a worksheet. A general approach:
- Estimate your total income for the year
- Subtract expected deductions
- Apply the self-employment tax rate (15.3% for Social Security and Medicare)
- Apply income tax rates to your taxable income
- Divide by 4 for quarterly payments
Arizona Estimated Taxes
Arizona requires estimated payments using Form 140ES. The state uses a flat income tax rate. Check the Arizona Department of Revenue website for current rates and forms.
Penalties for Not Paying
Both the IRS and Arizona can charge penalties for underpayment of estimated taxes. The penalty is essentially interest on the underpaid amount for the period it was underpaid.
How We Help
We calculate your estimated tax obligations and provide payment vouchers as part of our self-employed tax preparation service.
Questions? Contact us or call (480) 330-4960.