As a 1099 real estate agent, nobody is withholding taxes from your commission checks. The IRS and Arizona both expect you to pay as you earn throughout the year rather than waiting until April. That means quarterly estimated tax payments at the federal and state level.

On the federal side, you file Form 1040-ES each quarter if you expect to owe $1,000 or more for the year. The quarterly due dates are April 15, June 15, September 15, and January 15 of the following year. Miss a payment or underpay, and the IRS charges an underpayment penalty that functions like interest on what you should have sent in.

The part that surprises many real estate agents is self-employment tax. Since you’re not a W-2 employee, you pay both the employer and employee portions of Social Security and Medicare. That comes to 15.3% on your net self-employment income (12.4% for Social Security up to the wage base limit, plus 2.9% for Medicare). This is on top of your federal income tax. The good news is you can deduct half of the self-employment tax when calculating your adjusted gross income, but the bill still hits harder than most agents expect in their first year on 1099.

For Arizona, you file Form 140ES on the same quarterly schedule. Arizona has a flat state income tax rate of 2.5%, which simplifies the calculation compared to states with graduated brackets.

The practical rule of thumb is to set aside 25 to 30 percent of your net commission income for taxes. Net means after you subtract business expenses like MLS fees, marketing costs, mileage, continuing education, and brokerage splits that come out of your check. If you have a strong year and land in a higher federal bracket, 30% is the safer number. If your deductions are significant, 25% might be enough.

The easiest way to stay on track is to move that percentage into a separate savings account every time a commission deposits. Agents who spend first and try to come up with tax money later often end up short at payment time. Quarterly payments based on last year’s income (called the safe harbor method) can also protect you from underpayment penalties even if this year’s income is higher.

Keeping clean books throughout the year makes estimated tax calculations much easier. When your income and expenses are tracked monthly, you can see where you stand and adjust your quarterly payments rather than guessing. That’s true whether you handle construction job costing in Phoenix or commission-based real estate income. Good financial data removes the guesswork from tax planning and helps you avoid surprises in April.