How to File Quarterly Estimated Taxes as a Solo Attorney Practice
Learn the step-by-step process for filing quarterly estimated taxes as a solo attorney, including deadlines, calculations, and payment methods.
As a solo attorney, you’re responsible for paying taxes on your income throughout the year, not just at tax time. The IRS requires quarterly estimated tax payments if you expect to owe at least $1,000 in tax after withholdings and credits. This guide walks you through the process, from calculating your payments to submitting them on time.
Who Must Pay Quarterly Estimated Taxes
You must make quarterly estimated tax payments if you’re a sole proprietor, partner, or S-corp shareholder and you expect to owe at least $1,000 in tax for the year. For most solo attorneys, this applies because you don’t have an employer withholding taxes from your paycheck. Even if you have a day job with withholding, you may still need to make estimated payments if your total tax liability exceeds that threshold.
How to Calculate Your Estimated Tax
To calculate your estimated tax, you need to project your adjusted gross income (AGI), taxable income, taxes, deductions, and credits for the year. Here’s a simplified method:
- Estimate your annual income: Add up all income sources, including legal fees, retainers, and any other business income.
- Subtract business expenses: Deduct ordinary and necessary expenses like office rent, software subscriptions, continuing education, and marketing.
- Calculate your adjusted gross income: Subtract adjustments like retirement plan contributions (e.g., SEP IRA, solo 401(k)) and health insurance premiums.
- Determine your taxable income: Subtract the standard deduction ($14,600 for single filers in 2024, but adjust for 2026) or itemized deductions.
- Apply tax rates: Use the 2026 tax brackets to estimate your tax liability.
- Subtract credits and withholdings: Include any tax credits you qualify for and any federal income tax withheld from other jobs.
- Divide by 4: If your total estimated tax is over $1,000, divide it by 4 to get your quarterly payment amount.
For accuracy, use IRS Form 1040-ES and its worksheet. Many accounting software programs (QuickBooks, FreshBooks) can also calculate this for you.
Quarterly Due Dates for 2026
The IRS sets four payment deadlines each year. For 2026, the due dates are:
| Quarter | Payment Period | Due Date |
|---|---|---|
| 1st | Jan 1 - Mar 31 | April 15, 2026 |
| 2nd | Apr 1 - May 31 | June 15, 2026 |
| 3rd | Jun 1 - Aug 31 | September 15, 2026 |
| 4th | Sep 1 - Dec 31 | January 15, 2027 |
If a due date falls on a weekend or holiday, the payment is due the next business day. Mark these dates on your calendar and set reminders.
How to Pay Your Quarterly Estimated Taxes
You have several payment options, each with its own pros and cons:
- Electronic Federal Tax Payment System (EFTPS): Free, secure, and allows you to schedule payments in advance. You must enroll in advance, which takes about a week.
- IRS Direct Pay: Free, no enrollment required, but you can’t schedule future payments. Good for one-time payments.
- Credit or debit card: Convenient, but the IRS charges a processing fee (around 1.85% to 2.0% of the payment).
- Check or money order: Mail with Form 1040-ES payment voucher. Slower and less secure.
For most solo attorneys, EFTPS or IRS Direct Pay are the best choices. They’re free and provide instant confirmation.
What If You Miss a Payment?
If you miss a quarterly deadline, you’ll likely face an underpayment penalty. The IRS calculates this penalty based on the amount you owe and how long it’s overdue. The current rate is about 8% per year, compounded daily. To avoid this, make your payments on time. If you realize you underpaid, increase your next payment to catch up, but the penalty may still apply for the late period.
Safe Harbor Rules
To avoid penalties, you can use the safe harbor rule: pay at least 100% of last year’s tax liability (or 110% if your adjusted gross income was over $150,000). This is a simple way to ensure you’re paying enough, even if your income fluctuates. For example, if your 2025 tax bill was $20,000, you’d pay $5,000 per quarter in 2026, regardless of your actual income.
State Quarterly Taxes
Many states also require quarterly estimated tax payments for state income tax. Check with your state’s tax agency for deadlines and payment methods. Some states align with federal deadlines, but others differ. Don’t forget this obligation, as underpayment penalties apply at the state level too.
Common Mistakes to Avoid
- Forgetting to pay: Set calendar reminders for each deadline.
- Underestimating income: Be conservative and adjust payments if your income changes.
- Mixing business and personal expenses: Keep separate accounts for clean records.
- Ignoring state taxes: Research your state’s requirements.
- Not adjusting for retirement contributions: These reduce your taxable income, so factor them in.
FAQ
Q: Can I pay quarterly taxes with a credit card? A: Yes, but the IRS charges a processing fee of about 1.85% to 2.0%. For a $5,000 payment, that’s $92 to $100. Consider EFTPS or Direct Pay to avoid fees.
Q: What if my income is irregular? A: Use the annualized income installment method (Form 2210) to calculate payments based on your actual income each quarter. This can reduce penalties if you earn more later in the year.
Q: Do I need to file a separate return for estimated taxes? A: No, you report estimated payments on your annual tax return (Form 1040). The quarterly payments are just prepayments of your total tax.
Q: Can I pay all at once instead of quarterly? A: You can pay the full amount early, but you’ll still need to meet the quarterly deadlines to avoid penalties. Paying early doesn’t exempt you from the schedule.
The Bottom Line
Filing quarterly estimated taxes is a non-negotiable part of running a solo practice. Calculate your payments using Form 1040-ES, pay via EFTPS or Direct Pay, and mark the four deadlines in your calendar. Use the safe harbor rule to simplify, and don’t forget state taxes. By staying on top of these payments, you’ll avoid penalties and keep your finances healthy. If you’re unsure, consult a CPA who works with attorneys to ensure you’re compliant.