Quarterly Taxes: What They Are, Who Needs to File, and How to Get Them Right

If you’re self-employed, run a small business, or earn income outside of a traditional paycheck, quarterly estimated taxes are likely something you need to pay attention to. Skipping them can result in penalties, interest, or a surprise bill come tax season.

Here’s what you need to know about quarterly tax payments—what they are, who needs to pay them, when they’re due, and how to calculate them to avoid penalties and interest.

What Are Quarterly Taxes, and Who Needs to File Them?

Quarterly estimated taxes are advance payments made to the IRS to cover income that isn’t subject to withholding. This includes:

  • Self-employment or freelance income

  • Side jobs and gig work

  • Rental property income

  • Investment or dividend earnings

  • Business profits from partnerships or S corporations

You’re generally required to make estimated payments if you expect to owe $1,000 or more in taxes after subtracting withholding and credits. This applies whether you’re an individual with a side hustle or a full-time business owner.

When Are Quarterly Taxes Due?

Estimated tax payments are due four times each year on the following schedule:

  • 1st Quarter Payment – April 15, 2025

  • 2nd Quarter Payment – June 17, 2025 (adjusted for weekend)

  • 3rd Quarter Payment – September 15, 2025

  • 4th Quarter Payment – January 15, 2026

If the due date falls on a weekend or holiday, the deadline shifts to the next business day.

How to Estimate What You Owe and the Safe Harbor Rule

Method 1: Estimate Based on This Year’s Income

Start by projecting your income and expenses for the year. Then calculate your expected tax liability, including:

  • Federal income tax

  • Self-employment tax (typically 15.3%)

  • Any applicable state tax

Divide your estimated tax by four to get your quarterly payment amount.

Example:

If you expect to owe $24,000 in total tax for the year, each quarterly payment would be $6,000.

Method 2: Use the Safe Harbor Rule

If your income varies or you’re unsure how much you’ll make, the IRS allows a safe harbor to help avoid penalties:

  • Pay 100% of your prior year’s total tax (or 110% if your adjusted gross income was over $150,000)

  • Split that evenly across the four quarters

As long as you meet this threshold, you won’t face underpayment penalties—even if your actual tax liability ends up being higher.

What Happens If You Don’t Make Quarterly Payments?

If you don’t make your required estimated tax payments or you underpay, the IRS may charge penalties and interest, even if you pay the full amount by the time you file your return.

The Underpayment Penalty

This isn’t a flat fee. Instead, the IRS calculates it based on:

  • How much you underpaid

  • How long the payment was late

  • The IRS interest rate at the time (typically between 6–8%)

Penalties can add up quickly, especially for self-employed individuals with high net income. For example, if you underpay by $10,000 and the IRS rate is 7%, you could owe hundreds in interest and penalties—on top of your original tax bill.

You can be penalized even if:

  • You pay your full tax balance at the end of the year

  • You file your return on time

  • You simply missed one or two quarterly payments

The IRS assesses the penalty on each missed or short-paid quarter individually, so it’s not always obvious until you file your return.

How to Avoid It

  • Use the safe harbor rule to ensure you’re paying enough

  • Work with a CPA to fine-tune your estimated payments based on current-year income and deductions

  • Stay on top of the due dates to avoid late payments

Work With a CPA to Avoid Overpaying or Getting Penalized

Making estimated payments correctly isn’t just about avoiding IRS penalties. It’s also about keeping more of your money throughout the year.

As a licensed CPA, I help individuals and small business owners:

  • Accurately calculate quarterly tax payments

  • Avoid unnecessary penalties

  • Reduce overpayments by identifying eligible deductions

  • Stay compliant with IRS and state deadlines

Missing a deadline can lead to IRS penalties and interest. If you’re not sure how much to pay or want to avoid overpaying, I can help.

Michael Bottala, CPA

Email: michael@bottalacpa.com

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