Quarterly estimated taxes are payments self-employed people and many business owners make to the IRS during the year, because no employer is withholding tax from their pay. They cover both income tax and self-employment tax. They catch owners off guard because nothing reminds you they're due, and a new owner's first big tax bill often arrives at the same time as the first estimated payment.
This guide is for sole proprietors, freelancers, partners and single-member LLC owners in the U.S., especially in their first few years. You'll learn how the payment schedule works, see a worked example of the "double payment" that surprises new owners, and set up a simple system so the money is always there. Tax rules change and depend on your situation, so use this as background and confirm your numbers with a CPA or tax professional.
Why estimated taxes exist, and who has to pay them
The federal tax system is pay-as-you-go. Employees pay through withholding from each paycheck. When you work for yourself, no one withholds anything, so you're expected to send payments on your own as you earn income.
You generally need to make estimated payments if you expect to owe more than a set minimum amount of federal tax for the year after subtracting any withholding and credits. The IRS publishes that threshold, and it's worth checking each year. Many states have their own estimated tax requirements too.
Two taxes are usually involved:
- Self-employment tax. This is Social Security and Medicare for people who work for themselves. It totals 15.3%: 12.4% for Social Security, which applies only up to an annual wage cap, plus 2.9% for Medicare. It's calculated on 92.35% of your net self-employment earnings. Our explainer on what self-employment tax is covers the details.
- Income tax. Federal and often state income tax on your business profit, along with any other income you have.
If you own an S corporation and pay yourself a salary through payroll, withholding on that salary may cover some or all of what you owe. Profit distributions above salary may still require estimates. That's a situation to plan with your CPA.
The four estimated tax payment periods
Here's the part that surprises people: the "quarters" aren't equal, and the last payment falls in the following year.
| Income earned | Payment generally due | Months covered |
|---|---|---|
| January 1 – March 31 | April 15 | 3 |
| April 1 – May 31 | June 15 | 2 |
| June 1 – August 31 | September 15 | 3 |
| September 1 – December 31 | January 15 of the next year | 4 |
When a due date lands on a weekend or holiday, it usually moves to the next business day. Confirm the exact dates on the IRS website each year and put them in your calendar with a two-week reminder.
Paying too little or too late can trigger an underpayment penalty, which works much like interest calculated on each late or short payment. The IRS offers "safe harbor" rules: if you pay at least a set percentage of this year's tax, or an amount based on last year's total tax (a higher percentage applies above a certain income), you generally avoid the penalty even if you owe more when you file. Ask your CPA which safe harbor fits you.
Worked example: a mobile dog groomer's first two years
Suppose a hypothetical groomer leaves a salaried job at a pet store and starts a mobile grooming business as a sole proprietor. In her first year of self-employment, she earns a net profit of $72,000 and makes no estimated payments. She's never had to before.
Step 1: Self-employment tax
- Taxable base: $72,000 × 0.9235 = $66,492
- Self-employment tax: $66,492 × 0.153 = $10,173 (rounded)
Her earnings are well below the Social Security wage cap, so the full 15.3% applies.
Step 2: Income tax
Income tax depends on filing status, deductions, other household income and the current year's brackets, so the groomer asks her CPA for an estimate. For this illustration, assume the CPA estimates $7,000 of federal income tax.
Step 3: The total
Total estimated federal tax: $10,173 + $7,000 = $17,173. That's $17,173 ÷ $72,000 = about 24% of her profit.
Step 4: The April surprise
Next April, two things come due at once:
- The balance for her first year: $17,173 (plus a possible underpayment penalty, depending on the safe harbor rules and her prior-year withholding).
- Her first estimated payment for year two. If she expects similar profit, that's $17,173 ÷ 4 = about $4,293.
Total due in one month: $17,173 + $4,293 = $21,466. That's the moment many new owners discover estimated taxes. It's not a mistake in the system; it's the system catching up.
Step 5: The fix
If she had moved 24% of each month's profit into a separate tax savings account from day one, the $17,173 would have been sitting there. Going forward, a $6,000 profit month means $6,000 × 0.24 = $1,440 goes to the tax account, and each quarterly payment comes out of that account rather than her operating cash.
To estimate your own self-employment tax, try our self-employment tax calculator, then add your CPA's income tax estimate.
How to set up a tax set-aside system that works
- Open a separate savings account used only for taxes. If it's in the same account as operating cash, it will get spent. Keeping business and personal money apart in general helps too; see why you need a separate business bank account.
- Get a set-aside percentage from your CPA. They'll factor in your income tax bracket, state taxes, deductions and household income. Until you have it, many owners use a conservative placeholder and adjust later.
- Transfer on a fixed schedule. Weekly or each time you pay yourself. Base the transfer on profit, not revenue, or on revenue at a lower percentage if profit is hard to calculate weekly.
- Calendar the four due dates with reminders two weeks ahead.
- Recalculate midyear. If profit is running well above or below your estimate, adjust the remaining payments with your CPA. Seasonal businesses can ask about the annualized income method, which matches payments to when income was actually earned.
- Keep the surplus. If the account has more than you owe after filing, treat it as the start of next year's set-aside or a cash reserve, not a windfall.
Common estimated tax mistakes
- Forgetting self-employment tax. Owners often plan for income tax alone. At 15.3% on most of your profit, self-employment tax is frequently the larger of the two for modest earners.
- Setting aside a percentage of revenue that's too low. If your margins are thin, a percentage of revenue can badly underestimate tax on profit, or overestimate it if you have heavy expenses. Base it on profit when you can.
- Treating the tax account as an emergency fund. Borrowing from it "just this once" is how owners end up owing thousands in April. Keep a separate cash reserve for emergencies.
- Ignoring state estimates. Many states have their own schedule and rules. Ask your CPA whether yours applies.
- Paying four equal amounts on seasonal income. If most of your profit comes in the fall, equal payments may be more than you can afford early and still leave penalties. Discuss the annualized method.
- Skipping payments after a profitable deduction-heavy year. Big equipment purchases may lower income tax, but they don't always lower self-employment tax in the same way. Check before assuming you owe nothing.
Where AI can help
An AI assistant can turn your year-to-date profit and your CPA's set-aside percentage into a running tracker: how much should be in the tax account by now, what each remaining payment should be, and whether you're ahead or behind. It can also draft a reminder schedule or summarize a long IRS instruction page into plain questions to bring to your CPA.
Don't rely on a general AI tool for current tax rates, thresholds or due dates. These change, and tools can repeat outdated figures confidently. Verify anything you'll act on against official IRS sources or with your tax professional.
For ways to lower the bill legitimately, read about small business tax deductions owners commonly miss.
Frequently asked questions
What happens if I miss a quarterly estimated payment?
You may owe an underpayment penalty, which is calculated like interest on the amount that was short, for the time it was late. Make the payment as soon as you can to limit it, and ask your CPA whether a safe harbor or the annualized method reduces or eliminates the penalty.
Do I have to pay estimated taxes in my first year of business?
It depends on how much you expect to owe and on your prior-year tax situation. Some owners are covered by a safe harbor in year one, but even then the full tax is due when you file. Setting money aside from the start avoids the April surprise either way.
How much should I set aside for taxes as a self-employed person?
It depends on your income, deductions, state and household situation. Self-employment tax alone is about 14% of net profit (15.3% × 92.35%), before income tax. Ask your CPA for a total percentage tailored to you.
Can I pay estimated taxes monthly instead of quarterly?
Generally yes. You can pay more often than the four due dates, and many owners find smaller, frequent payments easier to manage. What matters is that enough has been paid by each due date.
Key takeaways
- Estimated taxes replace the withholding an employer would do, covering both income tax and self-employment tax.
- The four periods are unequal, and the fourth payment is due in January of the following year.
- New owners often face last year's full balance and this year's first estimate in the same April.
- Move a CPA-recommended percentage of profit into a separate tax account every week or month.
- Recheck midyear and ask about safe harbors and the annualized method if your income is uneven.
Comments
Post a Comment