Quarterly Taxes Demystified. Never Miss a Payment Again.
Estimated tax payments don't have to be stressful. Learn exactly when to pay, how much, and how to avoid penalties.
A guide by Taxstra Tax & Accounting — CPA-led tax strategy for business owners
What Are Estimated Taxes?
The U.S. tax system is "pay-as-you-go." W-2 employees have taxes withheld from every paycheck. Self-employed individuals and business owners must pay their own way — quarterly.
The $1,000 Rule
If you expect to owe $1,000 or more in federal taxes after subtracting withholding and refundable credits, the IRS requires you to make quarterly estimated payments.
Who Must Pay
Sole proprietors, single-member LLCs, S-Corp owners (on K-1 income), partners, freelancers, and anyone with significant non-wage income (investments, rental income, etc.).
This guide covers the small-business angle. If you freelance or run an online business, see our companion guide to quarterly estimated taxes for the self-employed.
2026 Quarterly Tax Due Dates
Mark these dates. Missing them triggers automatic underpayment penalties.
| Quarter | Income Period | Payment Due |
|---|---|---|
| Q1 | Jan 1 – Mar 31 | April 15, 2026 |
| Q2 | Apr 1 – May 31 | June 15, 2026 |
| Q3 | Jun 1 – Aug 31 | September 15, 2026 |
| Q4 | Sep 1 – Dec 31 | January 15, 2027 |
* If a due date falls on a weekend or holiday, the deadline moves to the next business day. Use Form 1040-ES or pay online at IRS.gov/payments.
How to Calculate Your Payments
Two methods to calculate how much to pay each quarter — and one of them guarantees no penalties.
Safe Harbor Method
Pay 100% of last year's tax liability divided into 4 equal payments. If your AGI exceeded $150K, pay 110% of last year's liability.
Guarantee: If you meet safe harbor, you'll owe zero penalties — even if you owe a large balance when you file.
Current Year Estimate
Estimate your current year's income, deductions, and credits, then pay 90% of the projected tax in quarterly installments. More precise but requires accurate forecasting.
Best for: Businesses with variable or rapidly growing income where last year's numbers are no longer relevant.
The S-Corp Difference
If you run an S-Corp, your quarterly tax situation is different — and often simpler.
Payroll Withholding Covers Part of It
When you run payroll as an S-Corp owner, federal income tax, Social Security, and Medicare are withheld from each paycheck — just like a W-2 employee. This withholding counts toward your annual tax liability.
You May Owe Less in Estimates
Because payroll withholding covers your salary income, you only need to make estimated payments on the distribution (K-1) portion of your income that isn't covered by withholding. This often dramatically reduces your quarterly payment amounts.
Pro Tip: Increase W-2 Withholding
Some S-Corp owners increase their W-2 withholding to cover their entire projected tax liability, eliminating the need for separate estimated payments altogether. W-2 withholding is treated as paid evenly throughout the year — even if you increase it in December.
Underpayment Penalties
How they work — and how to make sure you never owe one.
How Penalties Work
The IRS calculates the penalty on Form 2210. They take each quarter's required payment, compare it to what you actually paid, and charge interest on the shortfall from the due date until you pay.
The current underpayment rate is the federal short-term rate plus 3 percentage points, updated quarterly. Even a small shortfall can result in hundreds in penalties over the year.
How to Avoid Them
- Pay 100% of prior year tax (110% if AGI > $150K)
- Or pay 90% of current year tax
- Make payments on time each quarter
- Use the annualized income method if income varies
- Increase W-2 withholding (if S-Corp or W-2 employed)
- Set up automatic IRS payments via EFTPS
Already received a penalty notice — or worried you will? Our estimated tax penalty guide walks through how the penalty is calculated and your options for reducing or removing it.
Let Us Handle Your Quarterly Taxes
With our monthly accounting service, we calculate your estimated payments, send you reminders before each deadline, and ensure you never overpay or underpay.
We Calculate
Quarterly estimates based on real-time financials — not last year's guess.
We Remind
Payment reminders 2 weeks before every due date so you're never late.
We Protect
Safe harbor compliance guaranteed. Zero underpayment penalties.
FAQs
Your questions about estimated tax payments, answered
Never Miss a Payment Again.
Book a free strategy call. We'll review your estimated tax situation and make sure you're on track for the year.
Find Out What You're Overpaying in Taxes
Book a free 30-minute call to walk through your situation. We'll tell you exactly how our CPA-led team can help — and whether we're the right fit.