Quarterly Taxes
Last reviewed 2026-05-11 by Asad Ali, Founder & CEO
Estimated tax payments due four times per year for self-employed individuals.
Quarterly taxes are estimated tax payments submitted to the IRS (and most state tax authorities) on roughly April 15, June 15, September 15, and January 15 of the following year. They cover the federal income tax and self-employment tax that is not withheld by an employer, so they are the primary tool for sole proprietors, single-member LLC owners, partners, S-corp shareholders, gig workers, and landlords. Quarterly periods are not equal — Q1 covers 3 months (Jan–Mar), Q2 covers 2 months (Apr–May), Q3 covers 3 months (Jun–Aug), and Q4 covers 4 months (Sep–Dec) — but the IRS expects four roughly equal payments unless you use the annualized income installment method (Form 2210 Schedule AI) to match payments to actual income flow. Underpayment penalties apply if you owe more than $1,000 at filing without meeting one of two safe harbors: (a) 90% of current-year tax, or (b) 100% of last year's tax (110% if last year's AGI exceeded $150,000). Make payments via IRS Direct Pay, EFTPS, IRS2Go, debit/credit card, or Form 1040-ES voucher. See IRS Publication 505.
Formula
Quarterly Payment = (Projected Annual Income Tax + Self-Employment Tax − Withholding) ÷ 4. Safe Harbor (no penalty) = lesser of 90% current-year tax or 100% prior-year tax (110% if prior AGI > $150,000).Example
A consultant earns roughly $40,000 per quarter ($160,000 annual). Each quarter she sets aside 30% ($12,000) for federal taxes and submits via IRS Direct Pay by the deadline. Total federal estimated payments = $48,000 for the year. At filing she compares actual tax liability to estimated payments: if actual tax is $46,000, she receives a $2,000 refund; if actual is $52,000, she owes $4,000 plus potentially an underpayment penalty unless she met safe harbor (e.g., last year's total tax was $43,000, so she paid $48,000 which exceeds 110% of $43,000 = $47,300, qualifying for safe harbor — no penalty).
Why It Matters for Your Business
Missing quarterly payments triggers penalties that accumulate daily at the federal short-term rate plus 3%, and a surprise April tax bill of $20,000+ is a leading cause of cash flow crisis for new freelancers.
Practical Tips
- •Calendar all four due dates the moment you read this — April 15, June 15, September 15, January 15 — and set up automated transfers from operating to a tax-savings account on the 1st of each month
- •Use the safe harbor based on prior-year tax — it removes guesswork and locks in zero penalty even in a high-income year
- •For variable income (consultants, contractors), apply the annualized income installment method on Form 2210 Schedule AI rather than four equal payments — this matches your obligation to your actual earnings
- •Always pay state estimated taxes the same day as federal — most states have parallel deadlines and parallel underpayment penalties
Common Questions About Quarterly Taxes
How is quarterly taxes calculated?
The formula is: Quarterly Payment = (Projected Annual Income Tax + Self-Employment Tax − Withholding) ÷ 4. Safe Harbor (no penalty) = lesser of 90% current-year tax or 100% prior-year tax (110% if prior AGI > $150,000).. See the worked example below for a step-by-step calculation using realistic numbers.
What is an example of quarterly taxes?
A consultant earns roughly $40,000 per quarter ($160,000 annual). Each quarter she sets aside 30% ($12,000) for federal taxes and submits via IRS Direct Pay by the deadline. Total federal estimated payments = $48,000 for the year. At filing she compares actual tax liability to estimated payments: if actual tax is $46,000, she receives a $2,000 refund; if actual is $52,000, she owes $4,000 plus potentially an underpayment penalty unless she met safe harbor (e.g., last year's total tax was $43,000, so she paid $48,000 which exceeds 110% of $43,000 = $47,300, qualifying for safe harbor — no penalty).
Why does quarterly taxes matter for my business?
Missing quarterly payments triggers penalties that accumulate daily at the federal short-term rate plus 3%, and a surprise April tax bill of $20,000+ is a leading cause of cash flow crisis for new freelancers.
How does FiscalInsights help with quarterly taxes?
FiscalInsights tracks quarterly taxes automatically as part of its AI bookkeeping workflow. Connect your bank accounts and the platform handles categorization, reconciliation, and reporting without manual entry.
Related Terms
More Taxes Terms
Tax Deduction
An expense that reduces taxable income.
Estimated Taxes
Quarterly tax payments made by self-employed individuals and businesses.
Form 1099
IRS forms reporting various types of income other than wages.
Form W-2
Annual statement from employers showing employee wages and taxes withheld.
Payroll Tax
Taxes withheld from employee wages for Social Security and Medicare, plus employer-side employment taxes.
Related Taxes Guides
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