Glossary
What is Quarterly Estimated Taxes?
Definition
Quarterly estimated taxes are four advance tax payments US freelancers and self-employed individuals send the IRS across the year in place of the withholding an employer would otherwise handle. They cover both federal income tax and self-employment tax on the year's earnings.
The four deadlines are April 15, June 15, September 15, and January 15 (of the following year). State tax authorities usually mirror these dates but operate separately.
Why it matters
- Missing a payment triggers the IRS underpayment penalty — effectively ~8% annualized interest calculated from the missed due date to when you eventually pay.
- The IRS assumes taxes are paid throughout the year. A freelancer who pays nothing until April 15 and then writes one big check still owes the penalty, even if the final amount was correct.
- Two safe-harbor rules eliminate the penalty entirely: pay 100% of last year's total tax (110% if AGI was over $150k), or pay 90% of this year's actual tax. Either one, no penalty.
Best practices for Quarterly Estimated Taxes
Default to the 100%/110% safe harbor
Take last year's 1040 line 24 (total tax), divide by 4, send that four times. No forecasting required. Works even if income doubles or halves this year.
Pay via IRS Direct Pay (no fees)
directpay.irs.gov accepts bank debits with zero fees. Takes 2 minutes per quarter. EFTPS is the heavier alternative that lets you schedule all four at once.
Keep a separate tax-savings account
Transfer 30% of every client payment to a dedicated savings account. When the quarterly deadline arrives, the money is already waiting — no scrambling.
Send state payments the same day as federal
Most states with income tax mirror the federal deadlines and have their own online payment portals. Doing both in one sitting prevents state-only misses.
FAQ
Do I need to pay quarterly estimates if I also have a W-2 job?
Only if your freelance tax liability exceeds what your W-2 withholding already covers. You can have extra withheld from the W-2 to avoid quarterly estimates entirely — this is often simpler for freelancers with a small side stream.
What happens if I underpay one quarter but catch up the next?
The underpayment penalty is calculated quarter-by-quarter, so catching up doesn't erase a missed Q1. The penalty for the missed period still applies, but it stops accruing once you're caught up.
Can I pay more than the safe harbor requires?
Yes, and many freelancers do if they expect this year's income to be higher than last year's. Overpaying is refunded when you file in April. The only downside is the opportunity cost of the cash sitting with the IRS vs in a savings account.
Ready to automate this out of your life?
Hustlay calculates your quarterly estimate from your actual year-to-date profit, sends calendar reminders before each deadline, and generates the exact amount to pay.