Quarterly Estimated Tax Payments: Who Needs to Pay and How to Calculate Them

The U.S. tax system is pay-as-you-go. If you're an employee, your employer handles this automatically through withholding. But if you're self-employed, a freelancer, or have significant income from investments or a side business, you're generally required to pay estimated taxes four times a year — and skipping them can mean penalties even if you pay everything owed by the April deadline.

Who Needs to Pay

Generally, you need to make estimated payments if you expect to owe at least $1,000 in tax for the year after subtracting withholding and refundable credits. This commonly applies to self-employed people, freelancers, landlords, and anyone with substantial investment or business income.

The Quarterly Due Dates (Not Actually Quarters)

• Q1 (Jan 1 – Mar 31): due April 15
• Q2 (Apr 1 – May 31): due June 15
• Q3 (Jun 1 – Aug 31): due September 15
• Q4 (Sep 1 – Dec 31): due January 15 of the following year

How to Calculate Your Payment

The simplest 'safe harbor' approach: pay 100% of last year's total tax liability (110% if your prior-year adjusted gross income was over $150,000), divided into four equal payments. As long as you meet this threshold, you generally avoid an underpayment penalty even if you end up owing more when you file.

What Happens If You Skip a Payment

The IRS charges an underpayment penalty calculated like interest on the shortfall for each period you underpaid, even if your final return shows a refund is coming for the year overall. Paying late is better than not paying, but paying on time avoids the penalty entirely.