If you\'re self-employed or have side income, the IRS expects four payments a year: April 15, June 15, September 15, and January 15. Miss one and the underpayment penalty starts running, even if you pay the others.
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| Quarter | Due date & period covered |
| Q1 | April 15, 2026 — for income earned Jan 1 to Mar 31 |
| Q2 | June 15, 2026 — for income earned Apr 1 to May 31 |
| Q3 | September 15, 2026 — for income earned Jun 1 to Aug 31 |
| Q4 | January 15, 2027 — for income earned Sep 1 to Dec 31 |
Notice the quarters aren't evenly spaced. Q2 covers only two months and Q4 covers four. The dates themselves are fixed — only the period covered changes.
The IRS rule: if you expect to owe more than $1,000 in tax for the year after subtracting your withholding and credits, you need to pay estimated tax. That threshold catches a lot of people who don\'t think of themselves as "self-employed."
1099 income with no withholding. Even part-time side work over $5,000–$10,000 typically triggers the requirement.
Rental income net of expenses. The withholding from your day job rarely covers it.
If you sold investments, real estate, or crypto at a profit during the year. Large dividends or interest also count.
W-2 employees with normal withholding usually don\'t need to file estimates. But the moment you have a side hustle, a 1099 contract, or a windfall, you cross the line.
Unlike the failure-to-file penalty, the underpayment penalty works like interest. The IRS charges roughly 8% annual interest on whatever amount you should have paid each quarter but didn\'t. It runs from the original due date until you either catch up or file your return.
A subtle point most people miss: the penalty is calculated quarter by quarter. If you pay Q1, Q3, and Q4 but skip Q2, you still owe a penalty on the missed Q2 amount — even if your total payments for the year cover everything. The IRS expects the money on schedule, not in lump sums.
The "100% of last year\'s tax" safe harbor is the easiest one to plan around — divide last year\'s total tax by four and pay that amount each quarter.
Trying to remember four separate dates spread across a year is the actual hard part. The IRS doesn\'t send you a quarterly bill — you\'re expected to know the date, calculate the amount, and pay on time, four times a year, every year.
The reliable approach: set four separate yearly reminders, one for each quarter. Each fires a week before its due date with notifications 7, 3, and 1 day out plus on the day. Once set up, the reminders run automatically every year — no maintenance needed.
Fire date: April 15. Same date as your annual federal filing — easy to remember once.
Fire date: June 15. Two months later. This is the one most people forget.
Fire date: September 15. Three months later — same week as Q4 of the prior year for many small businesses.
Fire date: January 15 of the next year. Easy to miss in the holiday rush.
Create the first reminder using the form at the top of this page (Q1). After confirming, repeat the process for the other three dates. Each one repeats yearly on its own.
The dates and rules around the main April 15 deadline.
April 15, June 15, September 15, and January 15 of the following year. For tax year 2026 specifically: April 15, 2026 (Q1), June 15, 2026 (Q2), September 15, 2026 (Q3), and January 15, 2027 (Q4). The IRS quarters are not evenly spaced — Q1 covers 3 months, Q2 covers 2 months, Q3 covers 3 months, Q4 covers 4 months.
Anyone who expects to owe more than $1,000 in tax for the year after subtracting withholding and credits. This typically includes freelancers, self-employed workers, gig workers, landlords, and people with significant investment income or capital gains. W-2 employees with adequate withholding usually don't need to file estimates.
The IRS charges an underpayment penalty, which works like interest on the unpaid amount until you catch up. The rate is currently around 8% annual, calculated quarterly. The penalty applies even if you eventually pay the full amount when filing — including filers who make three of four payments but skip one.
You can pay more than the required amount each quarter, including paying everything by April 15. But you cannot pay less for early quarters and make it up at the end without triggering the underpayment penalty. The IRS calculates the penalty quarter by quarter, not annually.
Three safe harbors. Pay at least 90% of the current year's tax through the year. Or pay 100% of last year's total tax (110% if your AGI was over $150,000). Or owe less than $1,000 at filing time after withholding. Meeting any one of these protects you from the penalty.
It's a historical quirk of the IRS tax calendar. Q1 covers January–March (due April 15). Q2 covers only April–May (due June 15). Q3 covers June–August (due September 15). Q4 covers September–December (due January 15). The dates are fixed even though the periods are uneven.
You can set four separate yearly reminders, one for each quarter — that's the most reliable approach since each date repeats every year on the same day. The form below pre-fills April 15 for Q1. Set additional reminders for June 15, September 15, and January 15 after creating the first.
Start with Q1 (April 15) below. Repeat for June 15, September 15, and January 15. Free, no account, yearly recurrence built in.
Set Q1 ReminderLast modified: